Trigger on SELECT

jrahma

Hi,

Is is possible to create a trigger ON SELECT in MySQL?

If not, any other way to do it?

Thanks,
Jassim

bradgrafelman

jrahma;11040029 wrote:
Is is possible to create a trigger ON SELECT in MySQL?

Based upon the following definition of a trigger (taken from this MySQL manual page), I'd say no, it is not possible:

A trigger is defined to activate when a statement inserts, updates, or deletes rows in the associated table.

jrahma;11040029 wrote:
If not, any other way to do it?

To do.. what, exactly? If you're trying to perform something automatically whenever a SELECT query is executed that matches some criteria... no, I don't think that's possible in MySQL. You'd have to implement that logic inside your application (which can range from very easy to very painful depending upon how well-architected that application is).

Weedpacket

Well, you can't attach triggers to SELECT queries, because SELECTs don't alter rows.

You wouldn't expect a SELECT to actually change anything, which limits the usefulness of a trigger anyway. Depends on what the trigger is supposed to do.

I suppose you could write a view that includes a computed field.

jrahma

what I want to do is the following..

I have a medical software and I want a trigger to add a row in the event log every time a user do a SELECT on specific patient files because of confidentiality.

Weedpacket

I don't know of any DBMS that does triggers on SELECT statements. It would be weird.
Maybe your application will have to do something.

jrahma

You're right.. I guess I will have to do it in the application level...

Thank you everyone