8/14/2019 SQL - 2071B 09

1/19

Module 9: Introductionto Programming Objects

8/14/2019 SQL - 2071B 09

2/19

Overview

Displaying the Text of a ProgrammingObject

Introduction to Views

Advantages of Views

Creating Views

Introduction to Stored Procedures

Introduction to Triggers

Introduction to User-defined Functions

8/14/2019 SQL - 2071B 09

3/19

Displaying the Text of aProgramming Object

EXEC sp_helptext [@objectname = ]name

Not Every Programming Object HasAssociated Text

USE library

EXEC sp_helptext 'dbo.OverdueView'GO

8/14/2019 SQL - 2071B 09

4/19

Introduction to Views

TitleViewTitleView

title author

Last of the MohicansThe Village Watch-TowerPoems

James Fenimore CooperKate Douglas WigginWilfred Owen

titletitle

title_no title author synopsis

123

Last of the MohicansThe Village Watch-TowerPoems

James Fenimore CooperKate Douglas WigginWilfred Owen

~~~~~~~~~

Users ViewUsers View

USE library

GO

CREATE VIEW dbo.TitleView

AS

SELECT title, author

FROM title

GO

8/14/2019 SQL - 2071B 09

5/19

Advantages of Views

Focus the Data for Users

Focus on important or appropriate dataonly

Limit access to sensitive data

Mask Database Complexity

Hide complex database design

Simplify complex queries, includingdistributed queries to heterogeneousdata

Simplify Management of UserPermissions

Or anize Data for Ex ort to Other

8/14/2019 SQL - 2071B 09

6/19

Creating Views

Defining Views

Restrictions on Creating Views

Example: Viewing Information fromMultiple Tables

8/14/2019 SQL - 2071B 09

7/19

Defining Views

USE library

GO

CREATE VIEW dbo.UnpaidFinesView (Member, TotalUnpaidFines)

AS

SELECT member_no, (sum(fine_assessed-fine_paid))

FROM loanhistGROUP BY member_no

HAVING SUM(fine_assessed-fine_paid) > 0

GO

SELECT *

FROM UnpaidFinesView

GO

Example 1: Creating a View

Example 2: Querying a View

8/14/2019 SQL - 2071B 09

8/19

Restrictions on Creating Views

Can Reference a Maximum of 1024Columns

Cannot Include COMPUTE or COMPUTE

BY clauses

Cannot Include ORDER BY Clause,Unless Used in Conjunction with a TOPClause

Cannot Include the INTO Keyword

Cannot Reference a Temporary Table

Must Be Expressed as a Single

Transact-SQL Batch

8/14/2019 SQL - 2071B 09

9/19

lastnamelastname

Thomas

Funk

firstnamefirstname

Gary

Frank

Birth DateBirth Date

92.01.16

84.01.18

member_nomember_no12

13

adult_noadult_no11

6

birth_datebirth_date1992-01-16 00:00:00.0001984-01-18 00:00:00.000

Example: Viewing Information fromMultiple Tables

membe

r

juvenile

BirthdayView

USE library

GO

CREATE VIEW dbo.birthdayview

(lastname, firstname, birthday)

AS

SELECT lastname, firstname,CONVERT(char(8), birth_date, 2)

FROM member

INNER JOIN juvenile

ON member.member_no = juvenile.member_no

GO

member_nomember_no11

12

13

14

lastnamelastnameThomas

Thomas

Funk

Rudd

firstnamefirstnameGary

Clair

Frank

Clair

middleinitialmiddleinitial~~~

~~~

~~~

~~~

photographphotograph~~~

~~~

~~~

~~~

8/14/2019 SQL - 2071B 09

10/19

Defining Stored Procedures

Advantages of Using StoredProcedures

Introduction to Stored Procedures

8/14/2019 SQL - 2071B 09

11/19

Defining Stored Procedures

A Stored Procedure Is a PrecompiledCollection of Transact-SQL Statements

A Stored Procedure Encapsulates

Repetitive Tasks Stored Procedures Can:

Contain statements that performoperations

Accept input parameters

Return status value to indicate successor failure

Return multiple output parameters

8/14/2019 SQL - 2071B 09

12/19

Advantages of Using StoredProcedures

Share Application Logic

Shield Database Schema Details

Provide Security Mechanisms Improve Performance

Reduce Network Traffic

8/14/2019 SQL - 2071B 09

13/19

Introduction to Triggers

A Trigger Is a Special Type of StoredProcedure

A Trigger Is:

Associated with a table

Invoked automatically

Not called directly

Treated as part of the transaction thatfired it

8/14/2019 SQL - 2071B 09

14/19

Introduction to User-definedFunctions

What Is a User-defined Function?

Creating a User-defined Function

8/14/2019 SQL - 2071B 09

15/19

What Is a User-defined Function?

Scalar Functions

Similar to a built-in function

Returns a single data value built by a series of

statements

Multi-Statement Table-valued Functions

Content like a stored procedure

Referenced like a view

In-line Table-valued Functions

Similar to a view with parameters

Returns a table as the result of single SELECTstatement

8/14/2019 SQL - 2071B 09

16/19

8/14/2019 SQL - 2071B 09

17/19

Verify Object Definition Text with EXEC sp_helptext

Use Views to Capture and Reuse Queries

Use Stored Procedures to Encapsulate Complex Proced

Use User-defined Functions to Encapsulate Expressio

Recommended Practices

8/14/2019 SQL - 2071B 09

18/19

Lab A: Working with Views

8/14/2019 SQL - 2071B 09

19/19

Review

Displaying the Text of a ProgrammingObject

Introduction to Views

Advantages of Views

Creating Views

Introduction to Stored Procedures

Introduction to Triggers

Introduction to User-defined Functions