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The IF statement is used to allow
conditional execution of one or more statements within a procedure. Scope | |
Procedures only SQL Syntax | |
IF Condition THEN [Statement;[...]] [ELSEIF Condition THEN [Statement; [...] ] ] [ELSE [Statement; [...] ] ] ENDIF; Parameters | |
- Condition
specifies anything that is allowed in
a search condition except
subqueries, column references, host
variables, dynamic parameters, aggregate functions, string functions,
date/time functions involving column references, long column functions,
or TID functions. Local
variables, built-in variables, and parameters may be included.
See the "Search Conditions" chapter for more information.
- Statement
is any statement allowed in a procedure,
including a compound statement. The statement may also be empty.
Description | |
IF statements can be nested. In a nested IF statement, each ELSE
is associated with the closest preceding IF.
Local variables, and parameters can be used anywhere a host variable would be allowed.
Each Statement may be a single simple statement, a compound
statement, or empty.
Authorization | |
Anyone can use the IF statement. Example | |
Create a procedure to enter orders into different tables according to the size of the order:
CREATE PROCEDURE OrderEntry (PartName CHAR(20) NOT NULL,
Quantity INTEGER NOT NULL) AS
BEGIN
IF :Quantity < 100 THEN
INSERT INTO SmallOrders
VALUES (:PartName, :Quantity);
ELSE
INSERT INTO LargeOrders
VALUES (:PartName, :Quantity);
ENDIF;
END
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Execute the procedure with different parameters. The first execution adds a row to the LargeOrders table.
EXECUTE PROCEDURE Reorder ('Widget', 1500)
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The second execution adds a row to the SmallOrders table.
EXECUTE PROCEDURE Reorder ('Widget', 15)
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