WHILE statement
Repeat the execution of a list of statements while a condition is true.
This statement may only be used within a compound statement.
Syntax
[ label : ] WHILE cond DO
{ stmt ; } [...]
END WHILE [ label ]
Parameters
-
label
An optional label for the loop, which is unique amongst all labels for statements within which the
WHILEstatement is contained. The label can be used to LEAVE or ITERATE the loop. -
cond
Any expression evaluating to a
BOOLEAN. -
stmt
A SQL statement.
Examples
-- sum up all odd numbers from 1 through 10
> BEGIN
DECLARE sum INT DEFAULT 0;
DECLARE num INT DEFAULT 0;
sumNumbers: WHILE num < 10 DO
SET num = num + 1;
IF num % 2 = 0 THEN
ITERATE sumNumbers;
END IF;
SET sum = sum + num;
END WHILE sumNumbers;
VALUES (sum);
END;
25
-- Compare with the much more efficient relational computation:
> SELECT sum(num) FROM range(1, 10) AS t(num) WHERE num % 2 = 1;
25