mysql - Automatically update occurrences in another table

Question

I have two tables, one for storing reports of a user, and another for storing users.

1. Report_table
-----report_id(P)-----user_id--------
        001               


        

Answer 1

You need a trigger: http://dev.mysql.com/doc/refman/5.6/en/trigger-syntax.html which should fire after each insert operation on the reports_table.

CREATE TRIGGER update_report_cnt AFTER INSERT ON reports_table
FOR EACH ROW
   BEGIN
      UPDATE users_table SET no_of_reports = no_of_reports + 1 where user_id = NEW.user_id;
   END;

(I'm not sure the syntax is correct. Ithink a before insert trigger would also work)