LOOP#
Synopsis#
[label :] LOOP
statements
END LOOP
Description#
The LOOP
statement is an optional construct in SQL
routines to allow processing of a block of statements
repeatedly.
The block of statements
is processed until an explicit use of LEAVE
causes
processing to exit the loop. If processing reaches END LOOP
, another iteration
of processing from the beginning starts. LEAVE
statements are typically
wrapped in an IF
statement that declares a condition to stop the loop.
The optional label
before the LOOP
keyword can be used to name the
block.
Examples#
The following function counts up to 100
in a loop starting from the input
value i
and returns the number of incremental steps in the loop to get to
100
.
FUNCTION to_one_hundred(i int)
RETURNS int
BEGIN
DECLARE count int DEFAULT 0;
abc: LOOP
IF i >= 100 THEN
LEAVE abc;
END IF
SET count = count + 1;
SET i = i + 1;
END LOOP;
RETURN;
END
Further examples of varying complexity that cover usage of the LOOP
statement
in combination with other statements are available in the SQL routines examples
documentation.