Subprograms, PL-SQL Programming

What Are Subprograms?

The Subprograms are named PL/SQL blocks which can take parameters and be invoked. The PL/SQL has 2 types of subprograms known as the procedures and functions. Normally, you use a procedure to perform an action and a function to calculate a value. Similar to unnamed or anonymous PL/SQL blocks, the subprograms have a declarative section, an executable part, and an optional exception-handling part. The declarative part contains the declarations of types, constants, cursors, variables, exceptions, & nested subprograms. These items are cease to exist and local whenever you exit the subprogram. The executable section contains statements which assign control execution, values, and manipulate Oracle data. The exception-handling section contains exception handlers that deal with the exceptions raised during the execution.

Consider the procedure below named debit_account that debits a bank account:

PROCEDURE debit_account (acct_id INTEGER, amount REAL) IS

old_balance REAL;

new_balance REAL;

overdrawn EXCEPTION;

BEGIN

SELECT bal INTO old_balance FROM accts

WHERE acct_no = acct_id;

new_balance := old_balance - amount;

IF new_balance < 0 THEN

RAISE overdrawn;

ELSE

UPDATE accts SET bal = new_balance

WHERE acct_no = acct_id;

END IF;

EXCEPTION

WHEN overdrawn THEN

...

END debit_account;

When called or invoked, this procedures accept an account number and a debit sum. It uses the account number to select the account balance from the accounts database table. Then, it uses the debit quantity to calculate a new balance. If the new balance is less than 0, an exception is raised; or else, the bank account is updated.

Posted Date: 10/5/2012 5:21:31 AM | Location : United States







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

Write discussion on Subprograms
Your posts are moderated
Related Questions
When Are Constraints Checked Under the model constraints are conceptually checked at all statement boundaries (and only at statement boundaries). By default the same is true

Redeclaring Predefined Exceptions Keep in mind that, the PL/SQL declares predefined exceptions globally in the package STANDARD; Therefore you need not declare them yourself.

1- You can check attribute names from each table in DBF11 by running for example:  desc dbf11.Member;  desc dbf11.Agent;  desc dbf11.Producer; Because some attribute names in

Use Object Types and Collections The Collection types and object types increase your efficiency by allowing for the realistic data modeling. The Complex real-world entities an

3CX PBX sync Windows Service Project Description: !! You require access to a commercial version of the 3CX PBX system in order to be able to program the API !! !! You requ

ROWNUM The ROWNUM returns a number representing the order in which a row was selected from the table. The first row selected has a ROWNUM of 1; the second row has a ROWNUM of

Using ROLLBACK The ROLLBACK statements end the present transaction and undo any change made during the transaction. The Rolling back is helpful for two reasons. Firstly, if yo

Procedural Constraint Enforcement (Triggers) SQL has an alternative method of addressing database integrity, involving event-driven procedural code. The special procedures th

1. Create a procedure called TAX_COST_SP to accomplish the tax calculation task. Keep in mind that the state and subtotal values are inputs into the procedure and the procedure is

TTITLE and BTITLE are commands in Pl-SQL to control report headings and footers. This Ttitle & Btitle are mainly used on creating SQL*PLUS report. Ttitle is used for toptitle headi