I want to have a trigger on a table, when a cell is updated it takes the current value and stores this in a audit table, for example:

table.data_change
id table primary_key column new_value old_value timestamp


But is it possible to also pass an admin_id/user_id from the application to the database along with the update SQL query?

The main reason for using triggers is to prevent round trips between the db and application servers.

Any suggestions?

If you create a trigger on a table with BEFORE UPDATE you can reference the NEW.fieldname and OLD.fieldname to get the value before and after the UPDATE. You can INSERT the OLD.fieldname value to your audit table.

As for the user_id, is this an internal username or the username that you are connecting to the database with? If it is the latter then you can user CURRENT_USER(). If it is the internal identifier then you can always add this as part of the table so that during the UPDATE statement you also include this user_id. You can again reference the NEW.user_id and OLD.user_id in your trigger code.

its an internal username, one that is stored in a user table. (not a mysql user).

Yeh I can see what you mean, e.g having a last_update_admin_id, and then passing the admin_id along with the update SQL.

This will work nicely, cheers.

I have put together some sample trigger code based on what you are looking for above. Check out MySQL – Triggers « IT Integrated Business Solutions

Looks good, thanks for the code.