ASA SQL Reference
  SQL Statements

IF statement

Description 

Use this statement to control conditional execution of SQL statements.

Syntax 

IF search-condition THEN statement-list
[ ELSEIF { search-condition | operation-type } THEN statement-list ] ...
[ ELSE statement-list ]
END IF

Usage 

The IF statement is a control statement that allows you to conditionally execute the first list of SQL statements whose search-condition evaluates to TRUE. If no search-condition evaluates to TRUE, and an ELSE clause exists, the statement-list in the ELSE clause is executed.

Execution resumes at the first statement after the END IF.

Permissions 

None.

Side effects 

None.

See also 

BEGIN statement

Using Procedures, Triggers, and Batches

Standards and compatibility 

• SQL/92    Persistent Stored Module feature.

• SQL/99    Persistent Stored Module feature.

• Sybase    The Transact-SQL IF statement has a slightly different syntax.

Example 

The following procedure illustrates the use of the IF statement:

CREATE PROCEDURE TopCustomer (OUT TopCompany CHAR(35),                               OUT TopValue INT)
BEGIN
   DECLARE err_notfound EXCEPTION
   FOR SQLSTATE '02000';
   DECLARE curThisCust CURSOR FOR
   SELECT company_name, CAST(    sum(sales_order_items.quantity *
   product.unit_price) AS INTEGER) VALUE
   FROM customer
   LEFT OUTER JOIN sales_order
   LEFT OUTER JOIN sales_order_items
   LEFT OUTER JOIN product
   GROUP BY company_name;
   DECLARE ThisValue INT;
   DECLARE ThisCompany CHAR(35);
   SET TopValue = 0;
   OPEN curThisCust;
   CustomerLoop:
   LOOP
      FETCH NEXT curThisCust
      INTO ThisCompany, ThisValue;
      IF SQLSTATE = err_notfound THEN
         LEAVE CustomerLoop;
      END IF;
      IF ThisValue > TopValue THEN
         SET TopValue = ThisValue;
         SET TopCompany = ThisCompany;
      END IF;
   END LOOP CustomerLoop;
   CLOSE curThisCust;
END