MySQL trigger after insert and after update

Question

I have two tables with one named att as follows

CREATE TABLE att (
  SID varchar(50) NOT NULL, 
  CID varchar(50) NOT NULL, 
  Date date NOT         


        

Answer 1

Make sure you change the delimiter before defining the trigger. Also make sure you're using the same table and column names when you create the table and the trigger (you're using att and attendance, and SID and StudID, in your examples).

As it is, the trigger definition caused no error when I tested it in MySQL 5.1.55 after setting the delimiter.

delimiter $$
CREATE TRIGGER `att_up` 
  AFTER UPDATE ON `attendance`
FOR EACH ROW 
BEGIN
  DECLARE Zeros INT;
  DECLARE Ones INT;
  DECLARE total INT;
  DECLARE attend FLOAT;
  SELECT SUM(8-(h1+h2+h3+h4+h5+h6+h7+h8)), 
         SUM(h1+h2+h3+h4+h5+h6+h7+h8),
         SUM(8-(h1+h2+h3+h4+h5+h6+h7+h8)) + SUM(h1+h2+h3+h4+h5+h6+h7+h8)
    INTO Zeros, Ones, Total FROM attendance 
    WHERE SID=NEW.SID;
  SET attend=((Zeros-Ones)/total)/100;
  INSERT INTO per (SID, CID, per) values (NEW.SID, NEW.CID, attend)
    ON DUPLICATE KEY UPDATE per=attend;
END$$
delimiter ;

Answer 2

DELIMITER $$

CREATE TRIGGER `att_up` AFTER UPDATE ON `attentance`
FOR EACH ROW

BEGIN

SET @zeros = 0;
SET @ones = 0;
SET @total = 0;
SET @atted = 0;


(SELECT (8-SUM(h1)+SUM(h2)+SUM(h3)+SUM(h4)+SUM(h5)+SUM(h6)+SUM(h7)+SUM(h8)) INTO @zeros FROM attentance WHERE StudID=NEW.StudID);
(SELECT SUM(h1+h2+h3+h4+h5+h6+h7+h8) INTO @ones FROM attentance WHERE StudID=NEW.StudID);
(SELECT (SUM(8-(h1+h2+h3+h4+h5+h6+h7+h8))+ SUM(h1+h2+h3+h4+h5+h6+h7+h8)) INTO @total FROM attentance WHERE StudID=NEW.StudID);

SELECT (((@zeros-@ones)/@total)/100) INTO @atted FROM (SELECT 1) AS x;

END$$