Package body, PL-SQL Programming

The Package Body

The package specification is implemented by the package body. That is, the package body has the definition of every cursor and the subprogram declared in the package specification. Remember that the subprograms defined in the package body are available outside the package only if their specifications also show in the package specification. To match the subprogram specifications and bodies, the PL/SQL does a token-by-token comparison of their headers. Therefore, except for white space, the headers should match word for word. Or else, the PL/SQL raises an exception, as the illustration below shows:

CREATE PACKAGE emp_actions AS

...

PROCEDURE calc_bonus (date_hired emp.hiredate%TYPE, ...);

END emp_actions;

CREATE PACKAGE BODY emp_actions AS

...

PROCEDURE calc_bunus (date_hired DATE, ...) IS

-- parameter declaration raises an exception as 'DATE'

-- does not match 'emp.hiredate%TYPE' word for word

BEGIN ... END;

END emp_actions;

The package body can also contain the private declarations that define the types and items essential for the internal workings of the package. The scopes of these declarations are local to the package body. And hence, the declared types and items are unapproachable except from within the package body. Dissimilar the package specification, the declarative section of a package body can have the subprogram bodies.

The declarative section below of the package body is the optional initialization sections that typically hold the statements that initialize some of the variables formerly declared in the package.

The initialization section of the package plays a minor role as, dissimilar subprograms; the package cannot be called or passed parameters. As an outcome, the initialization section of the package is only run once, that is the first time you reference the package. Keep in mind that, if a package specification declares only constants, types, variables, exceptions, and call specifications, the package body is needless. Though, the body can still be used to initialize the items declared in the package specification.

Posted Date: 10/8/2012 1:08:52 AM | Location : United States







Related Discussions:- Package body, Assignment Help, Ask Question on Package body, Get Answer, Expert's Help, Package body Discussions

Write discussion on Package body
Your posts are moderated
Related Questions
Consider the schema for FreeChecking Bank, that we designed given below. Translate the given ER schema into SQL CREATE TABLE statements (indicating primary key, unique and foreign

EXIT-WHEN The EXIT-WHEN statement permits a loop to complete conditionally. Whenever the EXIT statement is encountered, the condition in the WHEN clause is computed. When the co

Implicit Cursor Attributes The Implicit cursor attributes returns the information about the execution of an INSERT, DELETE, UPDATE, or SELECT INTO statement. The cursor attribu

Use the RETURNING Clause Frequently, the application requires information about the row affected by a SQL operation, for illustration, to produce a report or take a subsequent

SQL Database: So, an SQL database is one whose symbols are organized into a collection of tables. Now, shows an SQL table as the current value of an SQL variable, ENROLMENT, b

BEGIN Parameter Description in pl sql: BEGIN: This keyword signals the beginning of the executable section of a PL/SQL block, that contains executable statements. The execut

IN OUT Mode An IN OUT parameter passes initial values to the subprogram being called and return efficient values to the caller. Within the subprogram, an IN OUT parameter acts

what is the use of declare keyword

Using Aliases The Select-list items fetched from a cursor related with the %ROWTYPE should have simple names or, if they are expressions, should have aliases. In the example bel

Anatomy of a Command Figure, showing a simple SQL command, is almost identical to its counterpart in the theory book. The only difference arises from the fact that SQL uses a