Is there any way how to invoke a PHP page / function when a record is inserted to a MySQL database table? We don't have control over the record insertion procedure. Is there a trigger mechanism which can call a PHP script back?
The trigger is executed on the MySQL server, not on the PHP one (even if those are both on the same machine).
So, I would say this is not quite possible -- at least not simply.
Still, considering this entry from the MySQL FAQ on Triggers :
23.5.11: Can triggers call an external application through a UDF?
Yes. For example, a trigger could invoke the
sys_exec()UDF available here: https://github.com/mysqludf/lib_mysqludf_sys#readme
So, there might be a way via an UDF function that would launch the php executable/script. Not that easy, but seems possible. ;-)
A friend and I have figured out how to call Bernardo Damele's sys_eval UDF, but the solution isn't as elegant as I'd like. Here's what we did:
Stored Procedure code:
DELIMITER $$ CREATE PROCEDURE udfwrapper_sp (p1 DOUBLE, p2 DOUBLE, p3 BIGINT) BEGIN DECLARE cmd CHAR(255); DECLARE result CHAR(255); SET cmd = CONCAT('C:/xampp/php/php.exe -f "C:/xampp/htdocs/phpFile.php" ', p1, ' ', p2, ' ', p3); SET result = sys_eval(cmd); END$$;
CREATE TRIGGER udfwrapper_trigger AFTER INSERT ON sometable FOR EACH ROW CALL udfwrapper_sp(NEW.Column1, NEW.Column2, NEW.Column3);
I'm not thrilled about having the stored procedure, and I don't know if it creates extra overhead, but it does work. Each time a row is added to sometable, the trigger fires.