A Procedure or function is a schema object that consists of a set of SQL statements and other PL/SQL constructs, grouped together, stored in the database, and executed as a unit to solve a specific problem or perform a set of related tasks. Procedures and functions permit the caller to provide parameters that can be input only, output only, or input and output values. Procedures and functions allow you to combine the ease and flexibility of SQL with the procedural functionality of a structured programming language.
CREATE OR REPLACE PROCEDURE award_bonus (emp_id NUMBER, bonus NUMBER) AS
commission REAL;
comm_missing EXCEPTION;
BEGIN -- executable part starts here
SELECT commission_pct / 100 INTO commission FROM employees WHERE employee_id = emp_id;
IF commission IS NULL THEN RAISE comm_missing;
ELSE
UPDATE employees SET salary = salary + bonus*commission
WHERE employee_id = emp_id;
END IF;
EXCEPTION -- exception-handling part starts here
WHEN comm_missing THEN
DBMS_OUTPUT.PUT_LINE('This employee does not receive a commission.');
commission := 0;
WHEN OTHERS THEN
NULL; -- for other exceptions do nothing
END award_bonus;
/
Calling procedure from a package or procedure:
CALL award_bonus(150, 400);
From SQL: EXECUTE award_bonus(150,400);
If there is a error while compiling a procedure then @ SQL prompt >> SHOW ERRORS PROCEDURE
To drop a procedure @ SQL prompt: drop procedure procedure_name;
