Question

I have a MySQL db. When a field in a table is updated can I write a function or by some other process get a field in another table to be automatically updated?

ie, and this is what I want to do, if table 1 field discount_code and discount code is 123456, then in table 2 can I have times_code_can_be_used (starts at say 20) automatically reduced by 1???

Not done this before and need some guidance.

Thank you.

Answer 1

yes you can do it using mysql trigger

example :-

delimiter |

CREATE TRIGGER testref BEFORE INSERT ON test1
  FOR EACH ROW BEGIN
    INSERT INTO test2 SET a2 = NEW.a1;
    DELETE FROM test3 WHERE a3 = NEW.a1;
    UPDATE test4 SET b4 = b4 + 1 WHERE a4 = NEW.a1;
  END;
|

delimiter ;

Note :Support for triggers is included beginning with MySQL 5.0.2