MySQL表上的触发器

Question

Helllo, I have the following table Scores :

ID
Name
Value
Creation_date
Modification_date

I also have table Scores_History :

ID
Name
Value
Creation_date

What I need to do is to set a trigger, so when a row in table Scores is updated, it will store the old Name and Value inside the Scores_History table (create a new row).

Can someone help me to figure out the query, since nothing I tried is working.

Answer 1

You want something like this:

CREATE TRIGGER yourtrigger BEFORE UPDATE ON `Scores`
FOR EACH ROW
BEGIN
    INSERT INTO `Scores_History` (Name, Value, Creation_date) VALUES(OLD.Name, OLD.Value, OLD.Creation_date);
END $$
DELIMITER;

Docs: http://dev.mysql.com/doc/refman/5.0/en/trigger-syntax.html

Similar: MySQL Triggers insert into another table

Answer 2

Something like this, assuming the id column in scores_history is auto_increment:

DELIMITER $$

CREATE TRIGGER scores_bu
BEFORE UPDATE ON scores
FOR EACH ROW
BEGIN
   INSERT INTO scores_history (name, value, creation_date)
   VALUES (OLD.name, OLD.value, OLD.creation_date);
END$$

DELIMITER ;

Actually, you probably want the "creation_date" column to contain the current date and time, rather than the value from the scores table.

To get that behavior, modify the trigger to replace the reference to "OLD.creation_date" with a reference to "NOW()" .