Question

I have a WEBSITE table like so:

WEBSITE
web ID | url         | progress
-------------------------------
1      | example.com | 67

I have a PROGRESS table like so:

PROGRESS
progress id | linking website id | amount to increase
---------------------------------------------------
1           | 1                  | 60
2           | 1                  | 7

When a row is inserted into PROGRESS using INSERT INTO,

I use php and mysql to get the accumulative values FROM the PROGRESS table, and then store the new value into the progress value FROM the WEBSITE table.

HOWEVER…

I was wondering if I could use these triggers I’ve been hearing about to automatically sum up the new progress value and store it?

Is this possible?

Answer 1

You don’t really need to use a trigger, you can just add the progress to the existing row in website but if you wanted to try a trigger you can use the following

delimiter $$

CREATE TRIGGER progress_update AFTER INSERT ON `progress`
  FOR EACH ROW BEGIN
    UPDATE `website` SET `progress` = `progress` + NEW.ammount_to_increase WHERE web_ID = NEW.linking_website_id;
  END;
$$

delimiter ;

You can also find further information on the syntax and use of triggers in on the manual page 12.1.11. CREATE TRIGGER Syntax