Oracle PL-SQL

IN,OUT,IN-OUT parameters.

Procedure Specification and Procedure Body.

PROCEDURE name (parameter list.....)

is

local variable declarations

BEGIN

Executable statements.

Exception.

exception handlers

end;

FUNCTION name (argument list .....) Return datatype is

local variable declarations

Begin

executable statements

Exception

execution handlers

End;

Function is called as part of an expression.

sal := calculate_sal ('a822');

procedure is called as a PL/SQL statement

calculate_bonus ('A822');

The two parts of package are PACKAGE SPECIFICATION & PACKAGE BODY. Package Specification contains declarations that are global to the packages and local to the schema.

Package Body contains actual procedures and local declaration of the procedures and cursor declarations.

The Same procedure name is repeated with parameters of different datatypes and parameters in different positions, varying number of parameters is called overloading of procedures.

e.g. DBMS_OUTPUT put_line

What is a package ? What are the advantages of packages ?

A cursor declared in a package specification is global and can be accessed by other procedures or procedures in a package.

A cursor declared in a procedure is local to the procedure that can not be accessed by other procedures.

a. PACKAGE NAME.PROCEDURE NAME (parameters);

variable := PACKAGE NAME.FUNCTION NAME (arguments);

EXEC SQL EXECUTE

b.

BEGIN

PACKAGE NAME.PROCEDURE NAME (parameters)

variable := PACKAGE NAME.FUNCTION NAME (arguments);

END;

END EXEC;

c. EXECUTE PACKAGE NAME.PROCEDURE if the procedures does not have any out/in-out parameters. A function can not be called.

User_objects, User_Source and User_error.

Form

Menu

Library

SELECT last_name, employee_id, manager_id, LEVEL

FROM employees

START WITH employee_id = 100

CONNECT BY PRIOR employee_id = manager_id

ORDER SIBLINGS BY last_name;