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

Keyword & parameter description - expressions, Keyword & Parameter Descript...

Keyword & Parameter Description: boolean_expression: This is an expression which yields the Boolean value that is TRUE, FALSE, & NULL. character_expression: This

How transactions guard your database, How Transactions Guard Your Database ...

How Transactions Guard Your Database The transaction is a sequence of SQL data manipulation statements which does a logical unit of work. The Oracle treats the sequence of SQL

Declaring and initializing objects in pl/sql, Declaring and Initializing Ob...

Declaring and Initializing Objects: An object type is once defined and installed in the schema; you can use it to declare the objects in any PL/SQL, subprogram, block or packa

Effect of anonymous columns, Effect of Anonymous Columns Now, recall t...

Effect of Anonymous Columns Now, recall that a VALUES expression denotes a table with undefined column names. If an initial value is to be specified when a base table is creat

Example of null operator - nino rule, Example of Null operator - NiNo Rule ...

Example of Null operator - NiNo Rule If we wanted to make HIGHER_OF adhere to "NULL in, NULL out"-let's call it the NiNo rule-we would have to write something like what is sho

Parameter and keyword description - sql cursor, Parameter and Keyword Descr...

Parameter and Keyword Description: SQL: This SQL is the name of the implicit SQL cursor. %FOUND: This attribute results TRUE if an INSERT, DELETE, or UPDATE state

Using limit - collection method, Using LIMIT For nested tables, that h...

Using LIMIT For nested tables, that have no maximum size, the LIMIT returns NULL. For varrays, the LIMIT returns the maximum number of elements that a varray can have (that yo

Using host arrays - bulk bind performance improvement, Using Host Arrays ...

Using Host Arrays The Client-side programs can use anonymous PL/SQL blocks to bulk-bind input and output host arrays. However, this is the well-organized way to pass the colle

Data types in sql - timestamp, Data Types in SQL - Timestamp TIMESTAMP...

Data Types in SQL - Timestamp TIMESTAMP for values representing points in time on a specified uniform scale. DATE is used for timestamps on a scale of one day, such as DATE '2

Example of when or then constraints - sql, Example of WHEN or THEN Constrai...

Example of WHEN or THEN Constraints A concrete example showing how SQL supports WHEN/THEN constraints CREATE TABLE SAL_HISTORY (EmpNo CHAR (6), Salary INTEGER NOT NULL,

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