Simple cursors are supported inside stored procedures and
functions. The syntax is as in embedded SQL. Cursors are
currently asensitive, read-only, and non-scrolling. Asensitive
means that the server may or may not make a copy of its result
table.
Cursors must be declared before declaring handlers, and
variables and conditions must be declared before declaring
either cursors or handlers.
Example:
CREATE PROCEDURE curdemo()
BEGIN
DECLARE done INT DEFAULT 0;
DECLARE a CHAR(16);
DECLARE b,c INT;
DECLARE cur1 CURSOR FOR SELECT id,data FROM test.t1;
DECLARE cur2 CURSOR FOR SELECT i FROM test.t2;
DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done = 1;
OPEN cur1;
OPEN cur2;
REPEAT
FETCH cur1 INTO a, b;
FETCH cur2 INTO c;
IF NOT done THEN
IF b < c THEN
INSERT INTO test.t3 VALUES (a,b);
ELSE
INSERT INTO test.t3 VALUES (a,c);
END IF;
END IF;
UNTIL done END REPEAT;
CLOSE cur1;
CLOSE cur2;
END
