sql material

Suresh

Data: Data is the most important component in any work that we do; Data means collection of information or collection of raw facts.

Ex: 1. Text files 2. Facts 3. Figures (photos) 4. Audios 5. Videos etc...

Database: collection of related data.

DBMS :( Database Management System)

Data Base Management System is the management system or maintenance system on databases. (Or) It is a suit of software program for creating, maintaining & manipulating the data in database. (Or)It allows the users to insert the data, to retrieve the data, to modify the data and to delete the data.

Properties: 1. Create 2. Insert 3. Update 4. Delete 5. Select (query) 6. Low level security etc...

Ex: FoxPro, ims (information management system)

The first databases of kind existed in the form of files.A file is nothing but collection of records.A Record is nothing but collection of information or data.But the file system was not very efficient .it was crippled by slow data search speed. It

includes the following Drawbacks.1.Security2.Data Redundancy3.Data Integrity4.Concurrency Control5.Slow in Process6. File system: in a dbms database, data must be stored in the form of files only

Note: basic property of file system is independent and individual, means each and every file is unique AND relation is not possible between data files

7. Low level security, No Login name No Password.

RDBMS (Relational Database Management System):

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Data must be stored in the form of tables only Relation between Tables is possible

Table: It is collection of columns and rows, X axis directions are rows and Y axis directions are columns

Relation: Creating internal dependencies between Database Tables

Ex of RDBMS:

1. Sqlserver 2. Oracle3. Db2 (Database 2000, IBM)4. Mysql (open source)5. ms-access6. Postgresql (open source)7. Sybase8. Tera dataEtc.....

Terminology:

1. Table -- Entity2. Column (field) -- Attribute3. Row (record) -- Tupple4. Duplicate data (Repeated data) – Data Redundancy

Metadata: Data about data, it describes characteristics of data

Ex: Description of a table

Syn: sp_help <TN>

Ex: sp_help EMP

Note: <TN> stands for Table name

Data models:

1. Hierarchy data model2. Network data model3. Relational data model

Note: Currently all RDBMS Databases following RELATIONAL DATA MODEL

Adv of Relational Data model:

Relation Perfect solution for duplicate data and null values Normalization

Normalization: It is a process of eliminating duplicate data from the database.

EF CODD RULES:

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Sqlserver 2005:

1. It is RDBMS database2. It is a product of Microsoft3. It is case insensitive4. It is platform dependant-- it is compatible for windows OS5. User friendly

History: Introduced in 1994

Sqlserver 4.0 Sqlserver 5.0 Sqlserver 6.0 Sqlserver 6.5 Sqlserver 7.0 Sqlserver 8.0(2000) Sqlserver 9.0(2005) Sqlserver 10.0(2008)

Editions (flavors):

1. Enterprise edition2. Standard edition3. Developer edition4. Mobile edition5. Personal edition (express edition) free

Software Requirements:

1. OS

Windows xp sp2 or sp3

Windows server 2000 Windows server 2003 Windows server 2008

Windows Vista

Windows 7

2. Windows installer: It is a default component of Windows; we can download it from www.microsoft.com

3. IIS (internet information services):

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It is an application server from MICROSOFT

Hardware requirements:

1. Processor:

It supports both 32 bit, 64 bit

Ex:

1. Pentium 42. Amd athlon

2. Hard disk:

500 mb (MICROSOFT) 1 GB (Mine)

3. Ram:

512mb(MICROSOFT) 1 GB(Mine)

SQL -- structured query language

Sequel-- structured English query language

FEATURES OF SQL SERVER:

1. Security: Provides login and password to interact with data in database2. Data Redundancy: Less Data reputation3. Data Integrity: Data validation/Data Checking Process facility4. Backup and Recovery(Restore) 5. Introducing support for XML6. User defined function are introduced.7. OLAP (online analytical process) services available in SQL server 7.0 are now called as SQL

server 2005 analysis services

Things to Observe:

1. While writing the Queries using T-SQL in SQL Server Management Studio we need not to follow any particular case. Because T-SQL is case insensitive language.

2. After writing the Query, we need to select that query using either mouse or keyboard.3. Now Press F5 (Execute Key).4. Then the results are displayed in a separate window called Result window or Result

Pane.5. Use Ctrl+R to Hide/Show the Result window or Result Pane.6. Use F8 for Object Explorer

Note:1. SQL SERVER can handle nearly 32767 Databases2. Each Database can handle nearly 2 billion Database Objects.3. Each Table can handle nearly 1024 columns4. Each Table can handle nearly 1 million Rows

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SQLSERVER is two parts, they are

1. Tsql :( Transact sql)

2. Tsql programs

Tool:

1. Management studio: It contains two parts, they are

1. Cui (Character user interface):

Sqlscripting can be written in *newqury* option By using execute button or f5 we can execute the script

2. Gui (Graphical user interface):

It is Navigations part of the management Studio.

We can connect to GUI by using *summary* option.

Path: start programs sqlserver 2005 Management Studio (click)

Inside management studio window provide following information

1. Server type-- database engine2. servername-- database server name3. authentication--

A. Windows’s authentication

This user must be an OS user

B. Sqlserver authentication

UN: sa (sysadmin-- DBA)Pw: ******** (Depends Upon Installation)

Databases:

1. System databases:

These are inbuilt or default databases Along with installation of Sqlserver 2005 we can get system databases System databases monitors entire database engine

Note: User can’t create and delete a system database

A. masterB. modelC. msdbD. tempdb

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E. MS resources

Description

master Database

Records all the system-level information for an instance of SQL Server.

msdb Database

It is used by SQL Server Agent for scheduling alerts and jobs.

model Database Template database

Resource Database

It is a read-only database that contains system objects that are included with SQL Server 2005. System objects are physically persisted in the Resource database, but they logically appear in the sys schema of every database.

tempdb Database

It is a workspace for holding temporary objects or intermediate result sets.

2. User databases:

These database created and maintained by the users explicitly

Ex:

CREATE DATABASE sureshON PRIMARY

(NAME=suresh,FILENAME="C:\MSSQL\vadde\suresh.mdf",SIZE=100,MAXSIZE=200,FILEGROWTH=25%)Log on(NAME=suresh_log,FILENAME="C:\MSSQL\vadde\suresh_log.ldf",SIZE=100,MAXSIZE=200,FILEGROWTH=25%)

SQL Server Data Types:

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http://msdn.microsoft.com/en-us/library/ms190768.aspx










Suresh

Character strings:

Data type Description Storage

char(n) Fixed-length character string. Maximum 8,000 characters n

varchar(n) Variable-length character string. Maximum 8,000 characters

varchar(max) Variable-length character string. Maximum 1,073,741,824 characters

text Variable-length character string. Maximum 2GB of text data

Unicode strings:


nchar(n) Fixed-length Unicode data. Maximum 4,000 characters

nvarchar(n) Variable-length Unicode data. Maximum 4,000 characters

nvarchar(max) Variable-length Unicode data. Maximum 536,870,912 characters

ntext Variable-length Unicode data. Maximum 2GB of text data

Binary types:


bit Allows 0, 1, or NULL

binary(n) Fixed-length binary data. Maximum 8,000 bytes

varbinary(n) Variable-length binary data. Maximum 8,000 bytes

varbinary(max) Variable-length binary data. Maximum 2GB

image Variable-length binary data. Maximum 2GB

Number types:


tinyint Allows whole numbers from 0 to 255 1 byte

smallint Allows whole numbers between -32,768 and 32,767 2 bytes

int Allows whole numbers between -2,147,483,648 and 2,147,483,647 4 bytes

bigint Allows whole numbers between -9,223,372,036,854,775,808 and 9,223,372,036,854,775,807

8 bytes

decimal(p,s) Fixed precision and scale numbers.

Allows numbers from -10^38 +1 to 10^38 –1.

The p parameter indicates the maximum total number of digits that can be stored (both to the left and to the right of the decimal point). p must be a value from 1 to 38. Default is 18.

The s parameter indicates the maximum number of digits stored to the right of the decimal point. s must be a value from 0 to p. Default value is 0

5-17 bytes

numeric(p,s) Fixed precision and scale numbers. 5-17 bytes

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Allows numbers from -10^38 +1 to 10^38 –1.

The p parameter indicates the maximum total number of digits that can be stored (both to the left and to the right of the decimal point). p must be a value from 1 to 38. Default is 18.

The s parameter indicates the maximum number of digits stored to the right of the decimal point. s must be a value from 0 to p. Default value is 0

small money Monetary data from -214,748.3648 to 214,748.3647 4 bytes

money Monetary data from -922,337,203,685,477.5808 to 922,337,203,685,477.5807

8 bytes

float(n) Floating precision number data from -1.79E + 308 to 1.79E + 308.

The n parameter indicates whether the field should hold 4 or 8 bytes. Float (24) holds a 4-byte field and float (53) holds an 8-byte field. Default value of n is 53.

4 or 8 bytes

real Floating precision number data from -3.40E + 38 to 3.40E + 38 4 bytes

Date types:


datetime From January 1, 1753 to December 31, 9999 with an accuracy of 3.33 milliseconds

8 bytes

datetime2 From January 1, 0001 to December 31, 9999 with an accuracy of 100 nanoseconds

6-8 bytes

smalldatetime From January 1, 1900 to June 6, 2079 with an accuracy of 1 minute 4 bytes

date Store a date only. From January 1, 0001 to December 31, 9999 3 bytes

time Store a time only to an accuracy of 100 nanoseconds 3-5 bytes

datetimeoffset The same as datetime2 with the addition of a time zone offset 8-10 bytes

timestamp Stores a unique number that gets updated every time a row gets created or modified. The timestamp value is based upon an internal clock and does not correspond to real time. Each table may have only one timestamp variable

Other data types:

Data type Description

sql_variant Stores up to 8,000 bytes of data of various data types, except text, ntext, and timestamp

uniqueidentifier Stores a globally unique identifier (GUID)

xml Stores XML formatted data. Maximum 2GB

cursor Stores a reference to a cursor used for database operations

table Stores a result-set for later processing

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TSQL:

This is a 4th generated intermediate language between user and SQL Server. Whenever user wants to interact with SQL Server, he has to interact with SQL Server through T-SQL. It includes the following Sub Languages

Sublanguages:

1. DDL (data definition language)2. DML (data manipulation language)3. DRL (data retrieval language) or QL (query language)4. TCL (transaction control language)5. DCL (data control language) -- DBA

1. DDL:

Commands:

1. Create 2. Truncate3. Drop4. Alter

1. Create: used to create database, tables and other database objects

syn: create table <tn>(col1 dt(l),col2 dt(l),col3 dt(l))

Ex: create table tab1 (id int, ename varchar (20), DOB datetime)

Note: Max length of a table name and column name is 30; it may include alphabets, digits 0 to

9 and special character '_' (Underscore). It is known as "naming conventions". Max of 1024 columns can be included into a table.

2. Truncate: used to delete entire data from a table and its not possible to delete selected or specific rows from a table by using truncate command.

Ex:

Assume that Tab1 is a table, contains 10 rows of data, now

Entire data of Tab1 table= 10rows

Selected or specific data of Tab1 table<entire data

1 to 9 rows are known as selected or specific data

Syn: truncate table <TN>

Ex: truncate table tab1

3. Drop: used delete a table from the database

Syn: drop table <TN>

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Ex: drop table tab1

4. Alter:

Alter+add: used to add a column to the table

Syn: alter table <TN> add column_name DT (l), column_name DT (l)

Ex: alter table tab1 add sal numeric (7, 2), comm Numeric (5, 2), address varchar (50)

Alter+drop: used delete columns from the table

Syn: alter table <TN> drop column column_name

Ex: alter table tab1 drop column address

Alter+alter: used change the data type and length of data type of a column

Note: Column is empty then only we can change data type

Syn: alter table <TN> alter column column_name DT (l)

Ex: alter table tab1 alter column id varchar (20)

Miscellaneous:

System stored procedures: Directly we can execute them when ever required

1. Getting description of a table (metadata)

Syn: sp_help <TN>

Ex: sp_help tab1

2. Getting description of a database:

Syn: sp_helpdb <dbname>

Ex: sp_helpdb Suresh

3. Displaying list of tables in a database

Syn: sp_tables

Ex: sp_tables

4. Changing name of a table

Syn: sp_rename <TN>, <new_name>

Ex: sp_rename tab1, employ

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5. Retrieving list of Databases

Syn: sp_databases

DML:

Commands:

1. Insert2. Update3. Delete

1. Insert: Used to insert (add) data into tables

Syn: insert into <TN> values (col1, col2, col3)

Ex: insert into employ values ('a12','ramesh','12-apr-07', 3000, 30) Id name DOB sal comm

Note: while working with char and date time data we should use single quotes

Inserting null values into table:

Student table contains 5 columns; now insert null value into comm column

Ex: insert into employ (id, name, DOB) values ('a13','ravi','21-jul-06', 2000)

Ex: insert into employ values ('a14','ramesh','12-apr-06', 5000, null)

2. Update: used to update (replace) old data with new data, it is two types they are

A. Updating entire data in a column:

Syn: update <TN> set column_name=new_value

Ex: update employ set sal=5000

B. Updating selected data in a column:

Syn: update <TN> set column_name=new_value where <condition>

Ex: update employ set sal=3000 where id='a12'

3. Delete: used to delete entire data and selected data from a table

A. Deleting entire data from a table:

Syn: delete from <TN>

Ex: delete from employ

B. Deleting selected data from a table:

Syn: delete from <TN> where <condition>

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Ex: delete from employ where id='a14'

DRL: Commands:

1. Select: used to retrieve or display data from table or tables

Note: Retrieving data from single table is 4 types

1. Retrieving entire data (all columns and all rows) from a table

Syn: select*from <TN>

Ex: select*from employ

Note: * stands for entire columns of the table

2. Retrieving all columns and selected rows from a table

Syn: select*from <TN> where <condition>

Ex: select*from employ where id='a12'

3. Retrieving entire data from selected columns

Syn: select col1, col2 from <TN>

Ex: select ename, fees from employ

4. Retrieving selected rows from selected columns

Syn: select col1, col2 from <TN> where <condition>

Ex: select name, fees from employ where id='a13'

DCL: It is used to control the data between different user accounts. It includes the following statements.

1. GRANT Statement2. REVOKE Statement

Grant Statement: This statement is used to grant the permissions (INSERT, SELECT, UPDATE, DELETE) on a specific table to different user accounts.

Syntax:

GRANT {ALL/SPECIFIC PERMISSIONS} ON TABLENAMETO USER ACCOUNT (S) [WITH GRANT OPTION]

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WITH GRANT OPTION: When any user got the permissions on a specific table from other user with this option, then that user can grant the permissions on that same table to another user account. At that time sub user acts as owner.

Ex:

GRANT ALL ON EMP TO RAMESH WITH GRANT OPTION

From the above statement RAMESH user account got all permissions on EMP table from SA user account. Mean time RAMESH can give the permissions on EMP to another user account because he got the permissions WITH GRANT OPTION.

Ex:

GRANT INSERT, SELECT ON EMP TO SURESH

Now SURESH can perform select and insert operations on EMP table.But SURESH cannot perform update and delete operations on EMP table because he does not have the corresponding permissions.

Revoke Statement: This statement is used to revoke the permissions (INSERT, SELECT, UPDATE, DELETE) on a specific table from different user accounts.

Syntax:

REVOKE {ALL/SPECIFIC PERMISSIONS} ON TABLENAMEFROM USER ACCOUNT (S) [CASCADE]

CASCADE: Using this option we can destroy the communication link between user accounts more over from the main user it self we can revoke the permissions from all sub users.

Ex:

REVOKE ALL ON EMP FROM SUBBU CASCADE

The above statement revokes the permissions on EMP table from SUBBU and SURESH. Now SUBBU and SURESH users cannot access EMP table.

TCL:

Transaction is nothing but a unit of work. We can control these transactions using the following statements

ROLLBACK StatementCOMMIT StatementSAVE TRAN [SACTION]

ROLLBACK Statement: This statement is used to cancel a particular performed transaction. To perform this statement in SQL Server we have to follow any one of the below 2 approaches.

Approach 1: SET IMPLICIT_TRANSATIONS ON

This approach is only to cancel a single recently performed operation.

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Ex: SET IMPLICIT_TRANSATIONS ONSELECT * FROM EMPDELETE FROM EMPSELECT * FROM EMPROLLBACKSELECT * FROM EMP Approach 2: Explicit Transactions

To approach is to cancel recently performed multiple operations.

Syntax: BEGIN TRAN ------------- GO ------------- GO -------------

ROLLBACK TRAN

Note: GO is query separator

Ex:

BEGIN TRANINSERT INTO DEPT VALUES (50,’TRA’,’AUS’)GOUPDATE EMP SET SAL=SAL+1000 WHERE EMPNO=11GODELETE FROM STUDENT WHERE SNO=101

Select the entire transaction and press F5 for one time

ROLLBACK TRAN

The ROLLBACK statement cancels INSERT on Dept, UPDATE on EMP and DELETE on Student tables.

COMMIT Statement: This statement makes a transaction permanent. It is not possible to rollback the committed transaction.

Ex:

SELECT * FROM EMPDELETE FROM EMPSELECT * FROM EMPCOMMITSELECT * FROM EMP

The COMMIT statement deletes the data from EMP permanently. It is not possible to ROLLBACK the delete operation.

Ex:

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BEGIN TRANINSERT INTO DEPT VALUES (50,’TRA’,’AUS’)GOUPDATE EMP SET SAL=SAL+1000 WHERE EMPNO=11GODELETE FROM STUDENT WHERE SNO=101

Select the entire transaction and press F5 for one time

COMMIT TRAN

The above COMMIT TRAN makes all three transactions permanent. We cannot ROLLBACK the transactions.

SAVE TRAN Statement: This statement is used to COMMIT/ROLLBACK a particular performed transaction from the set of transactions. It is associated with alphabets in order to save the transactions.

BEGIN TRANSAVE TRAN AINSERT INTO DEPT VALUES (50,’TRA’,’AUS’)SAVE TRAN BUPDATE EMP SET SAL=SAL+1000 WHERE EMPNO=11SAVE TRAN CDELETE FROM STUDENT WHERE SNO=101

ROLLBACK TRAN C (The delete operation will be cancelled)COMMIT TRAN B (The update operation performed permanently we cannot rollback)

TABLES FOR PRACTICALS:

1.CREATE TABLE EMP (EMPNO NUMERIC(4) NOT NULL, ENAME VARCHAR(10), JOB VARCHAR(9), MGR NUMERIC(4), HIREDATE DATETIME, SAL NUMERIC(7, 2), COMM NUMERIC(7, 2), DEPTNO NUMERIC(2));

DATA:

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INSERT INTO EMP VALUES (7369, 'SMITH', 'CLERK', 7902,'17-DEC-1980', 800, NULL, 20);INSERT INTO EMP VALUES (7499, 'ALLEN', 'SALESMAN', 7698,'20-FEB-1981', 1600, 300, 30);INSERT INTO EMP VALUES (7521, 'WARD', 'SALESMAN', 7698,'22-FEB-1981', 1250, 500, 30);INSERT INTO EMP VALUES (7566, 'JONES', 'MANAGER', 7839,'2-APR-1981', 2975, NULL, 20);INSERT INTO EMP VALUES (7654, 'MARTIN', 'SALESMAN', 7698,'28-SEP-1981', 1250, 1400, 30);INSERT INTO EMP VALUES (7698, 'BLAKE', 'MANAGER', 7839,'1-MAY-1981', 2850, NULL, 30);

INSERT INTO EMP VALUES (7782, 'CLARK', 'MANAGER', 7839,'9-JUN-1981', 2450, NULL, 10);INSERT INTO EMP VALUES (7788, 'SCOTT', 'ANALYST', 7566,'09-DEC-1982', 3000, NULL, 20);INSERT INTO EMP VALUES (7839, 'KING', 'PRESIDENT', NULL,'17-NOV-1981', 5000, NULL, 10);INSERT INTO EMP VALUES (7844, 'TURNER', 'SALESMAN', 7698,'8-SEP-1981',1500, 0, 30);

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INSERT INTO EMP VALUES (7876, 'ADAMS', 'CLERK', 7788,'12-JAN-1983', 1100, NULL, 20);INSERT INTO EMP VALUES (7900, 'JAMES', 'CLERK', 7698,'3-DEC-1981', 950, NULL, 30);INSERT INTO EMP VALUES (7902, 'FORD', 'ANALYST', 7566,'3-DEC-1981', 3000, NULL, 20);INSERT INTO EMP VALUES (7934, 'MILLER', 'CLERK', 7782,'23-JAN-1982', 1300, NULL, 10);

2.CREATE TABLE DEPT (DEPTNO NUMERIC(2), DNAME VARCHAR(14), LOC VARCHAR(13) );

DATA:

INSERT INTO DEPT VALUES (10, 'ACCOUNTING', 'NEW YORK');INSERT INTO DEPT VALUES (20, 'RESEARCH', 'DALLAS');INSERT INTO DEPT VALUES (30, 'SALES', 'CHICAGO');INSERT INTO DEPT VALUES (40, 'OPERATIONS', 'BOSTON');

3.CREATE TABLE SALGRADE (GRADE NUMERIC, LOSAL NUMERIC,

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HISAL NUMERIC);DATA:

INSERT INTO SALGRADE VALUES (1, 700, 1200);INSERT INTO SALGRADE VALUES (2, 1201, 1400);INSERT INTO SALGRADE VALUES (3, 1401, 2000);INSERT INTO SALGRADE VALUES (4, 2001, 3000);INSERT INTO SALGRADE VALUES (5, 3001, 9999);

Operators:

1. Arithmetic operators: +, -,*, /

1. +:

Select sal, sal+1000 from EMP

2.-:

Select sal, sal-100 from EMP

3.*:

Select sal, sal*12 from EMP

4. /:

Select sal, sal/2 from EMP

2. Assignment operator’s :( relational operators)

=, <> or ! =,>,>=,<,<=

1. =:

Select*from EMP where deptno=20

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2. <> or! =:

Select*from EMP where deptno<>20

3.>:

Select*from EMP where sal>3000

4.>=:

Select*from EMP where sal>=3000

5. <:

Select*from EMP where sal<3000

6. <=:

Select*from EMP where sal<=3000

3. Logical operators: and, or, not

Ex: in maths two conditions are there, condition A and condition B

A and B-- both conditions must be satisfied

A or B-- if anyone satisfied then we can get output

1. And:

Select*from EMP where sal>3000 and deptno=20

2. Or:

Select*from EMP where sal>3000 or deptno=20

Between operator :( Range operator)

Ex: select*from EMP where sal between 2000 and 5000

Not between:

Ex: select*from EMP where sal not between 2000 and 5000

In operator :( Minimizes searching time)

Select*from EMP where ename in ('Scott', 'Turner’, ‘Suresh')

Not in:

Select*from EMP where ename not in ('scott','turner','suresh')

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Like operator :( Pattern matching)

Ex: select*from EMP where ename like’s%'

S%-- ename starts with s%s-- ename ends with s%s%-- somewhere s in ename_s%-- second character is s from beginning%s_ -- second from ending is s in ename

Note: _ (underscore) denotes one character

Not like operator:

Select*from EMP where ename not like’s%'

Alias:

Second or duplicate name, can be assigned to a table or column

Alias is temporary

Ex:

Select sal*12 from EMP

Select sal*12 annual Sal from EMP

Note: annual Sal is alias for sal*12

Inbuilt functions:

1. Aggregate functions :( Group functions)

1. Sum ():

Select sum (sal) from EMP

2. Average ():

Select avg (sal) from EMP

3. Max ():

Select max (sal) from EMP

4. Min ():

Select min (sal) from EMP

5. Count (): it counts number of rows

Select count (*) from EMP

Select count (ename) from EMP

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Select count (comm) from EMP

Note: 1. Count Function doesn’t consider null as a value.2. COUNT function does not count the rows of the column whose data type is BIGINT, In

such situations we have to use COUNT_BIG function

6. Standard deviation ():

Select stdev (sal) from EMP

7. Variance ():

Select var (sal) from EMP

DISTINCT ( ): This function displays the different values available for a specific column. It considers one NULL value.

Ex: SELECT DISTINCT (DEPTNO) AS DIFF_VALUES FROM EMP

DIFF_VALUES1020

Ex: SELECT COUNT (DISTINCT( DEPTNO)) AS NO_OF_ROWS FROM EMP

NO_OF_ROWS2

2. Numeric functions:

1. Absolute:

Select abs (-9.5)

O/p: 9.5

2. Ceiling:

Select ceiling (9.01)

O/p: 10

3. Floor:

Select floor (9.9)

O/p: 9

4. Square root:

Select sqrt (144)

O/p: 12

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5. Power:

Select power (3, 3)

O/p: 27(3*3*3)

6. Square:

Select square (3)

O/p: 9(3*3)

7. Pi ():

Select pi ()

O/p: 3.14(22/7)

8. Log:

Select log (2)

O/p: 0.693147180559945

9. Exp:

Select exp (2)

O/p: 7.38905609893065

10. ROUND (M, N):

IT WILL ROUND THE VALUE OF M TO NEAREST WHOLE NUMBER OF IT WILL AROUND.

SELECT ROUND (15.143)



SELECT ROUND (21.132,1)


3. Character functions :( String functions)

1. Length:

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Select Len ('Hyderabad')

O/p: 9

2. Upper:

Select upper ('Hyderabad')

O/p: HYDERABAD

3. Lower:

Select lower ('HYDERABAD')

O/P: hyderabad

4. Reverse:

Select reverse ('Malayalam')

O/p: Malayalam

Select reverse ('school')

O/p: loohcs

5. Replace:

Select replace ('hyderabad','hyd','cyb')

O/p: cyberabad

6. Substring:

Select substring ('hyderabad', 3, 5)

O/p: derab

7. ASCII (Character): It gives ASCII value of a character

Select ASCII (‘A’)

O/p: 65

Select ASCII (‘a’)

O/p: 97

8. Char (n): It gives character for given ASCII value

Select char (98)

O/p: b

Date time functions:

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1. Getdate ():

Select getdate ()

O/p: 2009-07-17 18:11:20.000

2. Getutcdate ():

Select getutcdate ()

O/p: 2009-07-17 12:42:09.263

3. Dateadd:

Select dateadd (dd, 7, getdate ())

O/p: 2010-04-27 15:24:15.827

4. Datediff:

Select datediff (mm,'03/26/04', getdate ())

O/p: 73

5. Date part:

Select datepart (yy, getdate ())

O/p: 2010

Select datepart (mm, getdate ())

O/p: 4

Select datepart (dd, getdate ())

O/p: 20

6. Date name:

Select datename (DW, getdate ())

O/p: Tuesday

Set operators:

a= {1, 2, 3}b= {3, 4, 5}

1. A union B= {1, 2, 3, 4, 5}

2. A union all B= {1, 2, 3, 3, 4, 5}

Note: union all retrieves duplicate data

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3. A intersect B= {3}

4. A except B = A minus B= {1, 2}

1. Union:

SELECT EMPNO FROM EMPUNION SELECT DEPTNO FROM DEPT

2. Union all:

SELECT EMPNO FROM EMPUNION ALLSELECT DEPTNO FROM DEPT

3. Intersect:

SELECT EMPNO FROM EMPINTERSECTSELECT DEPTNO FROM DEPT

4. Except:

SELECT EMPNO FROM EMPEXCEPTSELECT DEPTNO FROM DEPT

Group by clause:

Used to group similar data in the output

Conjunction of the similar data

Used to divide the table into number of subgroups based on a specific column.

Minimum single group or aggregate function is mandatory

If column contains similar data then only we can use it into group by clause

Display the number of employee working in different jobs of EMP table

Ex: Select job, count (job) from EMP Group by job

Display max and min salaries of employees who are working in different deptno's of EMP table

Ex: Select deptno, max (sal), min (sal) from EMP Group by (deptno)

Ex: SELECT DEPTNO, MAX (SAL) AS HISAL, MIN (SAL) AS LOSAL, SUM (SAL) AS TOTSAL, AVG (SAL) AS AVGSAL FROM EMP GROUP BY DEPTNO

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Having clause:

It is an arithmetical expression

It can be used as an extension of group by clause and we can’t use where clause after group by clause

This clause is used to evaluate a condition with group by clause. Generally for evaluating conditions we will use WHERE clause, but where clause does not support by group by clause.

Ex: Select job, count (deptno) from EMP Group by job Having count (deptno)>2

Ex: SELECT DEPTNO, MAX (SAL) AS HISAL, MIN (SAL) AS LOSAL, SUM (SAL) AS TOTSAL, AVG (SAL) AS AVGSAL FROM EMP GROUP BY DEPTNO HAVING AVG (SAL)>10000

Order by clause:

It is temporary sorting of the data either in ascending order or in Descending order

Default is ascending order

Ascending:

Ex: Select*from EMP order by sal

Descending:

Ex: Select*from EMP order by sal desc

Clause precedence:

1. Where clause2. Group by clause3. Having clause4. order by clause

Joins:

Used to retrieve data from multiple tables

Joins plays major role in performance tuning

Joins comes under temporary relations

We need a common column or common data column in multiple tables

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Two tables are there, they are EMP and DEPT am creating joins between them

Both tables contains a common column i.e. deptno, so that we can create Joins between EMP, DEPT tables

Formula: no. of joins=no. of tables-1

Types of JOINS:

1. Inner join :( Equi join)

We are retrieving data from EMP, DEPT tables

Ex:

Select empno, ename, sal, d.deptno, dname, loc from EMP eInner join DEPT d on e.deptno=d.deptno

Note: Query retrieves equal number of rows from both tables

2. Outer join: This is three types

1. Left outer join:

Select empno, ename, sal, d.deptno, dname, loc from EMP eLeft outer join DEPT d on e.deptno=d.deptno

It retrieves condition satisfies and non satisfied data from left side table of the condition i.e. EMP, it retrieves only condition satisfied data from right side table of the condition i.e. DEPT

2. Right outer join:

Select empno, ename, sal, d.deptno, dname, loc from EMP eRight outer join DEPT d on e.deptno=d.deptno

It retrieves condition satisfied from left side table of the condition i.e. EMP, it retrieves condition satisfied data and non satisfied data from right side table of the condition i.e. DEPT

3. Full outer join:

This is combination of both right and left outer joins.

Select empno, ename, sal, d.deptno, dname, loc from EMP eFull outer join DEPT d on e.deptno=d.deptno

It retrieves condition satisfied and non satisfied data from both tables.

3. Non-equi join: EMP table contains a column sal, in SALGRADE table, we got two columns losal and hisal so that we can define a join condition.

Select empno, ename, sal, grade from EMP e, SALGRADE s where e.sal between s.losal and s.hisal

By using above query we can map employees and their grades.

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4. Cross join :( Cartesian product)

a= (1, 2, 3)b= (4, 5, 6)

A*B=3*3=9

EMP table contains 14 rowsDept table contains 4 rows

Cross join of EMP, DEPT tables produces 56 rows

Ex:

Select*from EMP cross join DEPT

Creating a table by copying data and structure from another table:

Syn:

Select*into <TN> from <existing_table>

Ex:

Select*into EMP1 from EMP

Ex: (Oracle)

Create table EMP1 as select*from EMP;

Creating a table by copying sturucture from another table:

In this by defining false condition we can avoid copying of data.

Syn:

Select*into <TN> from <existing_tabel> where <false_condition>

Ex:

Select*into EMP2 from EMP where 1=2

SUB-QUERIES:

It is a Combination of multiple queries or select statements.

Query with in a query is known as Sub-Query

Syn:

Select statement (Select statement) Outer query inner query

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Types:

1. Simple or single row sub query:

It returns only single row to the user

Ex: Retrieve second highest sal from EMP table

Select max (sal) from EMP where sal< (select max (sal) from EMP)

2. Nested sub query:

It is also simple sub query

It returns single row

Ex: Retrieve third highest sal from EMP table

Select max (sal) from EMP where sal< (select max (sal) from EMP whereSal< (select max (sal) from EMP))

Distinct: It eliminates duplications temporarily.

Ex:

A. Select sal from EMP

B. Select distinct (sal) from EMP

Formula for retrieving n highest salaries from EMP table:

Select max (sal) from EMP e where n= (select count (distinct (sal)) from EMP b where e.sal<b.sal)

N is a number which indicates position of the sal

N starts from zero

n=n-1

Formula for Min sal:

Select min (sal) from EMP e where n= (select count (distinct (sal)) from EMP b where e.sal>b.sal)

3. Co-related sub query:

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It can return single and multiple rows to the user

I want to retrieve deptno 20 data from EMP table, for that I want Satisfy the condition in dept table

Ex:

Select*from EMP where deptno= (select deptno from DEPT where dname='accounting')

Note: If a sub query sends multiple values to its nearest main query then we have to use IN operator between Main query and Sub query.

Ex: WAQ to display employee details, who are working under RAM dept.

SELECT * FROM EMP WHERE DEPTNO= (SELECT DEPTNO FROM EMP WHERE ENAME=’RAM’)

Ex: WAQ To display employee details, whose salary is greater than highest salary of 10th department

SELECT * FROM EMP WHERE SAL> (SELECT MAX (SAL) FROM EMP WHERE DEPTNO=10)

Ex: WAQ To display employee details, whose salary is greater than average salary of RAM department

SELECT * FROM EMP WHERE SAL> (SELECT AVG (SAL) FROM EMP WHERE DEPTNO=SELECT DEPTNO FROM EMP WHERE ENAME=’RAM’)

Constraints:

Set of rules which are used to improve functionality of tables

These are inbuilt rules

We can impose constraints on columns

Adv:

1. Creating permanent relations between tables

2. We can avoid duplications and null values

3. We can create permanent conditions

Note: We can create a constraint along with table creation this is of two types:

1. Column level Constraint: It can be created on single column

2. Table level Constraint: It can be created on multiple columns

Note: We can add a constraint to the existing table

Types:

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1. Primary key2. Unique constraint3. Check constraint4. Not null5. Foreign key (Referential integrity)

1. Primary key:

Properties:

It is unique It is not null

Column level Primary Key:

Syn: create table <TN> (col1 DT (l) constraint con_name primary key, col2 DT (l), col3 DT (l))

Ex: create table t1 (id int constraint p_key primary key, name varchar (20), DOB datetime)

In this we can create a constraint on single column only

Table level Primary key:

syn: create table <tn>(col1 dt(l),col2 dt(l),col3 dt(l), constraint con_name primary key(col1,col2))

Ex: create table t2 (id int, name varchar (20), DOB datetime, constraint p_key3 primary key (id, name))

We can create single constraint on multiple columns

Max of single primary key can be created on a table

If single primary key is working on multiple columns then it is known as "composite primary key"

2. Unique constraint:

Properties:

Unique It accepts single null value

Syn: create table <TN> (col1 DT (l) constraint con_name unique, col2 DT (l), col3 DT (l))

Ex: create table t3 (id int constraint u_con unique, dname varchar (20), loc varchar (20))

3. Check constraint: used to impose permanent conditions on columns

Syn: create table <tn>(col1 dt(l),col2 dt(l) constraint con_name check(condition),col3 dt(l))

Ex: create table t4 (id int, sal numeric (7, 2) constraint check_con check (sal>3000), commission numeric (5, 2))

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4. Not null: it doesn’t accept null values

Syn: create table <TN> (col1 DT (l) constraint con_name not null)

Ex: create table t5 (id int constraint n_null not null)

5. Foreign key:

It always references values from either primary key or unique constraint and there are no properties for foreign key.

It also known as referential integrity

This reference will be stored into database permanently, so that It is comes under permanent relation

Generally primary key and foreign are a part of different tables

Primary key table is known as parent or master table

Foreign key table is known as child or detail table

We can create primary key and foreign key in single table, that is known as "self referential integrity"

Note:

1. Primary key and foreign key columns data types must be same.

2. If the value existing in primary key then only we can insert same value into foreign key.

3. Foreign key accepts null values when it is referencing from unique constraint

syn: create table <tn>(col1 dt(l),col2 dt(l),col3 dt(l), constraint con_name foreign key(col1)references <tn2>(col1))

Ex: create table t6 (id int, address varchar (50), job varchar (20), constraint f_key foreign key (id) references t1 (id))

Adding constraint to a table:

Syn: alter table <TN> add constraint con_name type_constraint (col_list)

Ex: alter table t2 add constraint p_key3 primary key (id)

Dropping constraint:

Syn: alter table <TN> drop constraint con_name

Ex: alter table t2 drop constraint p_key3

Information regarding constraints of a table:

Syn: sp_helpconstraint <TN>

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Ex: sp_helpconstraint t1

Normalization:

Normalization is process of splitting the base table into multiple tables based on the theory of Functional Dependency.

ORNormalization is repetitive process in order to identify the functional dependencies among the columns and to remove them. If any functional dependency is occurred after the normalization process again we have to start the same process until all functional dependencies have been removed.

To do this Normalization we have to follow rules or conditions called Normal Forms.

Un-Normalized Table

EMPNO PROJNO ENAME PNAME SAL BUD DEPTNO DNAME LOC

11 (P1, P2) ---- (Pn1, Pn2) ----- ----- 10 -------- -----

22 (P2, P3) ---- (Pn2, Pn3) ----- ----- 10 -------- -----

33 (P1, P3) ---- (Pn1, Pn3) ----- ----- 20 -------- -----

EMPNO and PROJNO are Primary Keys called ‘COMPOSITE PRIMARY KEY’

FIRST NORMAL FORM (1NF): According to first normal form table should contain only single values columns. But in the above un-normalized table the columns PROJNO and PNAME contains multiple values.

To make the table into first normal form we should have to split the multiple values into single values.

EMPNO PROJNO ENAME PNAME SAL BUD DEPTNO DNAME LOC

11 P1 ---- Pn1 ----- ----- 10 -------- -----

11 P2 ---- Pn2 ----- ----- 10 -------- -----

22 P2 ---- Pn2 ----- ----- 10 -------- -----

22 P3 ---- Pn3 ----- ----- 10 -------- -----

33 P1 ---- Pn1 ----- ----- 20 -------- -----

33 P3 ---- Pn3 ----- ----- 20 -------- -----

SECOND NORMAL FORM (2NF):

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According to second normal form table should be in 1NF and we should have to remove Partial Functional Dependency.

In the above table DEPTNO non-key column dependent part of the Primary key column i.e. EMPNO. It means there existed Partial functional dependency.

To make the table into second normal form we have to divide the table into multiple tables.

PROJ-INFO

PROJNO PNAME BUD

P1 Pn1 ------

P2 Pn2 ------

P3 Pn3 ------

EMP-INFO

EMPNO ENAME SAL DEPTNO DNAME LOC

11 ---- ---- 10 ------ -----

22 ---- ---- 10 ------ -----

33 ---- ---- 20 ------ -----

THIRD NORMAL FORM (3NF):

According to second normal form table should be in 2NF and we should have to remove Transitive Functional Dependency.

In the above EMP-INFO table non-key column DNAME dependent part on the other non- key column i.e.DEPTNO. It means there existed Transitive functional dependency.

To make the table into third normal form we have to divide the table into multiple tables.

PROJ-INFO

PROJNO PNAME BUD

P1 Pn1 ------

P2 Pn2 ------

P3 Pn3 ------

EMP-INFO DEPT-INFO

EMPNO ENAME SAL DEPTNO DNAME LOC

11 ---- ---- 10 ------ -----

22 ---- ---- 20 ------ -----

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33 ---- ----

Views:

A View is nothing but an image table or virtual table, which is created for a base table. A view can be created by taking all values from the base table or by taking only selected values from base table. There are two types’ views available in SQL Server.

1. Simple Views2. Complex Views

Note: If we perform any modifications in base table, then those modifications automatically effected in view and vice-versa.

1. Simple Views: Creating View by taking only one single base table.

Syntax:

CREATE VIEW VIEWNAME [WITH ENCRYPTION]AS SELECT * FROM TABLENAME [WHERE CONDITION]

[WITH CHECK OPTION]

Ex: CREATE VIEW V1 AS SELECT * FROM EMPINSERT INTO V1 VALUES (55,’RAVI’, 10000, 10)

The above insert statement inserts the values into base table EMP as well as into view V1.

Ex:

CREATE VIEW V2 AS SELECT * FROM EMP WHERE DEPTNO=10

INSERT INTO V2 VALUES (66,’BABBU’, 25000, 10)

The above insert statement inserts the values into base table EMP as well as into view V2.

INSERT INTO V2 VALUES (77,’AMAR’, 15000, 20)

The above insert statement inserts the values into only base table EMP but not into view V2 because according to the definition of V2 user supplied values are invalid values. It means invalid values are inserting into base table EMP. To stop this kind of operations we have to create the view with ‘WITH CHECK OPTION’.

Ex:

CREATE VIEW V3 AS SELECT * FROM EMP WHERE DEPTNO=10 WITH CHECK OPTION

INSERT INTO V3 VALUES (88,’TEJA’, 25000, 20)

The above insert statement cannot insert the values into base table EMP as well as into view V3.

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SP_HELPTEXT: This stored procedure is used to display the definition of a specific view.

Syntax:

SP_HELPTEXT VIEWNAME

Ex: SP_HELPTEXT V1

Output: CREATE VIEW V1 AS SELECT * FROM EMP

WITH ENCRYPTION: Once we create any view with ‘WITH ENCRYPTION’ then we cannot find the definition of that particular view using SP_HELPTEXT stored procedure because this encryption option hides the definition.

Ex:

CREATE VIEW V4 WITH ENCRYPTION AS SELECT * FROM EMP WHERE DEPTNO=20

SP_HELPTEXT V4

Output: The text for object v4 is encrypted

To decrypt the definition of view V4 we have to follow the below approach1. Replace CREATE with ALTER2. Remove WITH ENCRYPTION keyword

Ex:

ALTER VIEW V4 AS SELECT * FROM EMP WHERE DEPTNO=20

SP_HELPTEXT V4

CREATE VIEW V4 AS SELECT * FROM EMP WHERE DEPTNO=20

2. Complex Views:

Creating View by taking multiple base tables.

Ex:

CREATE VIEW EMP_DEPT_VIEW AS SELECT EMP.EMPNO, EMP.ENAME, DEPT.DEPTNO, DEPT.DNAME FROM EMP, DEPT WHERE EMP.DEPTNO=DEPT.DEPTNO

Syntax to create view based on another views: SQL SERVER enables users to create views based on another view. We can create view based on another view up to 32 levels

Syntax:

CREATE VIEW VIEWNAME [WITH ENCRYPTION] AS SELECT * FROM VIEWNAME [WHERE CONDITION] [WITH CHECK OPTION]

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Ex:

CREATE VIEW V5 AS SELECT * FROM V1 WHERE DEPTNO=10

Syntax to Drop the Views:

DROP VIEW VIEWNAME […N]

Ex: DROP VIEW V1, V2, V3, V4, V5

Indexes:

Indexes in SQL server is similar to index in text book... Indexes are used to improve the performance of queries.

INDEXES ARE GENERALLY CREATED FOR FOLLOWING COLUMNS1. Primary key column2. Foreign key column: frequently used in join conditions.3. Column which are frequently used in where clause4. Columns, which are used to retrieve the data in sorting order.

INDEXED CANNOT BE CREATED FOR FOLLOWING COLUMNS1. The columns which are not used frequently used in where

clause.2. Columns containing the duplicate and null values3. Columns containing images, binary information, and text

information.

TYPES OF INDEXES:

CLUSTERED INDEX NON-CLUSTERED INDEX

CLUSTERED INDEX: only one clustered index is allowed per table. The order of values in a table order of values in index is also same. When cluster index is created on table data is arranged in ascending order cluster index will occupy 5% of the table.

Syntax:

CREATE [UNIQUE] CLUSTERED INDEX INDEXNAME ON TABLENAME (COLUMN)

Ex: CREATE CLUSTERED INDEX CI ON EMP (EMPNO)

Note: If we want to maintain unique values in clustered/non clustered indexed column then specify UNIQUE keyword along with CLUSTERED INDEX/NONCLUSTERD INDEX

NONCLUSTERED INDEX: It is the default index created by the server the physical order of the data in the table is different from the order of the values in index. Max no. Of non-clustered indexed allowed for table is 249

Syntax:

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CREATE [UNIQUE] NONCLUSTERED INDEX INDEXNAME ON TABLENAME (COLUMN1…)

Ex:CREATE NONCLUSTERED INDEX NCI ON EMP (ENAME, SAL)

Ex: CREATE UNIQUE NONCLUSTERED INDEX UI ON DEPT (DNAME)

COMPOSITE INDEX: If a Unique NonClustered index is created on more than one column then that concept is called composite index.

CREATE UNIQUE NONCLUSTERED INDEX COI ON DEPT (DEPTNO, DNAME)

DEPTNO DNAME

10 SALES20 HR30 IR10 HR (Accepted)20 SALES (Accepted)30 IR (Repeated, Not accepted)

SP_HELPINDEX: This stored procedure is used to display the list of indexes, which have been placed on different columns of a specific table.

Ex: SP_HELPINDEX EMP

Syntax to drop the index:

DROP INDEX TABLENAME.INDEXNAME

Ex:

DROP INDEX DEPT.UI

Synonym:

It is a database object

It is a second or duplicate name which can be assigned to a table

It will not occupies any space, just it is a second name of the table

Trough synonyms we can impose securities i.e. we can hide actual table names

Syn: create synonym syn_name for <TN>

Ex: create synonym syn_1 for EMP

Retrieving data:

Syn: select*from syn_nameEx: select*from syn_1

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Dropping:

Syn: drop synonym <TN>Ex: drop synonym syn_1

RULES AND DEFAULTS:

CREATING DEFAULT: Default is one of the database objects used to declare default values globally.

Syntax:

CREATE DEFAULT DEFAULTNAME AS NUMERICVALUE/STRING VALUE

Ex:

CREATE DEFAULT D1 AS ‘UNKNOWN’

BINDING THE DEFAULT TO COLUMN:

Syntax:

SP_BINDDEFAULT DEFAULTNAME, ‘TABLENAME.COLUMN’

Ex:

SP_BINDDEFAULT D1, ‘DEPT.LOC’SP_BINDEFAULT D1, ‘EMP.ENAME’

INSERT INTO DEPT (DEPTNO, DNAME) VALUES (10,ACCOUNTING’)

SELECT * FROM DEPT WHERE DEPTNO =10DEPTNO DNAME LOC 10 ACCOUNTING UNKNOWN

INSERT INTO EMP (EMPNO, SAL, DEPTNO) VALUES (100, 5000,20)

SELECT EMPNO, ENAME, DEPTNO FROM EMP WHERE EMPNO =100EMPNO ENAME DEPTNO 100 UNKNOWN 20

UNBINDING THE DEFAULT FROM THE BINDING COLUMN:

Syntax:

SP_UNBINDEFAULT ‘TABLENAME...COLUMN’

SP_UNBINDEFAULT ‘ DEPT.LOC’SP_UNBINDEFAULT ‘ EMP.ENAME’

DROPPING THE DEFAULT:

Syntax:

DROP DEFAULT DEFAULTNAME

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DROP DEFAULT D1

CREATING RULES: Rule is just check constraint but it is placed on columns globally.

Syntax:

CREATE RULE RULENAME AS EXPRESSION

Ex:

CREATE RULE R1 AS @ X >=10 AND @ X <= 60

BINDING THE RULE:

SP_BINDEFAULT RULENAME, ‘ TABLE.COLUMN’

SP_BINDEFAULT R1, ‘DEPT.DEPTNO’

INSERT INTO DEPT (DEPTNO) VALUES (70)

ERROR

UNBINDING THE RULES:

SP_UNBIND RULE ‘DEPT.DEPTNO’

DROPPING THE RULES:

DROP RULE RULENAME

DROP RULE R1

TSQL Programs:

Variable: whose can be varied is known as a variable

Types:

1. Local variable: once we declared local variable then it can be used into single program

Ex: @x int

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2. Global variable: once we declared global variable then it can be used into many no. of programs

Ex: @@y int

Constant: whose value can’t be varied

Ex: 1, 2,3,4,5

Note: tsql programs also known as tsql batches, these are two types

1. Named batches

2. Unnamed batches

Structure:

DeclareDeclaration and initiation of variablesBeginBody of the programEnd

1. Declare:

User can declare variables according to the requirement of the batch and can assign initial values to variables

Ex: declare @x int Set @x=10

2. Begin:

It contains actual code i.e.

LogicExceptionsConditional statementsOutput

Output: print 'output'

3. End: Ending of the batch

WAP to display the word 'welcome to database'

BeginPrint 'welcome to database'End

WAP to calculate sum of two numbers

Declare @x int Set @x=20

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Declare @y int Set @y=10Declare @z intBeginSet @z=@x+@yPrint @zEnd

Conditional Statements:

1. If. Else:

Syn:

DeclareVariable declaration and initiationBeginIf condition OutputElseOutputEnd

WAP to find out greatest number among two numbers

Declare @x int Set @x=20Declare @y int Set @y=10BeginIf @x>@yPrint 'x is greatest'ElsePrint 'y is greatest'End

2. If. Elseif... Else:

Syn:

DeclareVariable declaration and initiationBeginIf conditionOutputElse if conditionOutputElseOutputEnd

WAP to find out greatest number among three numbers

Declare @x intSet @x=20

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Declare @y intSet @y=10Declare @z intSet @z=5BeginIf @x>@y and @x>@zPrint 'x is greatest'Else if @y>@x and @y>@zPrint 'y is greatest'ElsePrint 'z is greatest'End

3. While:

Syn:

DeclareVariable declaration and initiationWhile conditionBeginBody of the program End

WAP to display numbers from 1 to 10 with increment of 1

DECLARE @counter INTSET @counter=1WHILE @counter <= 10BEGINPRINT @counterSET @counter=@counter+1END

Cursors:

Cursor is a logical area, which is used to retrieve a particular nth record. Selecting a particular nth record is not possible through physical area (Table). In such situations one logical area (Cursor) we can create and then we can select a particular nth record. Cursors are used to store transaction information temporarily.

Types of Cursors:

1. STATIC CURSOR2. DYNAMIC CURSOR3. KEYSET CURSOR4. FORWARD_ONLY CURSOR

DEPT_TABLE:

DEPTNO DNAME LOC

10 SALES HYD20 HR CHE30 IR BAN40 A/C MUM

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Syntax:

Syntax to declare the Cursor:

DECLARE CURSORNAME CURSOR CURSORTYPE FOR SELECT * FROM TABLENAME

Syntax to open the Cursor:

OPEN CURSORNAME

Syntax to fetch the records from Cursor:

FETCH {FIRST/NEXT/PRIOR/LAST/ABSOLUTE N/RELATIVE N} FROM CURSORNAME

Syntax to close the Cursor:

CLOSE CURSORNAME

Syntax to de allocates the Cursor:

DEALLOCATE CURSORNAME

FIRST: Fetches first record from the cursor

NEXT: Fetches next record from the current position of the cursor

PRIOR: Fetches previous record from the current position of the cursor

LAST: Fetches last record from the cursor

ABSOLUTE N: Fetches nth record from the top of the cursor if n is positive fetches the nth record from bottom of the cursor if n is negative. Where n is an integer

RELATIVE N: Fetches nth next record from current position of the cursor if n is positive fetches nth previous record from the current position of the cursor if n is negative where n is an integer.

1. STATIC CURSOR:

This is the logical area in which dynamic updations not possible. If we want those updations in logical area we close the cursor and we need to reopen it.

1.

DECLARE SC CURSOR STATIC FOR SELECT * FROM DEPT

OPEN SC

FETCH FIRST FROM SC10 SALES HYD

UPDATE DEPT SET DEPTNO=15 WHERE DEPTNO=10

FETCH FIRST FROM SC

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10 SALES HYD

CLOSE SCOPEN SC

FETCH FIRST FROM SC15 SALES HYD

FETCH NEXT FROM SC20 HR CHE

FETCH PRIOR FROM SC15 SALES HYD

FETCH LAST FROMSC40 A/C MUM

FETCH ABSOLUTE 2 FROM SC20 HR CHE

FETCH ABSOLUTE –2 FROM SC30 IR BAN

FETCH FIRST FROM SC15 SALES HYDFETCH RELATIVE 2 FROM SC30 IR BAN

FETCH RELATIVE –2 FROM SC15 SALES HYD

CLOSE SCDEALLOCATE SC

2. DYNAMIC CURSOR:

This is the logical area in which dynamic updations possible. We need to close and reopen the cursor for the modified values

Ex:DECLARE DC CURSOR DYNAMIC FOR SELECT * FROM DEPT

OPEN SC

FETCH FIRST FROM DC15 SALES HYD


FETCH FIRST FROM DC10 SALES HYD

CLOSE DC DEALLOCATE DC

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Note: ABSOLUTE N will not be supported by the dynamic cursor because dynamic updations are possible.

3. KEYSET CURSOR:

This is the logical area, which is useful only when there is a primary key in the table. This logical area holds only Primary key column values. Based on the key column values in the logical area (Cursor) the rest column values are coming from physical area (Table).

Ex:

DECLARE KC CURSOR KEYSET FOR SELECT * FROM DEPT

OPEN KC

FETCH FIRST FROM KC10 SALES HYD

UPDATE DEPT SET LOC=’SRNAGAR’ WHERE LOC=’HYD’FETCH FIRST FROM KC10 SALES SRNAGAR


FETCH FIRST FROM KC0 NULL NULL

CLOSE KCOPEN KC

FETCH FIRST FROM KC15 SALES HYD

CLOSE KCDEALLOCATE KC

Note: Dynamic updations are not possible on key column of the keyset cursor, we have to close the cursor and we need to reopen it for the modified values.

4. FORWARD_ONLY CURSOR:

This is the most unused logical area because it supports only NEXT operation.

Ex:DECLARE FC CURSOR FORWARD_ONLY FOR SELECT * FROM DEPT

OPEN FC

FETCH FIRST FROM FCError Message

FETCH NEXT FROM FC15 SALES HYD

CLOSE SCDEALLOCATE FC

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NOTE:

If the cursor does not found any value in its searching process then it will display the corresponding column values.

1. BATCH TO FETCH MULTIPLE RECORDS FROM STATIC CURSOR

Step1: DECLARE SC CURSOR STATIC FOR SELECT * FROM DEPT

Step2:

DECLARE @N INTOPEN SCSET @N=2WHILE (@N<=4)BEGINFETCH ABSOLUTE @N FROM SCSET @N=@N+1END

Step3: CLOSE SCDEALLOCATE SC

OUTPUT:

DEPTNO DNAME LOC

20 HR CHE

DEPTNO DNAME LOC 30 IR BAN

DEPTNO DNAME LOC 40 A/C MUM

Stored Procedures:

It is a database object After successful compilation it will be stored into a precompiled programming unit

So that with out compilation we can use same stored procedure any number of times

User can get reusability

It is major part performance tuning

Used complete a task in database

Types:

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1. System stored procedures:

Ex:

sp_tablessp_helptable <TN>sp_helpdb <database name>sp_renamesp_addumpdevice

2. User stored procedure:

defined by the users explicitly

variable are known as "parameters"

parameters are two types

1. In :( default) used to pass the values

2. Output: used to get the values

Note: stored procedure can return multiple values through its output parameter

Syntax:

CREATE PROC [EDURE] PROCEDURENAME[@PARA 1 DATATYPE (SIZE)[=DEFAULT_VALUE][OUTPUT]@PARA 2 DATATYPE (SIZE)[=DEFAULT_VALUE][VALUE],….]

AS BEGINSELECT STATEMENTEND

Syntax to execute the user defined stored procedure:

EXEC [UTE] PROCEDURENAME [VALUE1, VALUE2…]

Drop:

Drop procedure pro_name

Programs:

Create a stored procedure to insert data into dept table

Create procedure insert_dept @dno int,@name varchar (20),@loc varchar (20)AsBeginInsert into dept (deptno, dname, loc) values (@dno, @name, @loc)End

Execution:

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Exec insert_dept 50,'csc','hyderabad'

Result:

Select*from dept

Create a stored procedure to update dname, loc according to the given deptno of dept table

Create procedure update_dept @dno int, @name varchar (20),@loc varchar (20)AsBeginUpdate dept set dname=@name,loc=@loc where deptno=@dnoEnd

Execution:

Exec update_dept 50,'eee','india'

Result:

Select*from dept

Note: The number of values supplied through EXEC statement must be equal to the number parameters.

Write a procedure to select the data from EMP table.

CREATE PROCEDURE P1 ASBEGINSELECT * FROM EMPEND

EXEC P1

Write a procedure to select the data from EMP table based on user supplied DEPTNO.

CREATE PROCEDURE P2 @X INTASBEGINSELECT * FROM EMP WHERE DEPTNO=@XEND

EXEC P2 20

Write a procedure to add two numbers

CREATE PROCEDURE P3 @A INT=10,@B INT=20ASBEGINDECLARE @C INTSET @C=@A+@BPRINT @C

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END

EXEC P3

Output: 30

EXEC P3 25, 45

Output: 70

Note: Server will give highest priority to the user supplied values rather than default values.

User Defined Functions :( UDF’S)

It is a database object

Used to complete calculations in database

It is like stored procedure after successful compilation it will stored into database as a pre compiled programming unit

User’s gets reusability facility i.e. without compilation users can go for execution

It contains only one parameter

In parameter: used to pass the values

1. Through return statement it can send value to the user

2. Udf’s can return single value with data type

Functions created by user are called user defined functions

Types of user defined functions:

1. SCALAR VALUED FUNCTIONS2. TABLE VALUED FUNCTIONS

1. Scalar valued functions: These functions will return a scalar value to the calling environmentSyntax: CREATE FUNCTION < FUNCTION_NAME> (@PARA 1 DATA TYPE ,

@ PARA 2 DATATYPE…)RETURNS <DATATYPE>ASBEGINDECLARE @VARIABLE DATATYPE------------------RETURN @VARIABLEEND

Syntax to execute the user defined function:

SELECT/PRINT DBO.FUNCTIONNAME (VALUE1, VALUE2…)

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Note: The number of values supplied through PRINT/SELECT statement must be equal to the number parameters.

Write a function to find the product of two numbers

CREATE FUNCTION F1 (@ A INT, @B INT) RETURNS INT ASBEGINDECLARE @ C INTSET @C = @A * @BRETURN @CEND

SELECT/PRINT DBO.F1 (3,5)

Write function to find the net salary of an employee read EMPNO though parameter and display the net to return value

CREATE FUNCTION F2 (@ VNO INT)RETURNS INTAS BEGIN

DECLARE @ VSAL INT, @VCOM INT, @NET INTSELECT @VSAL = SAL, @VCOM=COM

FROM EMP WHERE EMPNO =@VNOIF @ VCOM IS NULLBEGINPRINT ‘COMMISION IS NULL’SET @NET = @VSALENDELSEBEGINSET @ NET = @VSAL + @VCOMENDRETURN (@NET)END

PRINT/SELECT DBO.F2(22)

2. Table valued function: These functions will return entire table to the calling environment.

Syntax:CREATE FUNCTION <FUNCTION_NAME> (PARA 1 DATA TYPE ……….)RETURNS TABLE ASBEGIN<FUNCTION BODY>RETURN (SELECT STATEMENT)END

Write a function to return entire dept tableCREATE FUNCTION F3()RETURNS TABLEAS

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BEGINRETURN (SELECT * FROM DEPT)END

SELECT * FROM F3()

DEPT DNAME LOC

CREATE FUNCTION F4()RETURN TABLEAS BEGINRETURN(SELECT ENAME, DNAME FROM EMP, DEPT WHERE EMP.DEPTNO = DEPT.DEPTNO)END

SELECT * FROM F4()

ENAME DNAME SMITH RESEARCHMILLER ACCOUNTING

Create function to convert datetime data into char

Default datetime format: 'yyyy-mm-dd HH: MI: SS: MS’

2009-07-31 -- is it datetime data in sqlserver 2005?

No

CREATE FUNCTION DateOnly (@InDateTime date time)RETURNS varchar (10)ASBEGIN

DECLARE @MyOutput varchar (10)SET @MyOutput = CONVERT (varchar (10), @InDateTime, 101)RETURN @MyOutput

END

Note: Convert is inbuilt function used to convert data from one data type to another

To call our function, execute: SELECT dbo.DateOnly (GETDATE ())

Drop:

Syn:

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Drop function fun_name

TRIGGERS:

Two types of Triggers are there in SQLSERVER 2005, they are

1. DDL TRIGGERS: Can be created on database Servers and databases.

2. DML TRIGGERS: Can be created on Tables and Views.

DML Triggers:

DML triggers respond to user INSERT, UPDATE, DELETE operations against a table or a view. When a data modification event occurs, the trigger performs a set of actions defined within the trigger. Similar to stored procedures, triggers are defined in Transact-SQL and allow a full range of activities to be performed.

A DML trigger can be defined specifically as FOR UPDATE, FOR INSERT, FOR DELETE, or any combination of the three. UPDATE triggers respond to modifications against one or more columns within the table, INSERT triggers respond to new data being added to the database, and DELETE triggers respond to data being deleted from the database.

There are two types of DML triggers: AFTER and INSTEAD OF.

AFTER triggers are only allowed for tables, and they execute after the data modification has been completed against the table.

INSTEAD OF triggers execute instead of the original data modification and can be created for both tables and views.

DML triggers allow you to perform actions in response to data modifications in a table.For example, you can create a trigger that populates an audit table based on the operation performed, or perhaps use the trigger to decrement the value of a quantity. Although this ability to trigger actions automatically is a powerful feature, there are a few things to keep in mind before your use of triggers proliferates:

• Triggers can often become a hidden and hence forgotten problem. When troubleshootingPerformance or logical issues, DBAs can forget that triggers are executing in the background.Make sure that your use of triggers is “visible” in your data documentation.

• If you can ensure that all your data modifications flow through a stored procedure, I wouldstrongly recommend you perform all activities within the stored procedure, rather than use aTrigger. For example, if you need to update a quantity in a related table, after inserting a salesrecord; why not put this logic in the stored procedure instead? The advantages are manageability(One place to look) and supportability (one place to troubleshoot), when the Procedure needs modifications or performs unexpected actions.

• Always keep performance in mind and this means writing triggers that execute quickly.Long-running triggers can significantly slow down data modification operations. Take particularcare in putting triggers into databases with frequent data modifications.

• Non-logged updates do not cause a DML trigger to fire (for example WRITETEXT, TRUNCATETABLE and bulk insert operations).

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• Constraints usually run faster than a DML trigger, so if your business requirements can befulfilled by a constraint, use constraints instead. AFTER triggers run after the data modificationhas already occurred, so they cannot be used to prevent a constraint violation.

• Don’t allow result sets from a SELECT statement to be returned within your trigger. Mostapplications can’t consume these in an elegant fashion, and embedded queries can hurt theTrigger’s performance.

Parts of Trigger:

1. Triggering Statement2. Triggering Restriction3. Triggering Action

Note: Triggering Action is different from remaining parts, because Trigger fires implicitly whenever an event occurs against to the Triggering Condition.

Things to Observe:

When user creates an after Trigger on any table for INSERT operation then server arranges a temporary table “INSERTED” for holding recently inserted values.

When user creates an after Trigger on any table for DELETE operation then server arranges a temporary table “DELETED” for holding recently deleted values.

When user creates an after Trigger on any table for UPDATE operation then server arranges two temporary tables “INSERTED, DELETED” for holding old and new values of UPDATE operation.

Syntax of After Trigger:

CREATE TRIGGER TRIGGERNAME ON TABLE NAMEFOR/ AFTER {INSERT/ UPDATE/ DELETE} ASBEGIN SQL STATEMENTEND

Syntax for Instead of Trigger:

Create trigger <Trigger_name> on <TN> or <View_name> instead of INSERT OR UPDATE OR DELETE As Begin Body of the program End

Drop:

Syntax: Drop trigger <Trigger_name>

Retrieve list of Triggers on a Table:

Syn: sp_helptrigger <TN>

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Ex: sp_helptrigger EMP

To view the SQL behind a specific trigger

Syn: sp_helptext <Trigger_name>

Create a trigger for generate alert

Create trigger tri_emp on EMP after insertAsBeginPrint 'one row inserted'End

Result:

Insert into EMP (empno) values (1)

Create a trigger for copying data from Temp table to Original table

CREATE TRIGGER deleteorder_trigger ON ordersAFTER DELETEASBEGININSERT INTO orders_archive (order_id, order_date, cust_id)SELECT order_id, order_date, cust_id FROM DELETEDEnd

Note:

1. Create Orders, Orders_archive tables before running above program.2. Orders, Orders_archive tables contain same structure.3. DELETED is a temporary table

Ex:

CREATE TRIGGER vendor_trigger ON EMPAFTER INSERT, UPDATEASBEGINUPDATE EMP SET ename=Upper (ename)WHERE empno IN (SELECT empno FROM INSERTED)END

Instead of Trigger:

Ex:

CREATE TRIGGER T4 ON DEPT INSTEAD OF INSERT,UPDATE, DELETEASBEGINPRINT ‘THESE OPERATIONS ARE NOT ALLOWED’END

The above trigger fires automatically and shows a message THESE OPERATIONS ARE NOT ALLOWED, when user try to perform INSERT, UPDATE, DELETE operations on DEPT table.

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DDL TRIGGERS (2005 Triggers):

These triggers are fired when user performs DDL operations in the database and these triggers belong to database. It means we can define triggers on the current database.

Syntax:

CREATE TRIGGER TRIGGERNAME ON DATABASEFOR/ AFTER {DROP,/ALTER/ CREATE} ASBEGIN SQL STATEMENT.END

1.

USE PUBS

CREATE TRIGGER DROP_TRG ON DATABASE FOR DROP_TABLE ASBEGINPRINT ‘TABLE DROPPED’END

2.

USE PUBS

CREATE TRIGGER DROP_TRG ON DATABASE INSTEAD OF DROP_TABLE ASBEGINPRINT ‘U CANNOT DROP THE TABLE’END

DIFFERENCE BETWEEN ORACLE & SQL Server:

ORACLE

%TYPE data type

SQL Server

No equivalent

DESCRIPTION

The %TYPE data type of Oracle lets you create a variable and have that variable's data type be defined by a table or view column or a PL/SQL package variable.

There is no equivalent for Oracle's %TYPE datatype in T-SQL, but it can be simulated (not very conveniently though) using User Defined Data types (UDT). Here is an example:

EXEC sp_addtype 'MyType', 'smallint', NULL

CREATE TABLE MyTable (i MyType)

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CREATE PROC MyProcASBEGINDECLARE @i MyTypeEND

BEFORE triggers INSTEAD OF triggers Use INSTEAD OF trigger in SQL Server as an equivalent to

Oracle's BEFORE trigger.

For more information on INSTEAD OF triggers, see SQL Server Books Online

DECODE() function

CASE expression DECODE can be conveniently simulated using the T-SQL

CASE expression. Here's an example:

SELECT Sport, CASE SportWHEN 'Cricket' THEN 'England' WHEN 'Hockey' THEN 'India' WHEN 'Base Ball' THEN 'America' ELSE NULL END AS 'Originating Country'FROM Sports

DESCRIBE sp_help or sp_columns There are a lot of alternatives for Oracle's DESCRIBE, in SQL

Server. You could use the system stored procedure sp_help for detailed information about a table's columns and other properties.

If sp_help is providing you with too much information, then try the ODBC catalog stored procedure, sp_columns.

There are a bunch of other useful sp_help* stored procedures available in SQL Server. You can find more information about those in SQL Server Books Online.

If none of those procedures are suitable for your requirements, then you could query the system view INFORMATION_SCHEMA.COLUMNS, to get the desired information. You could wrap your code inside a stored procedure named DESCRIBE, if you wish.

As a last resort, you could even query system tables like sysobjects and syscolumns, but this is not a recommended approach.

DUAL table No equivalent

There is no DUAL table in SQL Server. In fact, you don't need one in SQL Server, as you can have a SELECT statement without a FROM clause.

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For example, consider the following SELECT statement in Oracle:

SELECT 'Something'FROM DUAL

In SQL Server, the same result can be obtained by the following command:

SELECT 'Something'

If you are porting some code from Oracle into SQL Server and if you don't want to remove all references to DUAL table, then just create a DUAL table in your database using the following commands:

CREATE TABLE DUAL(DUMMY varchar(1))

INSERT INTO DUAL (DUMMY) VALUES ('X')

INTERSECT operator

Not supported

Use EXISTS clause to generate the same result.

The following example illustrates the simulation of Oracle's INTERSECT operator:

SELECT OrderID, OrderDateFROM Orders OWHERE EXISTS(SELECT 1FROM RefundsTable RWHERE O.OrderID = R.OrderID)

MINUS operator Not supported

Use NOT EXISTS clause in your SELECT statement to generate the same result.

The following example illustrates the simulation of Oracle's MINUS operator:

SELECT OrderID, OrderDateFROM Orders OWHERE NOT EXISTS(SELECT 1FROM RefundsTable RWHERE O.OrderID = R.OrderID

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)

Nested tables Not supported

Oracle 8i and prior versions didn't support this feature and is introduced in Oracle 9i. This feature basically enables you to store a table, within a column. It is like having an array of records in your database columns.

SQL Server has no concept of nested tables.

As a workaround, You could store your sub-tables or child tables in the form of XML inside a char, nchar, varchar, nvarchar, text or ntext type column, and parse it as needed, at runtime. See OPENXML, sp_xml_preparedocument, sp_xml_removedocument in SQL Server 2000 Books Online.

Another possible workaround would be to store comma separated values (CSV).

Note that this is against the basic rules of normalization. Columns are nomore atomic, with nested tables.

From a design point of view, best thing to do would be, to create different tables for representing different entities and link them with primary and foreign key relationships. This will also make searching easier.

Packages Not supported

No equivalent in SQL Server for Oracle's Packages and Package variables concept

PL/SQL T-SQLPROGRAMMING Every database product implements and extends the standard

SQL. Oracle's implementation of SQL is called PL/SQL, while Microsoft's is called T-SQL (Transact-SQL)

Row level security No equivalent

Though there is no inbuilt support in SQL Server for row level permissions, you can implement it using view and system functions.

For more information and a working example, read this article:

Implementing row level permissions/security in SQL Server databases

rownum pseudo column

No equivalent

Though there is no rownum or rowid in SQL Server, there are several ways in which a row number can be generated.

For some examples, read this article:

Q186133 INF: How to Dynamically Number Rows in a Select

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http://vyaskn.tripod.com/row_level_security_in_sql_server_databases.htm

http://vyaskn.tripod.com/row_level_security_in_sql_server_databases.htm

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Statement

SELECT...FOR UPDATE

UPDLOCK hint

Use the locking hint UPDLOCK in your SELECT statement.

See SQL Server Books Online for more information.

Sequences IDENTITY

It is much simpler in SQL Server to generate a sequence value for a primary key or a non-key column.

You just need to turn on the IDENTITY property of column. IDENTITY property can be set to columns of the following data types: tinyint, smallint, int, bigint, decimal, numeric

Try this example to see how it works:

CREATE TABLE foo(i int IDENTITY(1, 1)j int)

INSERT INTO foo (j) VALUES (911)INSERT INTO foo (j) VALUES (999)

SQL *Plus Query Analyzer/SSMS For connecting to SQL Server and executing queries and

modifying data, use the built-in Query Analyzer. It is much more powerful and friendlier than Oracle's SQL *Plus

START WITH...CONNECT BY clause

No equivalent

Though there's no direct equivalent in T-SQL for Oracle's START WITH...CONNECT BY, there are several ways and efficient techniques for processing and querying hierarcical data.

For more information, read this article:

Working with hierarchical data in SQL Server databases

Synonym Views

You can simulate Oracle Synonyms in SQL Server using Views. For example, the following creates a view that returns the OrderID and OrderDate from Orders table.

CREATE VIEW vOrdersASSELECT OrderID, OrderDateFROM Orders

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http://vyaskn.tripod.com/hierarchies_in_sql_server_databases.htm



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Now you can select data from the view, using the following SELECT statement:

SELECT * FROM vOrders

The following example will create a view which is equivalent to Oracles TABS synonym or USER_TABLES data dictionary view (For simplicity, I am only including the table name in the view definition):

CREATE VIEW TABSASSELECT name AS table_nameFROM sysobjectsWHERE type = 'U'

Now you can execute the following SELECT statement to return all user table names:

SELECT table_name FROM TABS

T-SQL Enhancements in 2008:

Every new version of SQL Server comes with several T-SQL features and enhancements.SQL Server 2008 is no exception. In the newest version of SQL Server, Microsoft has responded to developer requests in a big way. SQL Server 2008 supports brand new developer convenience features like single statement declaration and initialization, new data types to manipulate and query date-based and spatial data, new statements like MERGE that add much needed functionality to T-SQL and a whole lot more. Once you’ve made the move to SQL Server 2008, you’ll undoubtedly want to take advantage of the new features and functionality to solve common problems.

1. Separate Variable Declaration and Initialization

The first of these new features is single statement variable declaration and initialization. In the past, developers had to declare new variables in one or more DECLARE statements and assign values to the variables in one or more SET or SELECT statements as shown in below Listing.

DECLARE @x int, @y int, @z intSET @x=1SET @y=2SET @z=3

With single statement declaration and initialization, you can combine these two steps into a single step as shown in below Listing

DECLARE @x int =1,@y int=2, @z int =3

2. Calculating and Assigning Values with C-Style Assignment

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T-SQL has further improved with the addition of several C-Style assignment operators.

Operator Description+= Addition with assignment, or string

concatenation with assignment -= Subtraction with assignment *= Multiplication with assignment/= Division with assignment%= Modulo with assignment

Ex:

DECLARE @x int=4, @y int=25, @s1 varchar(20)=’Sql’SET @x *= @ySET @s1+= ‘SERVER’

SELECT @x, @s1

3. NEW INSERT STATEMENT

SYNTAX:

INSERT INTO TABLE_NAME VALUES(VALUE1, VALUE2,……), (VALUE1, VALUE2,…..),(VALUE1,VALU2,……..)

EX:

INSERT INTO EMPVALUES(11,’RAM’, 30000, 10),(22,’RAJ’, 20000, 20)

Like in SQL Server 2005 we need not to write multiple INSERT statements for multiple records. With in single INSERT statement we can insert multiple records into the table at a time

4. MERGE Statement

It is one of the DML statement placed newly in SQL Server 2008

Merge Statement is a combination statement that can perform INSERT, UPDATE, DELETE statements based on whether rows that match the selection criteria exist in the target table or not.

This Merge statement takes Target and Source Tables, When Source rows are matched with Target it will update the rows of source table into target table otherwise it will insert the rows of source table into target table. Always merge statement takes a temp table as its source

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and base table as its target table. Using this Merge statement we can combine the rows of a source table to target table.

Syntax:

MERGE Target_Table as targetUSING Source_table as sourceON conditionWHEN MATCHED THENUPDATESET column=source.column,……….. WHEN TARGET NOT MATCHED THENINSERT VALUES (source.column1, source.column2,)

4. New Data Types In 2008

SQL Server 2008 provides new data types that support storage, manipulation and querying of new forms of data. Some, like the date data type which stores a simple date with out the time component. Others like the geometry data type, which allows storage and querying of spatial data, have only recently addressed.

Date and Time Data Types

SQL Server supports four brand new date and time data types, which includes

1. date2. time3. datetime24. datetimeoffset

The date data type finally allows us to store date only without the time component. It can also store a much larger range of dates than datetime and smalldatetime data types.

The date data type can handle dates from January 1, 1 CE (0001-01-01) to December 31, 9999 CE (9999-12-31)

Ex:

DECLARE @d1 date=’0014-08-19’DECLARE @d2 date=’1983-02-26’SELECT @d1 as DATE1,@d2 as DATE2DATEDIFF (YEAR, @d1, @d2) as YEARDIFFERENCE

In contrast to the date data type, the time data type lets you to store time only data.The range for the time data type is defined on 24 hour clock, from 00:00:00.0000000 through 23:59:59.9999999 with user defined fractional second precision of up to seven digits.

Ex:

DECLARE @start_time time (1) =’06:25:19.1’ --1 digit fractional precision

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DECLARE @end_time time=’18:25:19.1234567’ --default fractional precision

SELECT @start_time as STARTTIME, @end_time as ENDTIMEDATEADD (HOUR, 6, @start_time) as STARTTIMEPLUS,DATEDIFF (HOUR,@start_time,@end_time) as ENDSTARTDIFF

The cleverly named datetime2 data type is an extension to the standard datetime data type. The datetime2 combines the benefits of the new date and time data types, giving you the wide date range of the date data type and the greater fractional second precision of the time data type.

Ex:

DECLARE @start_dt2 datetime2=’1972-07-06T07:13:28.8235670’DECLARE @end_dt2 datetime2=’2009-12-14T03:14:13.2349872’

SELECT @start_dt2 as start_dt2, @end_dt2 as end_dt2

The new datetimeoffset data type builds on datetime2 by adding the ability to store offsets relative to the International Telecommunication Union(ITU) standard for Coordinated Universal Time(UTC) with your date and time data type.

5. The Hierarchyid Data Type

The hierarchyid data type offers to represent hierarchical data in the database. This new data type offers built-in support for representing your hierarchical data using one of the simplest models available: materialized paths

Hierarchyid Data Type Methods

Method DescriptionGetAncestor(n) Retrieves the nth ancestor of the hierarchyid

node instanceGetDescendent(n) Retrieves the nth descendent of the hierarchyid

node instanceGetLevel() Gets the level of the hierarchyid node instance

in the hierarchyGetRoot() Gets the root node of the hierarchyid instance

in the hierarchyIsDescendent(node) Returns 1 if a specified node is descendent Parse(String) Converts the given canonical string, in forward

slash- separated format to a hierarchyid path.Reparent(old_root,new_root) Reparents a node by moving nodes from

old_root to new_rootToString() Converts a hierarchyid instance to a canonical

forward slash-separated string representation

5. The Spatial Data Type

SQL Server 2008 includes two new data types for storing, querying, and manipulating spatial data.

Geometry Geography

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Geometry data type is designed to represent flat-earth, or Euclidean, spatial data.

Geography data type supports round earth or ellipsoidal, spatial data.

QUERIES:

1. Display the dept information from department table.Select * from DEPT;

2. Display the details of all employees.Select * from EMP;

3. Display the name and job for all employees.Select ename, job from EMP;

4. Display name and salary for all employees.Select ename, sal from EMP;

5. Display employee number and total salary for each employee.Select empno, sal+comm from EMP;

6. Display the names of all employees who are working in department number 10.Select ename from EMP where deptno=10;

7. Display the names of all employees working as clerks and drawing a salary more than 3000.select ename from EMP where job=’CLERK’ and sal>3000;

8. Display employee number and names for employees who earn commission.Select empno, ename from EMP where comm is not null and comm>0;

9. Display names of employees who do not earn any commission.Select empno, ename from EMP where comm is null and comm=0;

10. Display the names of employees who are working as clerk, salesman or analyst and drawing a salary more than 3000.Select ename from EMP where (job=’CLERK’ or job=’SALESMAN’ or job=’ANALYST’) and sal>3000; (Or)Select ename from EMP where job in (‘CLERK’,’SALESMAN’,’ANALYST’) and sal>3000;

11. Display the names of employees who are working in the company for the past 5 years.Select ename from EMP where sysdate-hiredate>5*365;

12. Display the list of employees who have joined the company before 30th June 90 or after 31st dec 90.Select * from EMP where hiredate between ‘30-jun-1990’ and ‘31-dec-1990’;

13. Display the names of employees working in department number 10 or 20 or 40 or employees working as clerks, salesman or analyst.

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Select ename from EMP where deptno in (10, 20, 40) or job in (‘CLERK’,’SALESMAN’,’ANALYST’);

14. Display the names of employees whose name starts with alphabet S.Select ename from EMP where ename like ‘S%’;

15. Display employee names for employees whose name ends with alphabet.Select ename from EMP where ename like ‘%S’;

16. Display the names of employees whose names have second alphabet A in their names.Select ename from EMP where ename like ‘_S%’;

17. Display the names of employees whose name is exactly five characters in length.Select ename from EMP where length (ename) =5;(Or)Select ename from EMP where ename like '_____';

18. Display the names of employees who are not working as SALESMAN or CLERK or ANALYST.Select ename from EMP where job not in (‘CLERK’,’SALESMAN’,’ANALYST’);

19. Display the total number of employees working in the company.Select count (*) from EMP;

20. Display the maximum salary from EMP table.Select max (sal) from EMP;

21. Display the minimum salary from EMP table.Select min (sal) from EMP;

22. Display the average salary from EMP table.Select avg (sal) from EMP;

23. Display the maximum salary being paid to CLERK.select max (sal) from EMP where job=’CLERK’;

24. Display the maximum salary being paid in dept no 20.Select max (sal) from EMP where deptno=20;

25. Display the min Sal being paid to any SALESMAN.select min (sal) from EMP where job=’SALESMAN’;

26. Display the average salary drawn by managers.select avg (sal) from EMP where job=’MANAGER’;

27. Display the names of employees in order of salary i.e. the name of the employee earning lowest salary should appear first.Select ename from EMP order by sal;

28. Display the names of employees in descending order of salary.Select ename from EMP order by sal desc;

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29. Display the details from EMP table in order of EMP name.Select ename from EMP order by ename;

30. Display empno, ename, deptno, and sal. Sort the output first based on name and within name by deptno and within deptno by Sal;Select * from EMP order by ename, deptno, sal;

31. Display name, Sal, hra, pf, da, total Sal for each employee. The output should be in the order of total Sal, hra 15% of Sal, da 10% of sal, pf 5% of sal total salary will be (sal*hra*da)-pf.select ename,sal,sal*15/100 HRA, sal*5/100 PF, sal*10/100 DA,sal+sal*15/100-sal*5/100+sal*10/100 TOTAL_SALARY from emp

32. Display dept numbers and total number of employees within each group.select deptno,count(*) from emp group by deptno;

33. Display the various jobs and total number of employees with each job group.select job, count(*) from emp group by job;

34. Display department numbers and total salary for each department.select deptno, sum(sal) from emp group by deptno;

35. Display department numbers and maximum salary for each department.select deptno, max(sal),min(sal) from emp group by deptno;

36. Display the various jobs and total salary for each job.select job, sum(sal) from emp group by job;

37. Display each job along with minimum sal being paid in each job group.select job, min(sal) from emp group by job;

38. Display the department numbers with more than three employees in each dept.select deptno, count(*) from emp group by deptno having count(*)>3;

39. Display the various jobs along with total sal for each of the jobs where total sal is greater than 40000.select job, sum(sal) from emp group by job having sum(sal)>40000;

40. Display the various jobs along with total number of employees in each job. The output should contain only those jobs with more than three employees.select job, count(*) from emp group by job having count(*)>3;

41. Display the name of emp who earns highest sal.select ename from emp where sal=(select max(sal) from emp);

42. Display the employee number and name of employee working as CLERK and earning highest salary among CLERKS.select empno, ename from emp where job='CLERK' and sal=(select max(sal) from emp where job='CLERK');

43. Display the names of the salesman who earns a salary more than the highest salary of any clerk.

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select ename from emp where job=’SALESMAN’ and sal > (select max(sal) from emp where job='CLERK');

44. Display the names of clerks who earn salary more than that of James of that of sal lesser than that of Scott.select ename from emp where job='CLERK' and sal<(select sal from emp where ename='SCOTT') and sal>(select sal from emp where ename='JAMES');

45. Display the names of employees who earn a Sal more than that of James or that of salary greater than that of Scott.select ename from emp where sal < (select sal from emp where ename='SCOTT') and sal > (select sal from emp where ename='JAMES');

46. Display the names of the employees who earn highest salary in their respective departments.select * from emp e where sal =(select max(sal) from emp where deptno=e.deptno)

47. Display the names of employees who earn highest salaries in their respective job groups.select * from emp e where sal in(select max(sal) from emp group by job having e.job=job)

48. Display the employee names who are working in accountings dept.select ename from emp where deptno =(select deptno from dept where dname=”ACCOUNTING”);(or)select ename from emp where deptno in (select deptno from dept where dname=”ACCOUNTING”);

49. Display the employee names who are working in Chicago.select ename from emp where deptno =(select deptno from dept where loc=’CHICAGO’);

50. Display the job groups having total salary greater then the maximum salary for managers.select job, sum(sal) from emp group by job having sum(sal) >(select max(sal) from emp where job='MANAGER');

51. Display the names of employees in Upper case.select upper(ename) from emp;

52. Display the names of employees in lower case.select lower(ename) from emp;

53. Replace every occurrence of alphabet A with B in the string Allen’s (user translate function).select replace('Allens','A','b') from dual;

54. Display the information from EMP table. Wherever job ‘manager’ is found it should be displayed as boss(replace function).select empno, ename, replace(job, 'MANAGER', 'Boss') JOB from emp;

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55. Display empno, ename, deptno from EMP table. Instead of display department numbers display the related department name (use decode function).select e.empno, e.ename, d.dname from emp e,dept d where e.deptno = d.deptno;

56. Display the common jobs from department number 10 and 20.select job from emp where deptno=10 and job in(select job from emp where deptno=20);(or)select job from emp where deptno=10 intersect select job from emp where deptno=20;

57. Display the jobs found in department number 10 and 20 eliminate duplicate jobs.select distinct(job) from emp where deptno=10 and job in(select job from emp where deptno=20);(or)select job from emp where deptno=10 intersect select job from emp where deptno=20;

58. Display the jobs which are unique to dept no 10.select job from emp where deptno=10 minus select job from emp where deptno!=10;(or)select job from emp where deptno = 10 and job not in (select job from emp where deptno<>10);

59. Display the details of those who do not have any person working under them.select empno from emp where empno not in (select mgr from emp where mgr is not null);

60. Display the details of employees who are in sales dept and grade is 3.select * from emp where sal>=(select losal from salgrade where grade=3) and sal<=(select hisal from salgrade where grade=3) and deptno=(select deptno from dept where dname='SALES');

61. Display those who are not managers and who are managers any one.select * from emp where empno in(select mgr from emp) unionselect * from emp where empno not in(select mgr from emp where mgr is not null);

62. Display those employees whose name contains not less than 4 chars.Select * from emp where length(ename)>4;

63. Display those departments whose name start with ‘S’ while location name end with ‘O’.select * from dept where dname like 'S%' and loc like '%O';

64. Display those employees whose manager name is JONES.select * from emp where mgr=(select empno from emp where ename='JONES');

65. Display those employees whose salary is more than 3000 after giving 20% increment.

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select * from emp where sal*120/100 > 3000;(or)select * from emp where sal+sal*20/100 > 3000;

66. Display all employees with there dept name.select ename, dname from emp e, dept d where e.deptno = d.deptno;

67. Display ename who are working in sales dept.select empno, ename from emp where deptno=(select deptno from dept where dname='SALES');

68. Display employee name, deptname, salary and comm. for those Sal in between 2000 to 5000 while location is Chicago.select empno,ename,deptno from emp where deptno=(select deptno from dept where loc='CHICAGO') and sal between 2000 and 5000;

69. Display those employees whose salary greater than his manager salary.select * from emp e where sal>(select sal from emp where empno=e.mgr);

70. Display those employees who are working in the same dept where his manager is working.select * from emp e where deptno = (select deptno from emp where empno=e.mgr);

71. Display those employees who are not working under any manger.select * from emp where mgr is null or empno=mgr;

72. Display grade and employees name for the dept no 10 or 30 but grade is not 4, while joined the company before 31-dec-82.select empno,ename,sal,deptno,hiredate,grade from emp e,salgrade s where e.sal>=s.losal and e.sal<=s.hisal and deptno in(10,30) and grade<>4 and hiredate<'01-dec-1981';

73. Update the salary of each employee by 10% increments that are not eligible for commission.update emp set sal=sal+(sal*10/100) where comm is null;

74. Delete those employees who joined the company before 31-dec-82 while there dept location is ‘NEW YORK’ or ‘CHICAGO’.delete from emp where hiredate<'31-dec-1982' and deptno in(select deptno from dept where loc in('NEW YORK','CHICAGO'));

75. Display employee name, job, deptname, location for all who are working as managers.select ename,job,dname,loc from emp e, dept d where e.deptno=d.deptno and empno in (select mgr from emp);

76. Display those employees whose manager names is Jones, and also display there manager name.select e.empno, e.ename, m.ename MANAGER from emp e, emp m where e.mgr=m.empno and m.ename='JONES';

77. Display name and salary of ford if his Sal is equal to high Sal of his grade.

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select ename,sal from emp e where ename='FORD' and sal=(select hisal from salgrade where grade=(select grade from salgrade where e.sal>=losal and e.sal<=hisal));

78. Display employee name, his job, his dept name, his manager name, his grade and make out of an under department wise.select d.deptno, e.ename, e.job, d.dname, m.ename, s.grade from emp e, emp m, dept d, salgrade s where e.deptno=d.deptno and e.sal between s.losal and s.hisal and e.mgr=m.empno order by e.deptno;

79. List out all the employees name, job, and salary grade and department name for every one in the company except ‘CLERK’. Sort on salary display the highest salary.select empno, ename, sal, dname, grade from emp e, dept d, salgrade s where e.deptno=d.deptno and e.sal between s.losal and s.hisal and e.job<>'CLERK' order by sal;

80. Display employee name, his job and his manager. Display also employees who are without manager.select e.ename, e.job, m.ename Manager from emp e,emp m where e.mgr=m.empno union select ename,job,'no manager' from emp where mgr is null;

81. Find out the top 5 earner of company.select * from emp e where 5>(select count(*) from emp where sal>e.sal) order by sal desc;

82. Display the name of those employees who are getting highest salary.select empno,ename,sal from emp where sal=(select max(sal) from emp);

83. Display those employees whose salary is equal to average of maximum and minimum.select * from emp where sal=(select (max(sal)+min(sal))/2 from emp);

84. Display count of employees in each department where count greater than 3.select deptno, count(*) from emp group by deptno having count(*)>3;

85. Display dname where at least 3 are working and display only dname.select dname from dept where deptno in(select deptno from emp group by deptno having count(*)>3);

86. Display name of those managers name whose salary is more than average salary of company.select ename, sal from emp where empno in(select mgr from emp) and sal > (select avg(sal) from emp);

87. Display those managers name whose salary is more than an average salary of his employees.select ename, sal from emp e where empno in(select mgr from emp) and e.sal>(select avg(sal) from emp where mgr=e.empno);

88. Find out the last 5(least) earner of the company?

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select * from emp e where 5>(select count(*) from emp where sal<e.sal) order by sal;

89. Find out the number of employees whose salary is greater than there manager salary?select count(*) from emp e where sal>(select sal from emp where empno=e.mgr);

90. Display those manager who are not working under president but they are working under any other manager?select * from emp e where mgr in(select empno from emp where ename<>'KING');

91. Delete those department where no employee working?delete from dept d where 0=(select count(*) from emp where deptno=d.deptno);

92. Delete those records from EMP table whose deptno not available in dept table?delete from emp where deptno not in(select deptno from dept);

93. Display those earners whose salary is out of the grade available in Sal grade table?select * from emp where sal<(select min(losal) from salgrade) or sal>(select max(hisal) from salgrade);

94. Display employee name, Sal, comm. and whose net pay is greater than any other in the company?Select ename, sal, comm from emp where sal+sal*15/100-sal*5/100 +sal*10/100 = (select max(sal+sal*15/100-sal*5/100+sal*10/100) from emp);

95. Display those employees who are working in sales or research?select * from emp where deptno in(select deptno from dept where dname in('SALES','RESEARCH'));

96. Display the grade of Jones?select grade from salgrade where losal<=(select(sal) from emp where ename='JONES') and hisal>=(select(sal) from emp where ename='JONES');

97. Delete those records where no of employee in a particular department is less than 3?delete from emp where deptno in(select deptno from emp group by deptno having count(*)>3);

98. Display the department name the no of characters of which is equal to no of employees in any other department?Select dname from dept where len (dname) in (select count(*) from emp group by deptno);

99. Display those employees who are working as manager?select * from emp where empno in(select mgr from emp);

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100. Count the no of employees who are working as manager (use set operation)?select count(*) from emp where empno in(select mgr from emp);

101. Display the name of then dept those employees who joined the company on the same date?select empno,ename,hiredate,deptno from emp e where hiredate in (select hiredate from emp where empno<>e.empno);

102. Display the manager who is having maximum number of employees working under him?Select mgr from emp group by mgr having count(*)=(select max(count(mgr)) from emp group by mgr);

103. Produce the output of the EMP table “EMPLOYEE_AND_JOB” for ename and job?select * from EMPLOYEE_AND_JOB;

104. Print the details of all the employees who are sub ordinate to Blake.Select * from emp where mgr=(select empno from emp where ename='BLAKE');

105. Display those who working as manager using co related sub query.Select * from emp where empno in(select mgr from emp);

106. Display those employees whose manger name is Jones and also with his manager name.Select * from emp where mgr=(select empno from emp where ename='JONES') union select * from emp where empno=(select mgr from emp where ename='JONES');

107. Find out how many mangers are there with out listing them.Select count (*) from EMP where empno in (select mgr from EMP);

108. Check whether all employees number are indeed unique.select count(empno),count(distinct(empno)) from emp having count(empno)=(count(distinct(empno)));

109. List out the lowest paid employees working for each manager, exclude any groups where min sal is less than 1000 sort the output by sal.select e.ename,e.mgr,e.sal from emp e where sal in(select min(sal) from emp where mgr=e.mgr) and e.sal>1000 order by sal;

110. find out the all employees who joined the company before their manager.Select * from emp e where hiredate<(select hiredate from emp where empno=e.mgr);

111. list out the all employees by name and number along with their manager’s name and number also display ‘No Manager’ who has no manager.select e.empno,e.ename,m.empno Manager,m.ename ManagerName from emp e,emp m where e.mgr=m.empnounion select empno,ename,mgr,'No Manager' from emp where mgr is null;

112. find out the employees who earned the highest Sal in each job typed sort in descending Sal order.

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select * from emp e where sal =(select max(sal) from emp where job=e.job);

113. find out the employees who earned the min Sal for their job in ascending order.select * from emp e where sal =(select min(sal) from emp where job=e.job) order by sal;

114. find out the most recently hired employees in each dept order by hire dateselect * from emp order by deptno, hiredate desc;

115. display ename, sal and deptno for each employee who earn a Sal greater than the avg of their department order by deptnoselect ename,sal,deptno from emp e where sal>(select avg(sal) from emp where deptno=e.deptno) order by deptno;

116. display the department where there are no employeesselect deptno,dname from dept where deptno not in(select distinct(deptno) from emp);

117. display the dept no with highest annual remuneration bill as compensation.select deptno,sum(sal) from emp group by deptno having sum(sal) = (select max(sum(sal)) from emp group by deptno);

118. display avg sal figure for the deptselect deptno,avg(sal) from emp group by deptno;

119. Write a query of display against the row of the most recently hired employee. display ename hire date and column max date showing.select empno,hiredate from emp where hiredate=(select max (hiredate) from emp);

120. display employees who can earn more than lowest Sal in dept no 30select * from emp where sal>(select min(sal) from emp where deptno=30);

121. find employees who can earn more than every employees in dept no 30select * from emp where sal>(select max(sal) from emp where deptno=30);select * from emp where sal>all(select sal from emp where deptno=30);

122. find all dept’s which have more than 3 employeesselect deptno from emp group by deptno having count(*)>3;

123. Create a copy of emp table.Create table emp1 as select * from emp;

124. Select ename if ename exists more than once.select distinct(ename) from emp e where ename in(select ename from emp where e.empno<>empno);

125. display all enames in reverse order.select ename from emp order by ename desc;

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126. List out the employees ename, sal, PF from empSelect ename,sal,sal*15/100 PF from emp;

127. Create table emp with only one column empnoCreate table emp (empno number(5));

128. Add this column to emp table ename Varchar(20).alter table emp add ename varchar2(20) not null;

129. OOPS! I forgot to give the primary key constraint. Add it now.alter table emp add constraint emp_empno primary key (empno);

130. Now increase the length of ename column to 30 characters.alter table emp modify ename varchar(30);

131. Add salary column to emp table.alter table emp add sal numeric(7,2);

132. I want to give a validation saying that sal cannot be greater 10,000(note give a name to this column).alter table emp add constraint emp_sal_check check (sal<10000);

133. Add column called as mgr to your emp table.Alter table emp add mgr numeric (5);

134. Oh! This column should be related to empno. Give a command to add this constraintAlter table emp add constraint emp_mgr foreign key(empno);

135. Add dept no column to your emp tableAlter table emp add deptno numeric (3);

136. This dept no column should be related to deptno column of dept tableAlter table emp1 add constraint emp1_deptno foreign key (deptno) references dept (deptno);

137. Create table called as new emp. Using single command create this table as well as to get data into this table (use create table as)Select*into newemp from EMP;

138. Create table called as newemp. This table should contain only empno,ename, dnamecreate table newemp as select empno,ename,dname from emp e , dept d where e.deptno=d.deptno;

139. Provide a commission to employees who are not earning any commission.update emp set comm=300 where comm is null;

140. If any employee has commission his commission should be incremented by 10% of his salary.update emp set comm=comm*10/100 where comm is not null;

141. Display employee name and department name for each employee.select ename,dname from emp e, dept d where e.deptno=d.deptno;

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142. Display employee number, name and location of the department in which he is working.Select empno, ename, loc from emp e, dept d where e.deptno=d.deptno;

143. Display employee name and his manager name.Select e.ename, m.ename from emp e, emp m where e.mgr=m.empno;

144. Display the department name along with total salary in each department.Select deptno, sum(sal) from emp group by deptno;

145. Display the department name and total number of employees in each department.select deptno,count(*) from emp group by deptno;

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