Exit-when - iterative control, PL-SQL Programming

Assignment Help:

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 condition is true, the loop completes and controls the passes to the next statement after the loop. An illustration is as shown below:

LOOP
FETCH c1 INTO...
EXIT WHEN c1%NOTFOUND; -- exit loop if condition is true
...
END LOOP;
CLOSE c1;


Until the condition is true, the loop cannot complete. Thus, a statement inside the loop should change the value of the condition. In the last illustration, if the FETCH statement returns a row, then the condition is false. When the FETCH statement fails to return a row, then the condition is true, the loop completes, and then control passes to the CLOSE statement. The EXIT-WHEN statement replaces a simple IF statement. For illustration, compare the following statements as:



IF count > 100 THEN        | EXIT WHEN count > 100;
EXIT;                                   |
END IF;                               |


These statements are logically equal, but the EXIT-WHEN statement is easier to understand and read.


Related Discussions:- Exit-when - iterative control

Example of alternative formulation as a table constraint, Example of Altern...

Example of Alternative formulation as a table constraint Example: Alternative formulation as a table constraint ALTER TABLE EXAM_MARK ADD CONSTRAINT Must_be_enrolled_to_

Ending transactions, Ending Transactions A good quality programming pr...

Ending Transactions A good quality programming practice is to commit or roll back every transaction explicitly. Whether you rollback or issue the commit in your PL/SQL program

Theory of panspermia - origin of life, THEO R Y OF PANSPERMIA - Arrh...

THEO R Y OF PANSPERMIA - Arrhenius (1908) postulated the cosmic panspermia theory that claims that organisms existed throughout the universe, and their spores, etc., could

Subprograms, Subprograms The PL/SQL has two types of subprograms known ...

Subprograms The PL/SQL has two types of subprograms known as the procedures and functions that can take parameters and be invoked. As the following example represents, a subp

Special cases of projection, Special cases of projection This section ...

Special cases of projection This section describes the identity projection, r {ALL BUT}, and the projection on no attributes, r { }, which yields TABLE_DUM when r is empty, ot

Dynamic ranges- iterative control, Dynamic Ranges The PL/SQL lets you det...

Dynamic Ranges The PL/SQL lets you determine the loop range dynamically at run time, as the example below shows: SELECT COUNT(empno) INTO emp_count FROM emp; FOR i IN 1..emp_cou

Origin of earth - big bang hypothesis, ORIGIN OF EARTH - BIG-BAN G HY...

ORIGIN OF EARTH - BIG-BAN G HYPOTHESIS - Origin of life is linked to origin of earth. Cosmos, the Universe originated 10-20 billion years ago by Big Bang (thermonu

Transaction control, Transaction Control The Oracle is transaction orie...

Transaction Control The Oracle is transaction oriented; that is, Oracle uses the transactions to make sure the data integrity. The transaction is a sequence of SQL data manip

Example of delete - sql, Example of DELETE - SQL As with UPDATE, a FOR...

Example of DELETE - SQL As with UPDATE, a FOR PORTION OF clause can be specified if the target table has a defined period name, as illustrated in Example. Example: Deleting

%rowcount - implicit cursor attributes, %ROWCOUNT The %ROWCOUNT yields...

%ROWCOUNT The %ROWCOUNT yields the number of rows affected by the INSERT, UPDATE, or DELETE statement, or returned by a SELECT INTO statement. The %ROWCOUNT yields zero when a

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd