Writing Executable Statements

Writing Executable Writing Executable StatementsStatements

Writing Executable Writing Executable StatementsStatements

THE PL/SQL EXECUTION ENVIRONMENTTHE PL/SQL EXECUTION ENVIRONMENT Wherever PL/SQL technology is required (i.e. in the RDBMS core or in its tools), Wherever PL/SQL technology is required (i.e. in the RDBMS core or in its tools), the PL/SQL engine accepts any valid PL/SQL block as input.the PL/SQL engine accepts any valid PL/SQL block as input.

PL/SQL in the Oracle Engine:PL/SQL in the Oracle Engine: The PL/SQL engine resides in the Oracle engine, the Oracle engine can The PL/SQL engine resides in the Oracle engine, the Oracle engine can process not only single SQL statements but also entire PL/SQL blocks.process not only single SQL statements but also entire PL/SQL blocks.

PL/SQL block of codeDECLARE

Procedural Statements,

BEGIN

Procedural Statements,

SQL statements;

EXCEPTIONS

SQL statements;

END;

PL/SQL Engine

SQL Statement Executor

Oracle Engine

Datatype ConversionDatatype ConversionDatatype ConversionDatatype Conversion

This statement produces a compilation This statement produces a compilation error if the variable v_date is declared as error if the variable v_date is declared as datatype DATE.datatype DATE.

This statement produces a compilation This statement produces a compilation error if the variable v_date is declared as error if the variable v_date is declared as datatype DATE.datatype DATE.

v_date := 'January 13, 1998'; v_date := 'January 13, 1998';

v_date := TO_DATE ('January 13, 1998', 'Month DD, YYYY');

v_date := TO_DATE ('January 13, 1998', 'Month DD, YYYY');

To correct the error, use the TO_DATE conversion function.To correct the error, use the TO_DATE conversion function.

Datatype ConversionDatatype ConversionDatatype ConversionDatatype Conversion

Convert data to comparable datatypes.Convert data to comparable datatypes. Mixed datatypes can result in an error Mixed datatypes can result in an error

and affect performance.and affect performance. Conversion functions:Conversion functions:

• TO_CHARTO_CHAR• TO_DATETO_DATE• TO_NUMBERTO_NUMBER

Convert data to comparable datatypes.Convert data to comparable datatypes. Mixed datatypes can result in an error Mixed datatypes can result in an error

and affect performance.and affect performance. Conversion functions:Conversion functions:

• TO_CHARTO_CHAR• TO_DATETO_DATE• TO_NUMBERTO_NUMBER

DECLARE v_date VARCHAR2(15);BEGIN SELECT TO_CHAR(hiredate,

'MON. DD, YYYY') INTO v_date FROM emp WHERE empno = 7839;END;

DECLARE v_date VARCHAR2(15);BEGIN SELECT TO_CHAR(hiredate,

'MON. DD, YYYY') INTO v_date FROM emp WHERE empno = 7839;END;

Nested Blocks Nested Blocks and Variable Scopeand Variable Scope


Statements can be nested wherever an Statements can be nested wherever an executable statement is allowed.executable statement is allowed.

A nested block becomes a statement.A nested block becomes a statement. An exception section can contain nested An exception section can contain nested

blocks.blocks. The scope of an object is the region of The scope of an object is the region of

the program that can refer to the object.the program that can refer to the object.

















An identifier is visible in the regions in An identifier is visible in the regions in which you can reference the which you can reference the unqualified identifier:unqualified identifier: A block can look up to the enclosing A block can look up to the enclosing

block.block. A block cannot look down to enclosed A block cannot look down to enclosed

blocks.blocks.

An identifier is visible in the regions in An identifier is visible in the regions in which you can reference the which you can reference the unqualified identifier:unqualified identifier: A block can look up to the enclosing A block can look up to the enclosing

block.block. A block cannot look down to enclosed A block cannot look down to enclosed

blocks.blocks.



... x BINARY_INTEGER;BEGIN ... DECLARE y NUMBER; BEGIN ... END; ...END;

Scope of x

Scope of y

ExampleExample

Operators in PL/SQLOperators in PL/SQLOperators in PL/SQLOperators in PL/SQL

LogicalLogical ArithmeticArithmetic Concatenation Concatenation Parentheses to Parentheses to

control order ofcontrol order ofoperationsoperations

Exponential operator (**)Exponential operator (**)

LogicalLogical ArithmeticArithmetic Concatenation Concatenation Parentheses to Parentheses to

control order ofcontrol order ofoperationsoperations

Exponential operator (**)Exponential operator (**)

Same as in SQL}}

ExamplesExamples Increment the index for a loop. Increment the index for a loop.

Set the value of a Boolean flag. Set the value of a Boolean flag.

Validate an employee number if it Validate an employee number if it contains a value.contains a value.

ExamplesExamples Increment the index for a loop. Increment the index for a loop.

Set the value of a Boolean flag. Set the value of a Boolean flag.

Validate an employee number if it Validate an employee number if it contains a value.contains a value.

Operators in PL/SQLOperators in PL/SQLOperators in PL/SQLOperators in PL/SQL

v_count := v_count + 1;v_count := v_count + 1;

v_equal := (v_n1 = v_n2);v_equal := (v_n1 = v_n2);

v_valid := (v_empno IS NOT NULL);v_valid := (v_empno IS NOT NULL);

Using Bind VariablesUsing Bind VariablesUsing Bind VariablesUsing Bind Variables

To reference a bind variable in PL/SQL, To reference a bind variable in PL/SQL, you must prefix its name with a colon (:).you must prefix its name with a colon (:).

ExampleExample

To reference a bind variable in PL/SQL, To reference a bind variable in PL/SQL, you must prefix its name with a colon (:).you must prefix its name with a colon (:).

ExampleExampleVARIABLE g_salary NUMBERDECLARE v_sal emp.sal%TYPE;BEGIN SELECT sal INTO v_sal FROM emp WHERE empno = 7369; :g_salary := v_sal;END;/

VARIABLE g_salary NUMBERDECLARE v_sal emp.sal%TYPE;BEGIN SELECT sal INTO v_sal FROM emp WHERE empno = 7369; :g_salary := v_sal;END;/

Code Naming ConventionsCode Naming ConventionsCode Naming ConventionsCode Naming Conventions

Avoid ambiguity:Avoid ambiguity: The names of local variables and formal The names of local variables and formal

parameters take precedence over the parameters take precedence over the names of database tables.names of database tables.

The names of columns take precedence The names of columns take precedence over the names of local variables.over the names of local variables.

Avoid ambiguity:Avoid ambiguity: The names of local variables and formal The names of local variables and formal

parameters take precedence over the parameters take precedence over the names of database tables.names of database tables.

The names of columns take precedence The names of columns take precedence over the names of local variables.over the names of local variables.

Indenting CodeIndenting CodeIndenting CodeIndenting Code

For clarity, indent each level of code.For clarity, indent each level of code. ExampleExample

For clarity, indent each level of code.For clarity, indent each level of code. ExampleExample

BEGIN IF x=0 THEN y:=1; END IF;END;

BEGIN IF x=0 THEN y:=1; END IF;END;

DECLARE v_deptno NUMBER(2); v_location VARCHAR2(13);BEGIN SELECT deptno, loc INTO v_deptno,

v_location FROM dept WHERE dname = 'SALES'; ...END;

DECLARE v_deptno NUMBER(2); v_location VARCHAR2(13);BEGIN SELECT deptno, loc INTO v_deptno,

v_location FROM dept WHERE dname = 'SALES'; ...END;

Determining Variable ScopeDetermining Variable ScopeDetermining Variable ScopeDetermining Variable Scope Class ExerciseClass Exercise Class ExerciseClass Exercise

...DECLAREV_SAL NUMBER(7,2) := 60000;V_COMM NUMBER(7,2) := V_SAL * .20;V_MESSAGE VARCHAR2(255) := ' eligible for commission';BEGIN ...

DECLARE V_SAL NUMBER(7,2) := 50000; V_COMM NUMBER(7,2) := 0; V_TOTAL_COMP NUMBER(7,2) := V_SAL + V_COMM; BEGIN ... V_MESSAGE := 'CLERK not'||V_MESSAGE; END;

V_MESSAGE := 'SALESMAN'||V_MESSAGE;END;

...DECLAREV_SAL NUMBER(7,2) := 60000;V_COMM NUMBER(7,2) := V_SAL * .20;V_MESSAGE VARCHAR2(255) := ' eligible for commission';BEGIN ...

DECLARE V_SAL NUMBER(7,2) := 50000; V_COMM NUMBER(7,2) := 0; V_TOTAL_COMP NUMBER(7,2) := V_SAL + V_COMM; BEGIN ... V_MESSAGE := 'CLERK not'||V_MESSAGE; END;

V_MESSAGE := 'SALESMAN'||V_MESSAGE;END;

Writing Control Writing Control StructuresStructures

Writing Control Writing Control StructuresStructures

Controlling PL/SQL Flow Controlling PL/SQL Flow of Executionof Execution

Controlling PL/SQL Flow Controlling PL/SQL Flow of Executionof Execution

You can change the logical flow of You can change the logical flow of statements using conditional IF statements using conditional IF statements and loop control statements and loop control structures. structures.

Conditional IFConditional IF statements: statements: IF-THEN-END IFIF-THEN-END IF IF-THEN-ELSE-END IFIF-THEN-ELSE-END IF IF-THEN-ELSIF-END IFIF-THEN-ELSIF-END IF

You can change the logical flow of You can change the logical flow of statements using conditional IF statements using conditional IF statements and loop control statements and loop control structures. structures.

Conditional IFConditional IF statements: statements: IF-THEN-END IFIF-THEN-END IF IF-THEN-ELSE-END IFIF-THEN-ELSE-END IF IF-THEN-ELSIF-END IFIF-THEN-ELSIF-END IF

IF StatementsIF StatementsIF StatementsIF Statements

IF condition THEN statements;[ELSIF condition THEN statements;][ELSE statements;]END IF;

IF condition THEN statements;[ELSIF condition THEN statements;][ELSE statements;]END IF;

SyntaxSyntax

Simple IF statement:Simple IF statement:

Set the manager ID to 22 if the employee Set the manager ID to 22 if the employee name is Osborne.name is Osborne.

SyntaxSyntax

Simple IF statement:Simple IF statement:

Set the manager ID to 22 if the employee Set the manager ID to 22 if the employee name is Osborne.name is Osborne.IF v_ename = 'OSBORNE' THEN v_mgr := 22;END IF;

IF v_ename = 'OSBORNE' THEN v_mgr := 22;END IF;

Simple IF StatementsSimple IF StatementsSimple IF StatementsSimple IF Statements

Set the job title to Salesman, the department number to 35, and the Set the job title to Salesman, the department number to 35, and the commission to 20% of the current salary if the last name is Miller.commission to 20% of the current salary if the last name is Miller.

ExampleExample

Set the job title to Salesman, the department number to 35, and the Set the job title to Salesman, the department number to 35, and the commission to 20% of the current salary if the last name is Miller.commission to 20% of the current salary if the last name is Miller.

ExampleExample

. . .IF v_ename = 'MILLER' THEN v_job := 'SALESMAN'; v_deptno := 35; v_new_comm := sal * 0.20; END IF;. . .

. . .IF v_ename = 'MILLER' THEN v_job := 'SALESMAN'; v_deptno := 35; v_new_comm := sal * 0.20; END IF;. . .

IF-THEN-ELSE Statement IF-THEN-ELSE Statement Execution FlowExecution Flow

IF-THEN-ELSE Statement IF-THEN-ELSE Statement Execution FlowExecution Flow

IF conditionIF conditionTRUETRUE

THEN actionsTHEN actions(including further IFs)(including further IFs)

THEN actionsTHEN actions(including further IFs)(including further IFs)

FALSEFALSE

ELSE actionsELSE actions(including further IFs)(including further IFs)

ELSE actionsELSE actions(including further IFs)(including further IFs)

IF-THEN-ELSE StatementsIF-THEN-ELSE StatementsIF-THEN-ELSE StatementsIF-THEN-ELSE Statements

Set a flag for orders where there are Set a flag for orders where there are fewer than five days between order fewer than five days between order date and ship date.date and ship date.

ExampleExample

Set a flag for orders where there are Set a flag for orders where there are fewer than five days between order fewer than five days between order date and ship date.date and ship date.

ExampleExample

...IF v_shipdate - v_orderdate < 5 THEN v_ship_flag := 'Acceptable';ELSE v_ship_flag := 'Unacceptable';END IF;...

...IF v_shipdate - v_orderdate < 5 THEN v_ship_flag := 'Acceptable';ELSE v_ship_flag := 'Unacceptable';END IF;...

IF-THEN-ELSIF IF-THEN-ELSIF Statement Execution FlowStatement Execution Flow

IF-THEN-ELSIF IF-THEN-ELSIF Statement Execution FlowStatement Execution Flow

IF conditionIF conditionIF conditionIF conditionTRUETRUE

THEN actionsTHEN actionsTHEN actionsTHEN actions

FALSEFALSE

ELSIFELSIFconditioncondition

ELSIFELSIFconditioncondition

TRUETRUE

THEN actionsTHEN actionsTHEN actionsTHEN actions

FALSEFALSE

ELSEELSEactionsactionsELSEELSE

actionsactions

IF-THEN-ELSIF StatementsIF-THEN-ELSIF StatementsIF-THEN-ELSIF StatementsIF-THEN-ELSIF Statements

For a given value, calculate a For a given value, calculate a percentage of that value based on a percentage of that value based on a condition.condition.

ExampleExample

For a given value, calculate a For a given value, calculate a percentage of that value based on a percentage of that value based on a condition.condition.

ExampleExample. . .IF v_start > 100 THEN v_start := 2 * v_start;ELSIF v_start >= 50 THEN v_start := .5 * v_start;ELSE v_start := .1 * v_start;END IF;. . .

. . .IF v_start > 100 THEN v_start := 2 * v_start;ELSIF v_start >= 50 THEN v_start := .5 * v_start;ELSE v_start := .1 * v_start;END IF;. . .

Building Logical ConditionsBuilding Logical ConditionsBuilding Logical ConditionsBuilding Logical Conditions

You can handle null values with the IS You can handle null values with the IS NULL operator.NULL operator.

Any arithmetic expression containing a Any arithmetic expression containing a null value evaluates to NULL.null value evaluates to NULL.

Concatenated expressions with null Concatenated expressions with null values treat null values as an empty values treat null values as an empty string.string.

You can handle null values with the IS You can handle null values with the IS NULL operator.NULL operator.

Any arithmetic expression containing a Any arithmetic expression containing a null value evaluates to NULL.null value evaluates to NULL.

Concatenated expressions with null Concatenated expressions with null values treat null values as an empty values treat null values as an empty string.string.

Logic TablesLogic TablesLogic TablesLogic Tables

Build a simple Boolean condition with Build a simple Boolean condition with a comparison operator.a comparison operator.

Build a simple Boolean condition with Build a simple Boolean condition with a comparison operator.a comparison operator.

NOT

TRUE

FALSE

NULL

OR

TRUE

FALSE

NULL

TRUE FALSE NULL

FALSE

TRUE

NULL

AND

TRUE

FALSE

NULL

TRUE FALSE NULL

TRUE

NULL NULL

NULL

FALSE FALSE

FALSE

FALSE

FALSE

TRUE

TRUE

TRUE

TRUETRUE

FALSE

NULL NULL

NULL

Iterative Control: LOOP Iterative Control: LOOP StatementsStatements

Iterative Control: LOOP Iterative Control: LOOP StatementsStatements

Loops repeat a statement or sequence Loops repeat a statement or sequence of statements multiple times.of statements multiple times.

There are three loop types:There are three loop types:• Basic loopBasic loop• FOR loopFOR loop• WHILE loopWHILE loop

Loops repeat a statement or sequence Loops repeat a statement or sequence of statements multiple times.of statements multiple times.

There are three loop types:There are three loop types:• Basic loopBasic loop• FOR loopFOR loop• WHILE loopWHILE loop

Basic LoopBasic LoopBasic LoopBasic Loop

SyntaxSyntax SyntaxSyntaxLOOP statement1; . . . EXIT [WHEN condition];END LOOP;

LOOP statement1; . . . EXIT [WHEN condition];END LOOP;

where: condition is a Boolean variable or expression (TRUE, FALSE, or NULL);

where: condition is a Boolean variable or expression (TRUE, FALSE, or NULL);

-- delimiter-- delimiter

-- statements-- statements

-- EXIT statement-- EXIT statement

-- delimiter-- delimiter

Basic LoopBasic LoopBasic LoopBasic Loop

DECLARE v_ordid item.ordid%TYPE := 601; v_counter NUMBER(2) := 1;BEGIN LOOP INSERT INTO item(ordid, itemid) VALUES(v_ordid, v_counter); v_counter := v_counter + 1; EXIT WHEN v_counter > 10; END LOOP;END;

DECLARE v_ordid item.ordid%TYPE := 601; v_counter NUMBER(2) := 1;BEGIN LOOP INSERT INTO item(ordid, itemid) VALUES(v_ordid, v_counter); v_counter := v_counter + 1; EXIT WHEN v_counter > 10; END LOOP;END;

ExampleExample ExampleExample

FOR LoopFOR LoopFOR LoopFOR Loop SyntaxSyntax

Use a FOR loop to shortcut the test for Use a FOR loop to shortcut the test for the number of iterations.the number of iterations.

Do not declare the index; it is declared Do not declare the index; it is declared implicitly.implicitly.

SyntaxSyntax

Use a FOR loop to shortcut the test for Use a FOR loop to shortcut the test for the number of iterations.the number of iterations.

Do not declare the index; it is declared Do not declare the index; it is declared implicitly.implicitly.

FOR counter in [REVERSE] lower_bound..upper_bound LOOP statement1; statement2; . . .END LOOP;

FOR counter in [REVERSE] lower_bound..upper_bound LOOP statement1; statement2; . . .END LOOP;

FOR LoopFOR LoopFOR LoopFOR Loop GuidelinesGuidelines

Reference the counter within the loop only; Reference the counter within the loop only; it is undefined outside the loop.it is undefined outside the loop.

Use an expression to reference the Use an expression to reference the existing value of a counter.existing value of a counter.

Do Do notnot reference the counter as the target reference the counter as the target of an assignment.of an assignment.

GuidelinesGuidelines Reference the counter within the loop only; Reference the counter within the loop only;

it is undefined outside the loop.it is undefined outside the loop. Use an expression to reference the Use an expression to reference the

existing value of a counter.existing value of a counter. Do Do notnot reference the counter as the target reference the counter as the target

of an assignment.of an assignment.

FOR LoopFOR LoopFOR LoopFOR Loop Insert the first 10 new line items for Insert the first 10 new line items for

order number 601.order number 601. ExampleExample

Insert the first 10 new line items for Insert the first 10 new line items for order number 601.order number 601.

ExampleExample

DECLARE v_ordid item.ordid%TYPE := 601;BEGIN FOR i IN 1..10 LOOP INSERT INTO item(ordid, itemid) VALUES(v_ordid, i); END LOOP;END;

DECLARE v_ordid item.ordid%TYPE := 601;BEGIN FOR i IN 1..10 LOOP INSERT INTO item(ordid, itemid) VALUES(v_ordid, i); END LOOP;END;

Nested Loops and LabelsNested Loops and LabelsNested Loops and LabelsNested Loops and Labels

...BEGIN <<Outer_loop>> LOOP v_counter := v_counter+1; EXIT WHEN v_counter>10; <<Inner_loop>> LOOP ... EXIT Outer_loop WHEN total_done = 'YES'; -- Leave both loops EXIT WHEN inner_done = 'YES'; -- Leave inner loop only ... END LOOP Inner_loop; ... END LOOP Outer_loop;END;

...BEGIN <<Outer_loop>> LOOP v_counter := v_counter+1; EXIT WHEN v_counter>10; <<Inner_loop>> LOOP ... EXIT Outer_loop WHEN total_done = 'YES'; -- Leave both loops EXIT WHEN inner_done = 'YES'; -- Leave inner loop only ... END LOOP Inner_loop; ... END LOOP Outer_loop;END;

Composite DatatypesComposite DatatypesComposite DatatypesComposite Datatypes

Types:Types:• PL/SQL RECORDSPL/SQL RECORDS• PL/SQL TABLESPL/SQL TABLES

Contain internal componentsContain internal components Are reusableAre reusable

Types:Types:• PL/SQL RECORDSPL/SQL RECORDS• PL/SQL TABLESPL/SQL TABLES

Contain internal componentsContain internal components Are reusableAre reusable

PL/SQL RecordsPL/SQL RecordsPL/SQL RecordsPL/SQL Records Must contain one or more components of Must contain one or more components of

any scalar, RECORD, or PL/SQL TABLE any scalar, RECORD, or PL/SQL TABLE datatype, called fieldsdatatype, called fields

Are similar in structure to records in a 3GLAre similar in structure to records in a 3GL Are not the same as rows in a database Are not the same as rows in a database

tabletable Treat a collection of fields as a logical unitTreat a collection of fields as a logical unit Are convenient for fetching a row of data Are convenient for fetching a row of data

from a table for processingfrom a table for processing

Must contain one or more components of Must contain one or more components of any scalar, RECORD, or PL/SQL TABLE any scalar, RECORD, or PL/SQL TABLE datatype, called fieldsdatatype, called fields

Are similar in structure to records in a 3GLAre similar in structure to records in a 3GL Are not the same as rows in a database Are not the same as rows in a database

tabletable Treat a collection of fields as a logical unitTreat a collection of fields as a logical unit Are convenient for fetching a row of data Are convenient for fetching a row of data

from a table for processingfrom a table for processing

Creating a PL/SQL RecordCreating a PL/SQL RecordCreating a PL/SQL RecordCreating a PL/SQL Record

SyntaxSyntax

Where Where field_declarationfield_declaration is is

SyntaxSyntax

Where Where field_declarationfield_declaration is is

TYPE type_name IS RECORD(field_declaration[, field_declaration]…);

identifier type_name;

TYPE type_name IS RECORD(field_declaration[, field_declaration]…);

identifier type_name;

field_name {field_type | variable%TYPE | table.column%TYPE | table%ROWTYPE} [[NOT NULL] {:= | DEFAULT} expr]

field_name {field_type | variable%TYPE | table.column%TYPE | table%ROWTYPE} [[NOT NULL] {:= | DEFAULT} expr]

Creating a PL/SQL RecordCreating a PL/SQL RecordCreating a PL/SQL RecordCreating a PL/SQL Record

Declare variables to store the name, job, Declare variables to store the name, job, and salary of a new employee.and salary of a new employee.

ExampleExample

Declare variables to store the name, job, Declare variables to store the name, job, and salary of a new employee.and salary of a new employee.

ExampleExample... TYPE emp_record_type IS RECORD (ename VARCHAR2(10), job VARCHAR2(9), sal NUMBER(7,2)); emp_record emp_record_type;...

... TYPE emp_record_type IS RECORD (ename VARCHAR2(10), job VARCHAR2(9), sal NUMBER(7,2)); emp_record emp_record_type;...

PL/SQL Record StructurePL/SQL Record StructurePL/SQL Record StructurePL/SQL Record Structure

Field1 (datatype)Field1 (datatype) Field2 (datatype) Field2 (datatype) Field3 (datatype) Field3 (datatype)

empno number(4) ename varchar2(10) job varchar2(9)

Field1 (datatype)Field1 (datatype) Field2 (datatype) Field2 (datatype) Field3 (datatype) Field3 (datatype)

ExampleExampleExampleExample

The %ROWTYPE AttributeThe %ROWTYPE AttributeThe %ROWTYPE AttributeThe %ROWTYPE Attribute

Declare a variable according to a Declare a variable according to a collection of columns in a database table collection of columns in a database table or view.or view.

Prefix %ROWTYPE with the database Prefix %ROWTYPE with the database table.table.

Fields in the record take their names and Fields in the record take their names and datatypes from the columns of the table datatypes from the columns of the table or view.or view.

Declare a variable according to a Declare a variable according to a collection of columns in a database table collection of columns in a database table or view.or view.

Prefix %ROWTYPE with the database Prefix %ROWTYPE with the database table.table.

Fields in the record take their names and Fields in the record take their names and datatypes from the columns of the table datatypes from the columns of the table or view.or view.

Advantages of Using Advantages of Using %ROWTYPE%ROWTYPE

Advantages of Using Advantages of Using %ROWTYPE%ROWTYPE

The number and datatypes of the The number and datatypes of the underlying database columns may not underlying database columns may not be known.be known.

The number and datatypes of the The number and datatypes of the underlying database column may underlying database column may change at runtime.change at runtime.

The attribute is useful when retrieving a The attribute is useful when retrieving a row with the SELECT statement.row with the SELECT statement.

The number and datatypes of the The number and datatypes of the underlying database columns may not underlying database columns may not be known.be known.

The number and datatypes of the The number and datatypes of the underlying database column may underlying database column may change at runtime.change at runtime.

The attribute is useful when retrieving a The attribute is useful when retrieving a row with the SELECT statement.row with the SELECT statement.

The %ROWTYPE AttributeThe %ROWTYPE AttributeThe %ROWTYPE AttributeThe %ROWTYPE Attribute

ExamplesExamples Declare a variable to store the same Declare a variable to store the same

information about a department as it information about a department as it is stored in the DEPT table. is stored in the DEPT table.

Declare a variable to store the same Declare a variable to store the same information about an employee as it is information about an employee as it is stored in the EMP table.stored in the EMP table.

ExamplesExamples Declare a variable to store the same Declare a variable to store the same

information about a department as it information about a department as it is stored in the DEPT table. is stored in the DEPT table.

Declare a variable to store the same Declare a variable to store the same information about an employee as it is information about an employee as it is stored in the EMP table.stored in the EMP table.

dept_record dept%ROWTYPE; dept_record dept%ROWTYPE;

emp_record emp%ROWTYPE; emp_record emp%ROWTYPE;

Creating a PL/SQL TableCreating a PL/SQL TableCreating a PL/SQL TableCreating a PL/SQL Table SyntaxSyntax SyntaxSyntaxTYPE type_name IS TABLE OF {column_type | variable%TYPE | table.column%TYPE} [NOT NULL] [INDEX BY BINARY_INTEGER];identifier type_name;

TYPE type_name IS TABLE OF {column_type | variable%TYPE | table.column%TYPE} [NOT NULL] [INDEX BY BINARY_INTEGER];identifier type_name;

...TYPE ename_table_type IS TABLE OF emp.ename%TYPE INDEX BY BINARY_INTEGER;ename_table ename_table_type;...

...TYPE ename_table_type IS TABLE OF emp.ename%TYPE INDEX BY BINARY_INTEGER;ename_table ename_table_type;...

ExampleExampleExampleExampleDeclare a PL/SQL variable to store a name.Declare a PL/SQL variable to store a name.Declare a PL/SQL variable to store a name.Declare a PL/SQL variable to store a name.

PL/SQL Table StructurePL/SQL Table StructurePL/SQL Table StructurePL/SQL Table Structure

Primary keyPrimary key ColumnColumn ...... ......

11 JonesJones 22 SmithSmith 33 MaduroMaduro

...... ......

BINARY_INTEGERBINARY_INTEGER ScalarScalar

Creating a PL/SQL TableCreating a PL/SQL TableCreating a PL/SQL TableCreating a PL/SQL Table

DECLARE TYPE ename_table_type IS TABLE OF emp.ename%TYPE INDEX BY BINARY_INTEGER; TYPE hiredate_table_type IS TABLE OF DATE INDEX BY BINARY_INTEGER; ename_table ename_table_type; hiredate_table hiredate_table_type;BEGIN ename_table(1) := 'CAMERON'; hiredate_table(8) := SYSDATE + 7; IF ename_table.EXISTS(1) THEN INSERT INTO ... ...END;

DECLARE TYPE ename_table_type IS TABLE OF emp.ename%TYPE INDEX BY BINARY_INTEGER; TYPE hiredate_table_type IS TABLE OF DATE INDEX BY BINARY_INTEGER; ename_table ename_table_type; hiredate_table hiredate_table_type;BEGIN ename_table(1) := 'CAMERON'; hiredate_table(8) := SYSDATE + 7; IF ename_table.EXISTS(1) THEN INSERT INTO ... ...END;

PL/SQL Table of RecordsPL/SQL Table of RecordsPL/SQL Table of RecordsPL/SQL Table of Records

• Define a TABLE variable with the %ROWTYPE attribute.

• Declare a PL/SQL variable to hold department information.

ExampleExample

• Define a TABLE variable with the %ROWTYPE attribute.

• Declare a PL/SQL variable to hold department information.

ExampleExampleDECLARE TYPE dept_table_type IS TABLE OF dept%ROWTYPE INDEX BY BINARY_INTEGER; dept_table dept_table_type; -- Each element of dept_table is a record

DECLARE TYPE dept_table_type IS TABLE OF dept%ROWTYPE INDEX BY BINARY_INTEGER; dept_table dept_table_type; -- Each element of dept_table is a record

Using PL/SQL Table MethodsUsing PL/SQL Table MethodsUsing PL/SQL Table MethodsUsing PL/SQL Table Methods

The following methods make The following methods make PL/SQL tables easier to use:PL/SQL tables easier to use: EXISTSEXISTS COUNTCOUNT FIRST and LASTFIRST and LAST PRIOR PRIOR

The following methods make The following methods make PL/SQL tables easier to use:PL/SQL tables easier to use: EXISTSEXISTS COUNTCOUNT FIRST and LASTFIRST and LAST PRIOR PRIOR

NEXTNEXT EXTENDEXTEND TRIMTRIM DELETEDELETE

NEXTNEXT EXTENDEXTEND TRIMTRIM DELETEDELETE

SummarySummarySummarySummary

Define and reference PL/SQL variables Define and reference PL/SQL variables of composite datatypes:of composite datatypes:• PL/SQL recordsPL/SQL records• PL/SQL tablesPL/SQL tables• PL/SQL table of recordsPL/SQL table of records

Define a PL/SQL record using the Define a PL/SQL record using the %ROWTYPE attribute.%ROWTYPE attribute.

Define and reference PL/SQL variables Define and reference PL/SQL variables of composite datatypes:of composite datatypes:• PL/SQL recordsPL/SQL records• PL/SQL tablesPL/SQL tables• PL/SQL table of recordsPL/SQL table of records

Define a PL/SQL record using the Define a PL/SQL record using the %ROWTYPE attribute.%ROWTYPE attribute.

Change the logical flow of statements Change the logical flow of statements by using control structures.by using control structures. Conditional (IF statement)Conditional (IF statement) Loops:Loops:

• Basic loopBasic loop• FOR loopFOR loop• WHILE loopWHILE loop• EXIT statementEXIT statement

Change the logical flow of statements Change the logical flow of statements by using control structures.by using control structures. Conditional (IF statement)Conditional (IF statement) Loops:Loops:

• Basic loopBasic loop• FOR loopFOR loop• WHILE loopWHILE loop• EXIT statementEXIT statement

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Writing Executable Statements