displaying data from multiple tables (join ) sub queries creating sequences creating views

Displaying Data from Multiple Tables (Join))

Sub queries Creating Sequences Creating Views Dynamic SQL Queries Controlling User Access

Displaying Data from Multiple Tables (Join))

Sub queries Creating Sequences Creating Views Dynamic SQL Queries Controlling User Access

CH3 Part2CH3 Part2CH3 Part2CH3 Part2

Displaying Data from Multiple Tables

(Join)

Displaying Data from Multiple Tables

(Join)

ObjectivesObjectivesObjectivesObjectives

After completing this lesson, you After completing this lesson, you should be able to do the should be able to do the following:following: Write SELECT statements to Write SELECT statements to

access data from more than one access data from more than one table using equality and table using equality and nonequality joinsnonequality joins

View data that generally does not View data that generally does not meet a join condition by using meet a join condition by using outer joinsouter joins

Join a table to itselfJoin a table to itself

After completing this lesson, you After completing this lesson, you should be able to do the should be able to do the following:following: Write SELECT statements to Write SELECT statements to

access data from more than one access data from more than one table using equality and table using equality and nonequality joinsnonequality joins

View data that generally does not View data that generally does not meet a join condition by using meet a join condition by using outer joinsouter joins

Join a table to itselfJoin a table to itself

EMPNO DEPTNO LOC----- ------- -------- 7839 10 NEW YORK 7698 30 CHICAGO 7782 10 NEW YORK 7566 20 DALLAS 7654 30 CHICAGO 7499 30 CHICAGO...14 rows selected.

EMPNO DEPTNO LOC----- ------- -------- 7839 10 NEW YORK 7698 30 CHICAGO 7782 10 NEW YORK 7566 20 DALLAS 7654 30 CHICAGO 7499 30 CHICAGO...14 rows selected.

Obtaining Data from Obtaining Data from Multiple TablesMultiple Tables

Obtaining Data from Obtaining Data from Multiple TablesMultiple Tables

EMP EMP DEPT DEPT EMPNO ENAME ... DEPTNO------ ----- ... ------ 7839 KING ... 10 7698 BLAKE ... 30 ... 7934 MILLER ... 10

DEPTNO DNAME LOC ------ ---------- -------- 10 ACCOUNTING NEW YORK 20 RESEARCH DALLAS 30 SALES CHICAGO 40 OPERATIONS BOSTON

What Is a Join?What Is a Join?What Is a Join?What Is a Join?

Use a join to query data from Use a join to query data from more than one table.more than one table.

Write the join condition in the Write the join condition in the WHERE clause.WHERE clause.

Prefix the column name with the Prefix the column name with the table name when the same column table name when the same column name appears in more than one name appears in more than one table.table.

Use a join to query data from Use a join to query data from more than one table.more than one table.

Write the join condition in the Write the join condition in the WHERE clause.WHERE clause.

Prefix the column name with the Prefix the column name with the table name when the same column table name when the same column name appears in more than one name appears in more than one table.table.

SELECT table1.column, table2.columnFROM table1, table2WHERE table1.column1 = table2.column2;


Cartesian ProductCartesian ProductCartesian ProductCartesian Product

A Cartesian product is formed A Cartesian product is formed when:when: A join condition is omittedA join condition is omitted A join condition is invalidA join condition is invalid All rows in the first table are joined to All rows in the first table are joined to

all rows in the second tableall rows in the second table To avoid a Cartesian product, To avoid a Cartesian product,

always include a valid join always include a valid join condition in a WHERE clause.condition in a WHERE clause.

A Cartesian product is formed A Cartesian product is formed when:when: A join condition is omittedA join condition is omitted A join condition is invalidA join condition is invalid All rows in the first table are joined to All rows in the first table are joined to

all rows in the second tableall rows in the second table To avoid a Cartesian product, To avoid a Cartesian product,

always include a valid join always include a valid join condition in a WHERE clause.condition in a WHERE clause.

Generating a Cartesian Generating a Cartesian ProductProduct

Generating a Cartesian Generating a Cartesian ProductProduct

ENAME DNAME------ ----------KING ACCOUNTINGBLAKE ACCOUNTING ...KING RESEARCHBLAKE RESEARCH...56 rows selected.

ENAME DNAME------ ----------KING ACCOUNTINGBLAKE ACCOUNTING ...KING RESEARCHBLAKE RESEARCH...56 rows selected.

EMP (14 rows) EMP (14 rows) DEPT (4 rows) DEPT (4 rows)

EMPNO ENAME ... DEPTNO------ ----- ... ------ 7839 KING ... 10 7698 BLAKE ... 30 ... 7934 MILLER ... 10

EMPNO ENAME ... DEPTNO------ ----- ... ------ 7839 KING ... 10 7698 BLAKE ... 30 ... 7934 MILLER ... 10



““CartesianCartesianproduct: product:

14*4=56 rows”14*4=56 rows”

Types of JoinsTypes of JoinsTypes of JoinsTypes of Joins

EquijoinEquijoin Non-equijoinNon-equijoin Outer joinOuter join Self joinSelf join

What Is an Equijoin?What Is an Equijoin?What Is an Equijoin?What Is an Equijoin?EMP EMP DEPT DEPT EMPNO ENAME DEPTNO------ ------- ------- 7839 KING 10 7698 BLAKE 30 7782 CLARK 10 7566 JONES 20 7654 MARTIN 30 7499 ALLEN 30 7844 TURNER 30 7900 JAMES 30 7521 WARD 30 7902 FORD 20 7369 SMITH 20...14 rows selected.

DEPTNO DNAME LOC ------- ---------- -------- 10 ACCOUNTING NEW YORK 30 SALES CHICAGO 10 ACCOUNTING NEW YORK 20 RESEARCH DALLAS 30 SALES CHICAGO 30 SALES CHICAGO 30 SALES CHICAGO 30 SALES CHICAGO 30 SALES CHICAGO 20 RESEARCH DALLAS 20 RESEARCH DALLAS...14 rows selected.

Foreign keyForeign key Primary keyPrimary key

Retrieving Records Retrieving Records with Equijoinswith Equijoins

Retrieving Records Retrieving Records with Equijoinswith Equijoins

SQL> SELECT emp.empno, emp.ename, emp.deptno, 2 dept.deptno, dept.loc 3 FROM emp, dept 4 WHERE emp.deptno=dept.deptno;

EMPNO ENAME DEPTNO DEPTNO LOC----- ------ ------ ------ --------- 7839 KING 10 10 NEW YORK 7698 BLAKE 30 30 CHICAGO 7782 CLARK 10 10 NEW YORK 7566 JONES 20 20 DALLAS...14 rows selected.

Qualifying Ambiguous Qualifying Ambiguous Column NamesColumn Names

Qualifying Ambiguous Qualifying Ambiguous Column NamesColumn Names

Use table prefixes to qualify Use table prefixes to qualify column names that are in multiple column names that are in multiple tables.tables.

Improve performance by using Improve performance by using table prefixes.table prefixes.

Distinguish columns that have Distinguish columns that have identical names but reside in identical names but reside in different tables by using column different tables by using column aliases.aliases.

Use table prefixes to qualify Use table prefixes to qualify column names that are in multiple column names that are in multiple tables.tables.

Improve performance by using Improve performance by using table prefixes.table prefixes.

Distinguish columns that have Distinguish columns that have identical names but reside in identical names but reside in different tables by using column different tables by using column aliases.aliases.

Additional Search Additional Search ConditionsConditions

Using the AND Operator Using the AND Operator

Additional Search Additional Search ConditionsConditions

Using the AND Operator Using the AND Operator EMP EMP DEPT DEPT EMPNO ENAME DEPTNO------ ------- ------- 7839 KING 10 7698 BLAKE 30 7782 CLARK 10 7566 JONES 20 7654 MARTIN 30 7499 ALLEN 30 7844 TURNER 30 7900 JAMES 30 7521 WARD 30 7902 FORD 20 7369 SMITH 20...14 rows selected.

DEPTNO DNAME LOC ------ --------- -------- 10 ACCOUNTING NEW YORK 30 SALES CHICAGO 10 ACCOUNTING NEW YORK 20 RESEARCH DALLAS 30 SALES CHICAGO 30 SALES CHICAGO 30 SALES CHICAGO 30 SALES CHICAGO 30 SALES CHICAGO 20 RESEARCH DALLAS 20 RESEARCH DALLAS...14 rows selected.

Using Table AliasesUsing Table AliasesUsing Table AliasesUsing Table Aliases Simplify queries by using table Simplify queries by using table

aliases.aliases.

Simplify queries by using table Simplify queries by using table aliases.aliases.SQL> SELECT emp.empno, emp.ename, emp.deptno,

2 dept.deptno, dept.loc

3 FROM emp, dept

4 WHERE emp.deptno=dept.deptno;

SQL> SELECT e.empno, e.ename, e.deptno,

2 d.deptno, d.loc

3 FROM emp e, dept d

4 WHERE e.deptno= d.deptno;

Joining More Than Two Joining More Than Two TablesTables

Joining More Than Two Joining More Than Two TablesTables

NAME CUSTID----------- ------JOCKSPORTS 100TKB SPORT SHOP 101VOLLYRITE 102JUST TENNIS 103K+T SPORTS 105SHAPE UP 106WOMENS SPORTS 107... ...9 rows selected.

NAME CUSTID----------- ------JOCKSPORTS 100TKB SPORT SHOP 101VOLLYRITE 102JUST TENNIS 103K+T SPORTS 105SHAPE UP 106WOMENS SPORTS 107... ...9 rows selected.

CUSTOMER CUSTOMER

CUSTID ORDID------- ------- 101 610 102 611 104 612 106 601 102 602 106 604 106 605... 21 rows selected.

CUSTID ORDID------- ------- 101 610 102 611 104 612 106 601 102 602 106 604 106 605... 21 rows selected.

ORD ORD

ORDID ITEMID------ ------- 610 3 611 1 612 1 601 1 602 1...64 rows selected.

ORDID ITEMID------ ------- 610 3 611 1 612 1 601 1 602 1...64 rows selected.

ITEM ITEM

Non-EquijoinsNon-EquijoinsNon-EquijoinsNon-EquijoinsEMPEMP SALGRADESALGRADE

““salary in the EMP salary in the EMP table is between table is between low salary and high low salary and high salary in the SALGRADEsalary in the SALGRADEtable”table”

EMPNO ENAME SAL------ ------- ------ 7839 KING 5000 7698 BLAKE 2850 7782 CLARK 2450 7566 JONES 2975 7654 MARTIN 1250 7499 ALLEN 1600 7844 TURNER 1500 7900 JAMES 950...14 rows selected.

GRADE LOSAL HISAL----- ----- ------1 700 12002 1201 14003 1401 20004 2001 30005 3001 9999

Retrieving Records Retrieving Records with Non-Equijoinswith Non-EquijoinsRetrieving Records Retrieving Records with Non-Equijoinswith Non-Equijoins

ENAME SAL GRADE---------- --------- ---------JAMES 950 1SMITH 800 1ADAMS 1100 1...14 rows selected.

SQL> SELECT e.ename, e.sal, s.grade

2 FROM emp e, salgrade s

3 WHERE e.sal

4 BETWEEN s.losal AND s.hisal;

Outer JoinsOuter JoinsOuter JoinsOuter JoinsEMP EMP DEPT DEPT

No employee in theNo employee in theOPERATIONS departmentOPERATIONS department

ENAME DEPTNO----- ------KING 10BLAKE 30CLARK 10JONES 20...

DEPTNO DNAME------ ----------10 ACCOUNTING30 SALES10 ACCOUNTING20 RESEARCH...40 OPERATIONS

Outer JoinsOuter JoinsOuter JoinsOuter Joins You use an outer join to also see You use an outer join to also see

rows that do not usually meet the rows that do not usually meet the join condition.join condition.

Outer join operator is the plus sign Outer join operator is the plus sign (+)(+)..

You use an outer join to also see You use an outer join to also see rows that do not usually meet the rows that do not usually meet the join condition.join condition.

Outer join operator is the plus sign Outer join operator is the plus sign (+)(+)..SELECT table1.column, table2.column

FROM table1, table2

WHERE table1.column(+) = table2.column;

SELECT table1.column, table2.column

FROM table1, table2

WHERE table1.column(+) = table2.column;


FROM table1, table2

WHERE table1.column = table2.column(+);


FROM table1, table2

WHERE table1.column = table2.column(+);

Using Outer JoinsUsing Outer JoinsUsing Outer JoinsUsing Outer Joins

SQL> SELECT e.ename, d.deptno, d.dname

2 FROM emp e, dept d

3 WHERE e.deptno(+) = d.deptno

4 ORDER BY e.deptno;

ENAME DEPTNO DNAME---------- --------- -------------KING 10 ACCOUNTINGCLARK 10 ACCOUNTING... 40 OPERATIONS15 rows selected.

Self JoinsSelf JoinsSelf JoinsSelf Joins

EMP (WORKER)EMP (WORKER) EMP (MANAGER)EMP (MANAGER)

““MGR in the WORKER table is equal to EMPNO in the MGR in the WORKER table is equal to EMPNO in the MANAGER table”MANAGER table”

EMPNO ENAME MGR----- ------ ---- 7839 KING 7698 BLAKE 7839 7782 CLARK 7839 7566 JONES 7839 7654 MARTIN 7698 7499 ALLEN 7698

EMPNO ENAME----- --------

7839 KING 7839 KING 7839 KING 7698 BLAKE 7698 BLAKE

Joining a Table to ItselfJoining a Table to ItselfJoining a Table to ItselfJoining a Table to Itself

WORKER.ENAME||'WORKSFOR'||MANAG-------------------------------BLAKE works for KINGCLARK works for KINGJONES works for KINGMARTIN works for BLAKE...13 rows selected.

WORKER.ENAME||'WORKSFOR'||MANAG-------------------------------BLAKE works for KINGCLARK works for KINGJONES works for KINGMARTIN works for BLAKE...13 rows selected.

SQL> SELECT worker.ename||' works for '||manager.ename

2 FROM emp worker, emp manager

3 WHERE worker.mgr = manager.empno;

SummarySummarySummarySummary

EquijoinEquijoin Non-equijoinNon-equijoin Outer joinOuter join Self joinSelf join



Sub queriesSub queries


After completing this lesson, you After completing this lesson, you should be able to do the should be able to do the following:following: Describe the types of problems Describe the types of problems

that subqueries can solvethat subqueries can solve Define subqueriesDefine subqueries List the types of subqueriesList the types of subqueries Write single-row and multiple-row Write single-row and multiple-row

subqueriessubqueries

After completing this lesson, you After completing this lesson, you should be able to do the should be able to do the following:following: Describe the types of problems Describe the types of problems

that subqueries can solvethat subqueries can solve Define subqueriesDefine subqueries List the types of subqueriesList the types of subqueries Write single-row and multiple-row Write single-row and multiple-row

subqueriessubqueries

Using a Subquery Using a Subquery to Solve a Problemto Solve a ProblemUsing a Subquery Using a Subquery to Solve a Problemto Solve a Problem ““Who has a salary greater than Who has a salary greater than

Jones’?”Jones’?”

““Who has a salary greater than Who has a salary greater than Jones’?”Jones’?”

“Which employees have a salary greater than Jones’ salary?”

Main Query

??

“What is Jones’ salary?”??

Subquery

SubqueriesSubqueriesSubqueriesSubqueries

The subquery (inner query) executes once before the main query.The subquery (inner query) executes once before the main query. The result of the subquery is used by the main query (outer The result of the subquery is used by the main query (outer

query).query).

The subquery (inner query) executes once before the main query.The subquery (inner query) executes once before the main query. The result of the subquery is used by the main query (outer The result of the subquery is used by the main query (outer

query).query).

SELECT select_listFROM tableWHERE expr operator

(SELECT select_list FROM table);

2975

SQL> SELECT ename 2 FROM emp 3 WHERE sal > 4 (SELECT sal 5 FROM emp 6 WHERE empno=7566);

Using a SubqueryUsing a SubqueryUsing a SubqueryUsing a Subquery

ENAME----------KINGFORDSCOTT

ENAME----------KINGFORDSCOTT

Guidelines for Using Guidelines for Using SubqueriesSubqueries

Guidelines for Using Guidelines for Using SubqueriesSubqueries

Enclose subqueries in parentheses. Enclose subqueries in parentheses. Place subqueries on the right side Place subqueries on the right side

of the comparison operator.of the comparison operator. Do not add an ORDER BY clause to Do not add an ORDER BY clause to

a subquery.a subquery. Use single-row operators with Use single-row operators with

single-row subqueries.single-row subqueries. Use multiple-row operators with Use multiple-row operators with

multiple-row subqueries.multiple-row subqueries.

Enclose subqueries in parentheses. Enclose subqueries in parentheses. Place subqueries on the right side Place subqueries on the right side

of the comparison operator.of the comparison operator. Do not add an ORDER BY clause to Do not add an ORDER BY clause to

a subquery.a subquery. Use single-row operators with Use single-row operators with

single-row subqueries.single-row subqueries. Use multiple-row operators with Use multiple-row operators with

multiple-row subqueries.multiple-row subqueries.

Types of SubqueriesTypes of SubqueriesTypes of SubqueriesTypes of Subqueries Single-row subquerySingle-row subquery Single-row subquerySingle-row subquery

Main query

Subquery returnsreturns

CLERKCLERK

• Multiple-row subquery• Multiple-row subquery

CLERKCLERKMANAGERMANAGER

Main query


• Multiple-column subquery• Multiple-column subquery

CLERK 7900CLERK 7900MANAGER 7698MANAGER 7698

Main query


Single-Row SubqueriesSingle-Row SubqueriesSingle-Row SubqueriesSingle-Row Subqueries Return only one rowReturn only one row Use single-row comparison Use single-row comparison

operatorsoperators

Return only one rowReturn only one row Use single-row comparison Use single-row comparison

operatorsoperatorsOperator

=

>

>=

<

<=

<>

Meaning

Equal to

Greater than

Greater than or equal to

Less than

Less than or equal to

Not equal to

Executing Single-Row Executing Single-Row SubqueriesSubqueries

Executing Single-Row Executing Single-Row SubqueriesSubqueries

CLERK

1100

ENAME JOB---------- ---------MILLER CLERK

ENAME JOB---------- ---------MILLER CLERK

SQL> SELECT ename, job 2 FROM emp 3 WHERE job = 4 (SELECT job 5 FROM emp 6 WHERE empno = 7369) 7 AND sal > 8 (SELECT sal 9 FROM emp 10 WHERE empno = 7876);

Using Group Functions Using Group Functions in a Subqueryin a Subquery

Using Group Functions Using Group Functions in a Subqueryin a Subquery

800

ENAME JOB SAL---------- --------- ---------SMITH CLERK 800

ENAME JOB SAL---------- --------- ---------SMITH CLERK 800

SQL> SELECT ename, job, sal 2 FROM emp 3 WHERE sal = 4 (SELECT MIN(sal) 5 FROM emp);

HAVING Clause with HAVING Clause with SubqueriesSubqueries

HAVING Clause with HAVING Clause with SubqueriesSubqueries

The Oracle Server executes The Oracle Server executes subqueries first.subqueries first.

The Oracle Server returns results The Oracle Server returns results into the HAVING clause of the into the HAVING clause of the main query.main query.

The Oracle Server executes The Oracle Server executes subqueries first.subqueries first.

The Oracle Server returns results The Oracle Server returns results into the HAVING clause of the into the HAVING clause of the main query.main query.

800

SQL> SELECT deptno, MIN(sal) 2 FROM emp 3 GROUP BY deptno 4 HAVING MIN(sal) > 5 (SELECT MIN(sal) 6 FROM emp 7 WHERE deptno = 20);

What Is Wrong What Is Wrong with This Statement?with This Statement?

What Is Wrong What Is Wrong with This Statement?with This Statement?

ERROR:ORA-01427: single-row subquery returns more thanone row

no rows selected

ERROR:ORA-01427: single-row subquery returns more thanone row

no rows selected

SQL> SELECT empno, ename 2 FROM emp 3 WHERE sal = 4 (SELECT MIN(sal) 5 FROM emp 6 GROUP BY deptno);

Single-row operator with

Single-row operator with

multiple-row subquery

multiple-row subquery

Will This Statement Will This Statement Work?Work?

Will This Statement Will This Statement Work?Work?

no rows selectedno rows selected

Subquery returns no values

Subquery returns no values

SQL> SELECT ename, job 2 FROM emp 3 WHERE job = 4 (SELECT job 5 FROM emp 6 WHERE ename='SMYTHE');

Multiple-Row SubqueriesMultiple-Row SubqueriesMultiple-Row SubqueriesMultiple-Row Subqueries Return more than one rowReturn more than one row Use multiple-row comparison Use multiple-row comparison

operatorsoperators

Return more than one rowReturn more than one row Use multiple-row comparison Use multiple-row comparison

operatorsoperatorsOperator

IN

ANY

ALL

Meaning

Equal to any member in the list

Compare value to each value returned by

the subquery

Compare value to every value returned by

the subquery

Using ANY Operator Using ANY Operator in Multiple-Row in Multiple-Row

SubqueriesSubqueries

Using ANY Operator Using ANY Operator in Multiple-Row in Multiple-Row

SubqueriesSubqueries9508001100

1300

EMPNO ENAME JOB--------- ---------- --------- 7654 MARTIN SALESMAN 7521 WARD SALESMAN

EMPNO ENAME JOB--------- ---------- --------- 7654 MARTIN SALESMAN 7521 WARD SALESMAN

SQL> SELECT empno, ename, job 2 FROM emp 3 WHERE sal < ANY 4 (SELECT sal 5 FROM emp 6 WHERE job = 'CLERK') 7 AND job <> 'CLERK';

Using ALL Operator Using ALL Operator in Multiple-Row in Multiple-Row

SubqueriesSubqueries

Using ALL Operator Using ALL Operator in Multiple-Row in Multiple-Row

SubqueriesSubqueries2916.6667

2175

1566.6667

EMPNO ENAME JOB--------- ---------- --------- 7839 KING PRESIDENT 7566 JONES MANAGER 7902 FORD ANALYST 7788 SCOTT ANALYST

EMPNO ENAME JOB--------- ---------- --------- 7839 KING PRESIDENT 7566 JONES MANAGER 7902 FORD ANALYST 7788 SCOTT ANALYST

SQL> SELECT empno, ename, job 2 FROM emp 3 WHERE sal > ALL 4 (SELECT avg(sal) 5 FROM emp 6 GROUP BY deptno);

SummarySummarySummarySummary

Subqueries are useful when a Subqueries are useful when a query is based on unknown query is based on unknown values.values.

Subqueries are useful when a Subqueries are useful when a query is based on unknown query is based on unknown values.values.SELECT select_list

FROM tableWHERE expr operator

(SELECT select_list FROM table);

Creating SequencesCreating Sequences

What Is a Sequence?What Is a Sequence?What Is a Sequence?What Is a Sequence?

Automatically generates unique Automatically generates unique numbersnumbers

Is a sharable objectIs a sharable object Is typically used to create a primary Is typically used to create a primary

key valuekey value Replaces application codeReplaces application code Speeds up the efficiency of accessing Speeds up the efficiency of accessing

sequence values when cached in sequence values when cached in memorymemory

Automatically generates unique Automatically generates unique numbersnumbers

Is a sharable objectIs a sharable object Is typically used to create a primary Is typically used to create a primary

key valuekey value Replaces application codeReplaces application code Speeds up the efficiency of accessing Speeds up the efficiency of accessing

sequence values when cached in sequence values when cached in memorymemory

The CREATE SEQUENCE The CREATE SEQUENCE StatementStatement

The CREATE SEQUENCE The CREATE SEQUENCE StatementStatement

Define a sequence to generate Define a sequence to generate sequential numbers automatically.sequential numbers automatically.

Define a sequence to generate Define a sequence to generate sequential numbers automatically.sequential numbers automatically.

CREATE SEQUENCE sequence[INCREMENT BY n][START WITH n][{MAXVALUE n | NOMAXVALUE}][{MINVALUE n | NOMINVALUE}][{CYCLE | NOCYCLE}][{CACHE n | NOCACHE}];

CREATE SEQUENCE sequence[INCREMENT BY n][START WITH n][{MAXVALUE n | NOMAXVALUE}][{MINVALUE n | NOMINVALUE}][{CYCLE | NOCYCLE}][{CACHE n | NOCACHE}];

Creating a SequenceCreating a SequenceCreating a SequenceCreating a Sequence Create a sequence named DEPT_DEPTNO to be used for the primary Create a sequence named DEPT_DEPTNO to be used for the primary

key of thekey of theDEPT table.DEPT table.

Do not use the CYCLE option.Do not use the CYCLE option.

Create a sequence named DEPT_DEPTNO to be used for the primary Create a sequence named DEPT_DEPTNO to be used for the primary key of thekey of theDEPT table.DEPT table.

Do not use the CYCLE option.Do not use the CYCLE option.

SQL> CREATE SEQUENCE dept_deptno 2 INCREMENT BY 1 3 START WITH 91 4 MAXVALUE 100 5 NOCACHE 6 NOCYCLE;Sequence created.Sequence created.

SQL> CREATE SEQUENCE dept_deptno 2 INCREMENT BY 1 3 START WITH 91 4 MAXVALUE 100 5 NOCACHE 6 NOCYCLE;Sequence created.Sequence created.

Confirming SequencesConfirming SequencesConfirming SequencesConfirming Sequences

Verify your sequence values in the Verify your sequence values in the USER_SEQUENCES data USER_SEQUENCES data dictionary table.dictionary table.

The LAST_NUMBER column The LAST_NUMBER column displays the next available displays the next available sequence number.sequence number.

Verify your sequence values in the Verify your sequence values in the USER_SEQUENCES data USER_SEQUENCES data dictionary table.dictionary table.

The LAST_NUMBER column The LAST_NUMBER column displays the next available displays the next available sequence number.sequence number.

SQL> SELECT sequence_name, min_value, max_value, 2 increment_by, last_number 3 FROM user_sequences;

SQL> SELECT sequence_name, min_value, max_value, 2 increment_by, last_number 3 FROM user_sequences;

NEXTVAL and CURRVAL NEXTVAL and CURRVAL PseudocolumnsPseudocolumns

NEXTVAL and CURRVAL NEXTVAL and CURRVAL PseudocolumnsPseudocolumns

NEXTVAL returns the next NEXTVAL returns the next available sequence value.available sequence value.

It returns a unique value every It returns a unique value every time it is referenced, even for time it is referenced, even for different users.different users.

CURRVAL obtains the current CURRVAL obtains the current sequence value.sequence value.

NEXTVAL must be issued for that NEXTVAL must be issued for that sequence before CURRVAL sequence before CURRVAL contains a value.contains a value.

NEXTVAL returns the next NEXTVAL returns the next available sequence value.available sequence value.

It returns a unique value every It returns a unique value every time it is referenced, even for time it is referenced, even for different users.different users.

CURRVAL obtains the current CURRVAL obtains the current sequence value.sequence value.

NEXTVAL must be issued for that NEXTVAL must be issued for that sequence before CURRVAL sequence before CURRVAL contains a value.contains a value.

Using a SequenceUsing a SequenceUsing a SequenceUsing a Sequence Insert a new department named Insert a new department named

“MARKETING” in San Diego.“MARKETING” in San Diego.

View the current value for the View the current value for the DEPT_DEPTNO sequence.DEPT_DEPTNO sequence.

Insert a new department named Insert a new department named “MARKETING” in San Diego.“MARKETING” in San Diego.

View the current value for the View the current value for the DEPT_DEPTNO sequence.DEPT_DEPTNO sequence.

SQL> INSERT INTO dept(deptno, dname, loc) 2 VALUES (dept_deptno.NEXTVAL, 3 'MARKETING', 'SAN DIEGO');1 row created.1 row created.

SQL> INSERT INTO dept(deptno, dname, loc) 2 VALUES (dept_deptno.NEXTVAL, 3 'MARKETING', 'SAN DIEGO');1 row created.1 row created.

SQL> SELECT dept_deptno.CURRVAL 2 FROM dual;

SQL> SELECT dept_deptno.CURRVAL 2 FROM dual;

Using a SequenceUsing a SequenceUsing a SequenceUsing a Sequence

Caching sequence values in memory Caching sequence values in memory allows faster access to those values.allows faster access to those values.

Gaps in sequence values can occur Gaps in sequence values can occur when:when: A rollback occursA rollback occurs The system crashesThe system crashes A sequence is used in another tableA sequence is used in another table

View the next available sequence, if it View the next available sequence, if it was created with NOCACHE, by was created with NOCACHE, by querying the USER_SEQUENCES querying the USER_SEQUENCES table.table.

Caching sequence values in memory Caching sequence values in memory allows faster access to those values.allows faster access to those values.

Gaps in sequence values can occur Gaps in sequence values can occur when:when: A rollback occursA rollback occurs The system crashesThe system crashes A sequence is used in another tableA sequence is used in another table

View the next available sequence, if it View the next available sequence, if it was created with NOCACHE, by was created with NOCACHE, by querying the USER_SEQUENCES querying the USER_SEQUENCES table.table.

Modifying a SequenceModifying a SequenceModifying a SequenceModifying a Sequence

Change the increment value, Change the increment value, maximum value, minimum value, maximum value, minimum value, cycle option, or cache option.cycle option, or cache option.

Change the increment value, Change the increment value, maximum value, minimum value, maximum value, minimum value, cycle option, or cache option.cycle option, or cache option.

SQL> ALTER SEQUENCE dept_deptno 2 INCREMENT BY 1 3 MAXVALUE 999999 4 NOCACHE 5 NOCYCLE;Sequence altered.Sequence altered.

SQL> ALTER SEQUENCE dept_deptno 2 INCREMENT BY 1 3 MAXVALUE 999999 4 NOCACHE 5 NOCYCLE;Sequence altered.Sequence altered.

Guidelines for Modifying Guidelines for Modifying a Sequencea Sequence

Guidelines for Modifying Guidelines for Modifying a Sequencea Sequence

You must be the owner or have the You must be the owner or have the ALTER privilege for the sequence.ALTER privilege for the sequence.

Only future sequence numbers are Only future sequence numbers are affected.affected.

The sequence must be dropped and The sequence must be dropped and

re-created to restart the sequence re-created to restart the sequence at a different number.at a different number.

You must be the owner or have the You must be the owner or have the ALTER privilege for the sequence.ALTER privilege for the sequence.

Only future sequence numbers are Only future sequence numbers are affected.affected.

The sequence must be dropped and The sequence must be dropped and

re-created to restart the sequence re-created to restart the sequence at a different number.at a different number.

Removing a SequenceRemoving a SequenceRemoving a SequenceRemoving a Sequence

Remove a sequence from the data Remove a sequence from the data dictionary by using the DROP dictionary by using the DROP SEQUENCE statement.SEQUENCE statement.

Once removed, the sequence can Once removed, the sequence can no longer be referenced.no longer be referenced.

Remove a sequence from the data Remove a sequence from the data dictionary by using the DROP dictionary by using the DROP SEQUENCE statement.SEQUENCE statement.

Once removed, the sequence can Once removed, the sequence can no longer be referenced.no longer be referenced.

SQL> DROP SEQUENCE dept_deptno;Sequence dropped.Sequence dropped.

SQL> DROP SEQUENCE dept_deptno;Sequence dropped.Sequence dropped.

Creating ViewsCreating Views

What Is a View?What Is a View?What Is a View?What Is a View?

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

----- ------- --------- ----- --------- ----- ----- -------

7839 KING PRESIDENT 17-NOV-81 5000 10

7698 BLAKE MANAGER 7839 01-MAY-81 2850 30

7782 CLARK MANAGER 7839 09-JUN-81 2450 10

7566 JONES MANAGER 7839 02-APR-81 2975 20

7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30

7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30

7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30

7900 JAMES CLERK 7698 03-DEC-81 950 30

7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30

7902 FORD ANALYST 7566 03-DEC-81 3000 20

7369 SMITH CLERK 7902 17-DEC-80 800 20

7788 SCOTT ANALYST 7566 09-DEC-82 3000 20

7876 ADAMS CLERK 7788 12-JAN-83 1100 20

7934 MILLER CLERK 7782 23-JAN-82 1300 10


----- ------- --------- ----- --------- ----- ----- -------



7782 CLARK MANAGER 7839 09-JUN-81 2450 10





7900 JAMES CLERK 7698 03-DEC-81 950 30


7902 FORD ANALYST 7566 03-DEC-81 3000 20

7369 SMITH CLERK 7902 17-DEC-80 800 20


7876 ADAMS CLERK 7788 12-JAN-83 1100 20

7934 MILLER CLERK 7782 23-JAN-82 1300 10

EMP TableEMP TableEMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

----- -------- --------- ---- --------- ------ ----- -------


7782 CLARK MANAGER 7839 09-JUN-81 1500 300 10

7934 MILLER CLERK 7782 23-JAN-82 1300 10



7876 ADAMS CLERK 7788 12-JAN-83 1100 20

7369 SMITH CLERK 7902 17-DEC-80 800 20

7902 FORD ANALYST 7566 03-DEC-81 3000 20





7900 JAMES CLERK 7698 03-DEC-81 950 30



----- -------- --------- ---- --------- ------ ----- -------


7782 CLARK MANAGER 7839 09-JUN-81 1500 300 10

7934 MILLER CLERK 7782 23-JAN-82 1300 10



7876 ADAMS CLERK 7788 12-JAN-83 1100 20

7369 SMITH CLERK 7902 17-DEC-80 800 20

7902 FORD ANALYST 7566 03-DEC-81 3000 20





7900 JAMES CLERK 7698 03-DEC-81 950 30


EMPNO ENAME JOB ------ -------- ----------- 7839 KING PRESIDENT 7782 CLARK MANAGER 7934 MILLER CLERK

EMPVU10 ViewEMPVU10 View

Why Use Views?Why Use Views?Why Use Views?Why Use Views?

To restrict data accessTo restrict data access To make complex queries easyTo make complex queries easy To allow data independenceTo allow data independence To present different views of the To present different views of the

same datasame data

To restrict data accessTo restrict data access To make complex queries easyTo make complex queries easy To allow data independenceTo allow data independence To present different views of the To present different views of the

same datasame data

Simple Views Simple Views and Complex Viewsand Complex Views

Simple Views Simple Views and Complex Viewsand Complex Views

Feature Simple ViewsComplex Views

Number of tables One One or more

Contain functions No Yes

Contain groups of data No Yes

DML through view Yes Not always

Creating a ViewCreating a ViewCreating a ViewCreating a View You embed a subquery within the CREATE VIEW statement.You embed a subquery within the CREATE VIEW statement.

The subquery can contain complex SELECT syntax.The subquery can contain complex SELECT syntax. The subquery cannot contain an ORDER BY clause.The subquery cannot contain an ORDER BY clause.

You embed a subquery within the CREATE VIEW statement.You embed a subquery within the CREATE VIEW statement.

The subquery can contain complex SELECT syntax.The subquery can contain complex SELECT syntax. The subquery cannot contain an ORDER BY clause.The subquery cannot contain an ORDER BY clause.

CREATE [OR REPLACE] VIEW view_nameAS subquery;

CREATE [OR REPLACE] VIEW view_nameAS subquery;

Creating a ViewCreating a ViewCreating a ViewCreating a View Create a view, EMPVU10, that contains Create a view, EMPVU10, that contains

details of employees in department 10.details of employees in department 10.

Create a view, EMPVU10, that contains Create a view, EMPVU10, that contains details of employees in department 10.details of employees in department 10.

• Describe the structure of the view by using the SQL*Plus DESCRIBE command.

• Describe the structure of the view by using the SQL*Plus DESCRIBE command.

SQL> DESCRIBE empvu10SQL> DESCRIBE empvu10

SQL> CREATE VIEW empvu10 2 AS SELECT empno, ename, job 3 FROM emp 4 WHERE deptno = 10;View created.View created.

Creating a ViewCreating a ViewCreating a ViewCreating a View Create a view by using column Create a view by using column

aliases in the subquery.aliases in the subquery.

Select the columns from this view Select the columns from this view by the given alias names.by the given alias names.

Create a view by using column Create a view by using column aliases in the subquery.aliases in the subquery.

Select the columns from this view Select the columns from this view by the given alias names.by the given alias names.

SQL> CREATE VIEW salvu30 2 AS SELECT empno EMPLOYEE_NUMBER, ename NAME, 3 sal SALARY 4 FROM emp 5 WHERE deptno = 30;View created.View created.

Retrieving Data from a Retrieving Data from a ViewView

Retrieving Data from a Retrieving Data from a ViewView

EMPLOYEE_NUMBER NAME SALARY--------------- ---------- --------- 7698 BLAKE 2850 7654 MARTIN 1250 7499 ALLEN 1600 7844 TURNER 1500 7900 JAMES 950 7521 WARD 1250

6 rows selected.

EMPLOYEE_NUMBER NAME SALARY--------------- ---------- --------- 7698 BLAKE 2850 7654 MARTIN 1250 7499 ALLEN 1600 7844 TURNER 1500 7900 JAMES 950 7521 WARD 1250

6 rows selected.

SQL> SELECT * 2 FROM salvu30;

Querying a ViewQuerying a ViewQuerying a ViewQuerying a View

USER_VIEWSUSER_VIEWS EMPVU10EMPVU10SELECT empno, ename, jobFROM empWHERE deptno = 10;

USER_VIEWSUSER_VIEWS EMPVU10EMPVU10SELECT empno, ename, jobFROM empWHERE deptno = 10;

SQL*PlusSQL*Plus

SELECT *FROM empvu10;

EMP

7839 KING PRESIDENT7782 CLARK MANAGER7934 MILLER CLERK

Modifying a ViewModifying a ViewModifying a ViewModifying a View Modify the EMPVU10 view by using Modify the EMPVU10 view by using

CREATE OR REPLACE VIEW CREATE OR REPLACE VIEW clause. Add an alias for each column clause. Add an alias for each column name.name.

Column aliases in the CREATE Column aliases in the CREATE VIEW clause are listed in the same VIEW clause are listed in the same order as the columns in the order as the columns in the subquery.subquery.

Modify the EMPVU10 view by using Modify the EMPVU10 view by using CREATE OR REPLACE VIEW CREATE OR REPLACE VIEW clause. Add an alias for each column clause. Add an alias for each column name.name.

Column aliases in the CREATE Column aliases in the CREATE VIEW clause are listed in the same VIEW clause are listed in the same order as the columns in the order as the columns in the subquery.subquery.

SQL> CREATE OR REPLACE VIEW empvu10 2 (employee_number, employee_name, job_title) 3 AS SELECT empno, ename, job 4 FROM emp 5 WHERE deptno = 10;View created.View created.

Removing a ViewRemoving a ViewRemoving a ViewRemoving a View

Remove a view without losing data Remove a view without losing data because a view is based on because a view is based on underlying tables in the database.underlying tables in the database.

Remove a view without losing data Remove a view without losing data because a view is based on because a view is based on underlying tables in the database.underlying tables in the database.

SQL> DROP VIEW empvu10; View dropped.View dropped.

DROP VIEW view; DROP VIEW view;

Dynamic SQL QueriesDynamic SQL Queries


After completing this lesson, you After completing this lesson, you should be able to do the should be able to do the following:following: Produce queries that require an Produce queries that require an

input variableinput variable Produce more readable outputProduce more readable output

After completing this lesson, you After completing this lesson, you should be able to do the should be able to do the following:following: Produce queries that require an Produce queries that require an

input variableinput variable Produce more readable outputProduce more readable output

Interactive ReportsInteractive ReportsInteractive ReportsInteractive Reports

I want to input query values at runtime....sal = ? …

… deptno = ? … .. ename = ? ...

UserUser

Substitution VariablesSubstitution VariablesSubstitution VariablesSubstitution Variables

Use SQL*Plus substitution Use SQL*Plus substitution variables to temporarily store variables to temporarily store values.values. Single ampersand (&)Single ampersand (&) Double ampersand (&&)Double ampersand (&&) DEFINE and ACCEPT commandsDEFINE and ACCEPT commands

Pass variable values between SQL Pass variable values between SQL statements.statements.

Use SQL*Plus substitution Use SQL*Plus substitution variables to temporarily store variables to temporarily store values.values. Single ampersand (&)Single ampersand (&) Double ampersand (&&)Double ampersand (&&) DEFINE and ACCEPT commandsDEFINE and ACCEPT commands

Pass variable values between SQL Pass variable values between SQL statements.statements.

Using the & Substitution Using the & Substitution VariableVariable

Using the & Substitution Using the & Substitution VariableVariable Use a variable prefixed with an Use a variable prefixed with an

ampersand (&) to prompt the ampersand (&) to prompt the user for a value.user for a value.

Use a variable prefixed with an Use a variable prefixed with an ampersand (&) to prompt the ampersand (&) to prompt the user for a value.user for a value.SQL> SELECT empno, ename, sal, deptno

2 FROM emp 3 WHERE empno = &employee_num;

Enter value for employee_num: 73697369

EMPNO ENAME SAL DEPTNO--------- ---------- --------- --------- 7369 SMITH 800 20

Using the SET VERIFY Using the SET VERIFY CommandCommand

Using the SET VERIFY Using the SET VERIFY CommandCommand Toggling the display of the text of Toggling the display of the text of

a command before and after a command before and after SQL*Plus replaces substitution SQL*Plus replaces substitution variables with values.variables with values.

Toggling the display of the text of Toggling the display of the text of a command before and after a command before and after SQL*Plus replaces substitution SQL*Plus replaces substitution variables with values.variables with values.SQL> SET VERIFY ON

SQL> SELECT empno, ename, sal, deptno 2 FROM emp 3 WHERE empno = &employee_num;

Enter value for employee_num: 7369old 3: WHERE empno = &employee_numnew 3: WHERE empno = 7369

...

Character and Date Character and Date Values Values

with Substitution with Substitution VariablesVariables

Character and Date Character and Date Values Values

with Substitution with Substitution VariablesVariables

Use single quotation marks for date Use single quotation marks for date and character values.and character values.

Use single quotation marks for date Use single quotation marks for date and character values.and character values.SQL> SELECT ename, deptno, sal*12 2 FROM emp 3 WHERE job='&job_title';

Enter value for job_title: ANALYSTANALYST

ENAME DEPTNO SAL*12---------- --------- ---------SCOTT 20 36000FORD 20 36000

Specifying Column Specifying Column Names, Expressions, and Names, Expressions, and

Text at RuntimeText at Runtime

Specifying Column Specifying Column Names, Expressions, and Names, Expressions, and

Text at RuntimeText at Runtime Use substitution variables to Use substitution variables to supplement the following:supplement the following: WHERE conditionWHERE condition ORDER BY clauseORDER BY clause Column expressionColumn expression Table nameTable name Entire SELECT statementEntire SELECT statement

Use substitution variables to Use substitution variables to supplement the following:supplement the following: WHERE conditionWHERE condition ORDER BY clauseORDER BY clause Column expressionColumn expression Table nameTable name Entire SELECT statementEntire SELECT statement

Specifying Column Specifying Column Names, Expressions, Names, Expressions, and Text at Runtimeand Text at Runtime

Specifying Column Specifying Column Names, Expressions, Names, Expressions, and Text at Runtimeand Text at RuntimeSQL> SELECT empno, ename, job, &column_name

2 FROM emp 3 WHERE &condition 4 ORDER BY &order_column;

Enter value for column_name: salsalEnter value for condition: sal>=3000sal>=3000Enter value for order_column: enameename

EMPNO ENAME JOB SAL--------- ---------- --------- --------- 7902 FORD ANALYST 3000 7839 KING PRESIDENT 5000 7788 SCOTT ANALYST 3000

Using the && Using the && Substitution VariableSubstitution Variable

Using the && Using the && Substitution VariableSubstitution Variable Use the double-ampersand (&&) Use the double-ampersand (&&) if you want to reuse the variable if you want to reuse the variable value without prompting the value without prompting the user each time.user each time.

Use the double-ampersand (&&) Use the double-ampersand (&&) if you want to reuse the variable if you want to reuse the variable value without prompting the value without prompting the user each time.user each time.SQL> SELECT empno, ename, job, &&column_name

2 FROM emp 3 ORDER BY &column_name;

Enter value for column_name: deptnodeptno EMPNO ENAME JOB DEPTNO--------- ---------- --------- --------- 7839 KING PRESIDENT 10 7782 CLARK MANAGER 10 7934 MILLER CLERK 10...14 rows selected.

Defining User VariablesDefining User VariablesDefining User VariablesDefining User Variables

You can predefine variables using You can predefine variables using one of two SQL*Plus commands:one of two SQL*Plus commands: DEFINE: Create a CHAR datatype DEFINE: Create a CHAR datatype

user variableuser variable ACCEPT: Read user input and store it ACCEPT: Read user input and store it

in a variablein a variable If you need to predefine a variable If you need to predefine a variable

that includes spaces, you must that includes spaces, you must enclose the value within single enclose the value within single quotation marks when using the quotation marks when using the DEFINE command.DEFINE command.

You can predefine variables using You can predefine variables using one of two SQL*Plus commands:one of two SQL*Plus commands: DEFINE: Create a CHAR datatype DEFINE: Create a CHAR datatype

user variableuser variable ACCEPT: Read user input and store it ACCEPT: Read user input and store it

in a variablein a variable If you need to predefine a variable If you need to predefine a variable

that includes spaces, you must that includes spaces, you must enclose the value within single enclose the value within single quotation marks when using the quotation marks when using the DEFINE command.DEFINE command.

The ACCEPT CommandThe ACCEPT CommandThe ACCEPT CommandThe ACCEPT Command

Creates a customized prompt when Creates a customized prompt when accepting user inputaccepting user input

Explicitly defines a NUMBER or Explicitly defines a NUMBER or DATE datatype variableDATE datatype variable

Hides user input for security Hides user input for security reasonsreasons

Creates a customized prompt when Creates a customized prompt when accepting user inputaccepting user input

Explicitly defines a NUMBER or Explicitly defines a NUMBER or DATE datatype variableDATE datatype variable

Hides user input for security Hides user input for security reasonsreasons

ACCEPT variable [datatype] [FORMAT format] [PROMPT text] [HIDE]

ACCEPT variable [datatype] [FORMAT format] [PROMPT text] [HIDE]

Using the ACCEPT Using the ACCEPT CommandCommand

Using the ACCEPT Using the ACCEPT CommandCommand

ACCEPT dept PROMPT 'Provide the department name: 'SELECT * FROM deptWHERE dname = UPPER('&dept')/

Provide the department name: SalesSales

DEPTNO DNAME LOC--------- -------------- ------------- 30 SALES CHICAGO

DEFINE and UNDEFINE DEFINE and UNDEFINE CommandsCommands

DEFINE and UNDEFINE DEFINE and UNDEFINE CommandsCommands A variable remains defined until you A variable remains defined until you

either:either: Use the UNDEFINE command to clear itUse the UNDEFINE command to clear it Exit SQL*PlusExit SQL*Plus

You can verify your changes with the You can verify your changes with the DEFINE command.DEFINE command.

To define variables for every session, To define variables for every session, modify your modify your login.sqllogin.sql file so that the file so that the variables are created at startup.variables are created at startup.

A variable remains defined until you A variable remains defined until you either:either: Use the UNDEFINE command to clear itUse the UNDEFINE command to clear it Exit SQL*PlusExit SQL*Plus

You can verify your changes with the You can verify your changes with the DEFINE command.DEFINE command.

To define variables for every session, To define variables for every session, modify your modify your login.sqllogin.sql file so that the file so that the variables are created at startup.variables are created at startup.

Using the DEFINE Using the DEFINE CommandCommand

Using the DEFINE Using the DEFINE CommandCommand

Create a variable to hold the Create a variable to hold the department name.department name.

Create a variable to hold the Create a variable to hold the department name.department name.

DEFINE DEPTNAME = "sales" (CHAR) DEFINE DEPTNAME = "sales" (CHAR)

• Use the variable as you would any other variable.• Use the variable as you would any other

variable.

SQL> DEFINE deptname = salesSQL> DEFINE deptname

SQL> SELECT * 2 FROM dept 3 WHERE dname = UPPER('&deptname');

Controlling User AccessControlling User Access


After completing this lesson, you After completing this lesson, you should be able to do the should be able to do the following:following: Create usersCreate users Create roles to ease setup and Create roles to ease setup and

maintenance of the security modelmaintenance of the security model Use the GRANT and REVOKE Use the GRANT and REVOKE

statements to grant and revoke statements to grant and revoke object privilegesobject privileges

After completing this lesson, you After completing this lesson, you should be able to do the should be able to do the following:following: Create usersCreate users Create roles to ease setup and Create roles to ease setup and

maintenance of the security modelmaintenance of the security model Use the GRANT and REVOKE Use the GRANT and REVOKE

statements to grant and revoke statements to grant and revoke object privilegesobject privileges

Controlling User AccessControlling User AccessControlling User AccessControlling User Access

DatabaseDatabaseadministratoradministrator

UsersUsers

Username and passwordprivileges

PrivilegesPrivilegesPrivilegesPrivileges Database security:Database security:

System securitySystem security Data securityData security

System privileges: Gain access to System privileges: Gain access to the databasethe database

Object privileges: Manipulate the Object privileges: Manipulate the content of the database objectscontent of the database objects

Schema: Collection of objects, such Schema: Collection of objects, such as tables, views, and sequencesas tables, views, and sequences

Database security:Database security: System securitySystem security Data securityData security

System privileges: Gain access to System privileges: Gain access to the databasethe database

Object privileges: Manipulate the Object privileges: Manipulate the content of the database objectscontent of the database objects

Schema: Collection of objects, such Schema: Collection of objects, such as tables, views, and sequencesas tables, views, and sequences

System PrivilegesSystem PrivilegesSystem PrivilegesSystem Privileges

More than 80 privileges are More than 80 privileges are available.available.

The DBA has high-level system The DBA has high-level system privileges:privileges: Create new usersCreate new users Remove usersRemove users Remove tablesRemove tables Back up tablesBack up tables

More than 80 privileges are More than 80 privileges are available.available.

The DBA has high-level system The DBA has high-level system privileges:privileges: Create new usersCreate new users Remove usersRemove users Remove tablesRemove tables Back up tablesBack up tables

Creating UsersCreating UsersCreating UsersCreating Users

The DBA creates users by using the The DBA creates users by using the CREATE USER statement.CREATE USER statement.

The DBA creates users by using the The DBA creates users by using the CREATE USER statement.CREATE USER statement.

SQL> CREATE USER scott 2 IDENTIFIED BY tiger;User created.User created.

SQL> CREATE USER scott 2 IDENTIFIED BY tiger;User created.User created.

CREATE USER user IDENTIFIED BY password;

User System User System PrivilegesPrivileges

User System User System PrivilegesPrivileges

GRANT privilege [, privilege...]TO user [, user...];

GRANT privilege [, privilege...]TO user [, user...];

• An application developer may have the following system privileges:– CREATE SESSION– CREATE TABLE– CREATE SEQUENCE– CREATE VIEW– CREATE PROCEDURE

• An application developer may have the following system privileges:– CREATE SESSION– CREATE TABLE– CREATE SEQUENCE– CREATE VIEW– CREATE PROCEDURE

• Once a user is created, the DBA can grant specific system privileges to a user.• Once a user is created, the DBA can grant

specific system privileges to a user.

Granting System Granting System PrivilegesPrivileges

Granting System Granting System PrivilegesPrivileges

The DBA can grant a user specific system The DBA can grant a user specific system privileges.privileges.

The DBA can grant a user specific system The DBA can grant a user specific system privileges.privileges.

SQL> GRANT create table, create sequence, create view 2 TO scott;Grant succeeded.Grant succeeded.

SQL> GRANT create table, create sequence, create view 2 TO scott;Grant succeeded.Grant succeeded.

What Is a Role?What Is a Role?What Is a Role?What Is a Role?

Allocating privilegesAllocating privilegeswithout a rolewithout a role

Allocating privilegesAllocating privilegeswith a rolewith a role

PrivilegesPrivileges

UsersUsers

ManagerManager

Creating and Granting Creating and Granting Privileges to a RolePrivileges to a Role

Creating and Granting Creating and Granting Privileges to a RolePrivileges to a Role

SQL> CREATE ROLE manager;Role created.Role created.

SQL> CREATE ROLE manager;Role created.Role created.

SQL> GRANT create table, create view 2 to manager; Grant succeeded.Grant succeeded.

SQL> GRANT create table, create view 2 to manager; Grant succeeded.Grant succeeded.

SQL> GRANT manager to BLAKE, CLARK; Grant succeeded.Grant succeeded.

SQL> GRANT manager to BLAKE, CLARK; Grant succeeded.Grant succeeded.

Changing Your PasswordChanging Your PasswordChanging Your PasswordChanging Your Password

The DBA creates your user account and The DBA creates your user account and initializes your password.initializes your password.

You can change your password by using You can change your password by using the ALTER USER statement.the ALTER USER statement.

The DBA creates your user account and The DBA creates your user account and initializes your password.initializes your password.

You can change your password by using You can change your password by using the ALTER USER statement.the ALTER USER statement.

SQL> ALTER USER scott 2 IDENTIFIED BY lion;User altered.User altered.

Object Privilege Table View Sequence

Procedure

ALTER

DELETE *

EXECUTE

INDEX *

INSERT *

REFERENCES *

SELECT *

UPDATE *

Object PrivilegesObject PrivilegesObject PrivilegesObject Privileges

Object PrivilegesObject PrivilegesObject PrivilegesObject Privileges

Object privileges vary from object to Object privileges vary from object to object.object.

An owner has all the privileges on the An owner has all the privileges on the object.object.

An owner can give specific privileges on An owner can give specific privileges on that owner’s object.that owner’s object.

Object privileges vary from object to Object privileges vary from object to object.object.

An owner has all the privileges on the An owner has all the privileges on the object.object.

An owner can give specific privileges on An owner can give specific privileges on that owner’s object.that owner’s object.

GRANT object_priv [(columns)] ON object TO {user|role|PUBLIC} [WITH GRANT OPTION];

GRANT object_priv [(columns)] ON object TO {user|role|PUBLIC} [WITH GRANT OPTION];

Granting Object Granting Object PrivilegesPrivileges

Granting Object Granting Object PrivilegesPrivileges

SQL> GRANT select 2 ON emp 3 TO sue, rich;Grant succeeded.Grant succeeded.

SQL> GRANT select 2 ON emp 3 TO sue, rich;Grant succeeded.Grant succeeded.

SQL> GRANT update (dname, loc) 2 ON dept 3 TO scott, manager;Grant succeeded.Grant succeeded.

SQL> GRANT update (dname, loc) 2 ON dept 3 TO scott, manager;Grant succeeded.Grant succeeded.

Grant query privileges on the EMP table.Grant query privileges on the EMP table. Grant query privileges on the EMP table.Grant query privileges on the EMP table.

• Grant privileges to update specific columns to users and roles. • Grant privileges to update specific

columns to users and roles.

Using WITH GRANT Using WITH GRANT OPTION and PUBLIC OPTION and PUBLIC

KeywordsKeywords

Using WITH GRANT Using WITH GRANT OPTION and PUBLIC OPTION and PUBLIC

KeywordsKeywords

Allow all users on the system to Allow all users on the system to query data from Alice’s DEPT query data from Alice’s DEPT table.table.

Allow all users on the system to Allow all users on the system to query data from Alice’s DEPT query data from Alice’s DEPT table.table.

SQL> GRANT select, insert 2 ON dept 3 TO scott 4 WITH GRANT OPTION;Grant succeeded.Grant succeeded.

SQL> GRANT select, insert 2 ON dept 3 TO scott 4 WITH GRANT OPTION;Grant succeeded.Grant succeeded.

SQL> GRANT select 2 ON alice.dept 3 TO PUBLIC;Grant succeeded.Grant succeeded.

SQL> GRANT select 2 ON alice.dept 3 TO PUBLIC;Grant succeeded.Grant succeeded.

• Give a user authority to pass along the privileges.• Give a user authority to pass along the

privileges.

Confirming Privileges Confirming Privileges GrantedGranted

Confirming Privileges Confirming Privileges GrantedGrantedData Dictionary Table Description

ROLE_SYS_PRIVS System privileges granted to roles

ROLE_TAB_PRIVS Table privileges granted to roles

USER_ROLE_PRIVS Roles accessible by the user

USER_TAB_PRIVS_MADE Object privileges granted on the user’s objects

USER_TAB_PRIVS_RECD Object privileges granted to the user

USER_COL_PRIVS_MADE Object privileges granted on the columns of the user’s objects

USER_COL_PRIVS_RECD Object privileges granted to the user on specific columns

How to Revoke Object How to Revoke Object PrivilegesPrivileges

How to Revoke Object How to Revoke Object PrivilegesPrivileges

You use the REVOKE statement to You use the REVOKE statement to revoke privileges granted to other revoke privileges granted to other users.users.

Privileges granted to others Privileges granted to others through the WITH GRANT OPTION through the WITH GRANT OPTION will also be revoked.will also be revoked.

You use the REVOKE statement to You use the REVOKE statement to revoke privileges granted to other revoke privileges granted to other users.users.

Privileges granted to others Privileges granted to others through the WITH GRANT OPTION through the WITH GRANT OPTION will also be revoked.will also be revoked.

REVOKE {privilege [, privilege...]|ALL}ON objectFROM {user[, user...]|role|PUBLIC}[CASCADE CONSTRAINTS];

REVOKE {privilege [, privilege...]|ALL}ON objectFROM {user[, user...]|role|PUBLIC}[CASCADE CONSTRAINTS];

Revoking Object Revoking Object PrivilegesPrivileges

Revoking Object Revoking Object PrivilegesPrivileges

As user Alice, revoke the As user Alice, revoke the SELECT and INSERT privileges SELECT and INSERT privileges given to user Scott on the DEPT given to user Scott on the DEPT table.table.

As user Alice, revoke the As user Alice, revoke the SELECT and INSERT privileges SELECT and INSERT privileges given to user Scott on the DEPT given to user Scott on the DEPT table.table.SQL> REVOKE select, insert

2 ON dept 3 FROM scott;Revoke succeeded.Revoke succeeded.

SQL> REVOKE select, insert 2 ON dept 3 FROM scott;Revoke succeeded.Revoke succeeded.

SummarySummarySummarySummary Statement Action

CREATE USER Allows the DBA to create a user

GRANT Allows the user to give other users

privileges to access the user’sobjects

CREATE ROLE Allows the DBA to create a collection

of privileges

ALTER USER Allows users to change theirpassword

REVOKE Removes privileges on an object from

users

Practice OverviewPractice OverviewPractice OverviewPractice Overview

Granting other users privileges to your tableGranting other users privileges to your table Modifying another user’s table through the privileges granted to youModifying another user’s table through the privileges granted to you Creating a synonymCreating a synonym Querying the data dictionary views related to privilegesQuerying the data dictionary views related to privileges

Granting other users privileges to your tableGranting other users privileges to your table Modifying another user’s table through the privileges granted to youModifying another user’s table through the privileges granted to you Creating a synonymCreating a synonym Querying the data dictionary views related to privilegesQuerying the data dictionary views related to privileges

displaying data from multiple tables (join ) sub queries creating sequences creating views

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