Question

I know there’s this statement ON UPDATE, is there a way to use it to create a column in my database and when this value change, another predefined value is set to 0 ?
Thanks in advance.

Exemple:

id | value | type
1      2      5
2      4      6
3      7      8

if i update the value of the first row, i want the type to set automaticaly to 0.

Answer 1

You need to create a trigger that gets executed for every time row changed, for example:

CREATE TRIGGER auto_update_type BEFORE UPDATE
ON your_table_name
FOR EACH ROW BEGIN

    if NEW.value <> OLD.value THEN
        SET NEW.type = 0;
    END IF;
END;

After this, for everytime you do query:

UPDATE table_name SET value = '10' WHERE id = 1;

If the value is different that the old one, trigger will gets executed and type will be set to 0

Here’s how to set trigger from phpMyAdmin: