MySql Cursor - Creating a procedure

André Alçada Padez picture André Alçada Padez · Jan 6, 2011 · Viewed 13.7k times · Source

i'm trying to create a cursor for the first time. I have looked at the documentation, i understand the concept, but i can't seem to get it to even be declared...

I'm using:

  • MySql 5.1.41
  • SqlYog as a manager
  • (running locally on a xampp instalation)

Even when copy pasting the example found in http://dev.mysql.com/doc/refman/5.1/en/cursors.html

    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 NOT FOUND SET done = 1;

  OPEN cur1;
  OPEN cur2;

  read_loop: LOOP
    FETCH cur1 INTO a, b;
    FETCH cur2 INTO c;
    IF done THEN
      LEAVE read_loop;
    END IF;
    IF b < c THEN
      INSERT INTO test.t3 VALUES (a,b);
    ELSE
      INSERT INTO test.t3 VALUES (a,c);
    END IF;
  END LOOP;

  CLOSE cur1;
  CLOSE cur2;
END;

I get errors right away: Error Code : 1064

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 3

and a bunch of others following,

this doesn't make any sense to me, can any kind soul help me please?

Thank you

So i got the sample query to work (thanks to ajreal), with resetting the DELIMITER. But when i run my query:

DELIMITER##
CREATE PROCEDURE RetiraPoints()
BEGIN
    DECLARE userid BIGINT;  
    DECLARE done INT DEFAULT 0;
    DECLARE cur CURSOR FOR SELECT uid FROM viewpoints;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
    OPEN cur;
    read_loop: LOOP 
    FETCH cur INTO userid;
        IF done THEN
            LEAVE read_loop;
        END IF;
        INSERT INTO points (iduser, points, pointcat) VALUES (uid, -1, 1), (userid, -1, 2), (userid, -1, 3), (userid, -1, 4), (userid, -1, 5), (userid, -1, 6);
    END LOOP;
    CLOSE cur;
END;##

i get: Error Code : 1064

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DECLARE done INT DEFAULT 0; DECLARE cur CURSOR FOR SELECT uid FROM viewpoints; ' at line 1

my god, this is hard...

Answer

ajreal picture ajreal · Jan 6, 2011

You forget to reset the delimiter to NOT ;

delimiter ##
...
end##

need to put a space right after delimiter

And the ending END does not require ;