![ Like a procedure, a function can accept multiple
parameters, and the data type of the return value
must be declared in the header of the function.
CREATE [OR REPLACE] FUNCTION <function_name>
(<parameter1_name> <mode> <data type>,
<parameter2_name> <mode> <data type>, ...)
RETURN <function return value data type> {AS|IS}
<Variable declarations>
BEGIN
Executable Commands
RETURN (return_value);
. . .
[EXCEPTION
Exception handlers]
END;
The general syntax of the RETURN statement is:
RETURN <expression>;
2](https://image.slidesharecdn.com/functions-190205065654/85/Function-in-PL-SQL-2-320.jpg)
Function in PL/SQL
- 1. Prof. Neeraj Bhargava Pooja Dixit Department of Computer Science School of Engineering & System Science MDS, University Ajmer, Rajasthan, India 1
- 2. Like a procedure, a function can accept multiple parameters, and the data type of the return value must be declared in the header of the function. CREATE [OR REPLACE] FUNCTION <function_name> (<parameter1_name> <mode> <data type>, <parameter2_name> <mode> <data type>, ...) RETURN <function return value data type> {AS|IS} <Variable declarations> BEGIN Executable Commands RETURN (return_value); . . . [EXCEPTION Exception handlers] END; The general syntax of the RETURN statement is: RETURN <expression>; 2
- 3. CREATE OR REPLACE FUNCTION RetrieveSalary RETURN NUMBER IS v_Salary NUMBER(10,2); BEGIN SELECT Salary INTO v_Salary FROM Employee WHERE EmployeeID = '01885'; RETURN v_Salary; END RetrieveSalary; / 3
- 4. SQL> @RetrieveSalary Function created. SQL> var v_SalaryOutput NUMBER; SQL> EXEC :v_SalaryOutput := RetrieveSalary; PL/SQL procedure successfully completed. SQL> print v_SalaryOutput; V_SALARYOUTPUT -------------- 16250 4
- 5. PL/SQL Example illustrates a function that has a single IN parameter and that returns a VARCHAR2 data type. CREATE OR REPLACE FUNCTION FullName (p_EmployeeID IN employee.EmployeeID%TYPE) RETURN VARCHAR2 IS v_FullName VARCHAR2(100); v_FirstName employee.FirstName%TYPE; v_MiddleName employee.MiddleName%TYPE; v_LastName employee.LastName%TYPE; BEGIN SELECT FirstName, MiddleName, LastName INTO v_FirstName, v_MiddleName, v_LastName FROM Employee WHERE EmployeeID = p_EmployeeID; 5
- 6. -- Store last name, comma and blank and first name to variable v_FullName := v_LastName||', '||v_FirstName; -- Check for existence of a middle name IF LENGTH(v_MiddleName) > 0 THEN v_FullName := v_FullName|| ' ' ||SUBSTR(v_MiddleName,1,1)||'.'; END IF; RETURN v_FullName; END FullName; / 6
- 7. A simple SELECT statement executed within SQL*Plus can return the full name for any employee identifier value as shown in PL/SQL Example. /* PL SQL Example 13.10 */ SQL> SELECT FullName('01885') 2 FROM Employee 3 WHERE EmployeeID = '01885'; FULLNAME('01885') ----------------------------------- Bock, Douglas B. 7
- 8. SQL> SELECT FullName(EmployeeID) 2 FROM Employee 3 ORDER BY FullName(EmployeeID); FULLNAME(EMPLOYEEID) ------------------------------------- Adams, Adam A. Barlow, William A. Becker, Robert B. Becker, Roberta G. Bock, Douglas B. ... more rows will display 8
- 9. As with the DROP PROCEDURE statement, the DROP FUNCTION <functionName> is also straight-forward. As with DROP PROCEDURE, the DROP FUNCTION statement is a DDL command that causes execution of an implicit commit prior to and immediately after the command. SQL> DROP FUNCTION FullName; Function dropped. 9