That works perfectly if there are more that one values in the week field eg.
?Week[]=117&Week[]=217&expert=&submit=Submit
but if there is only one eg. ?Week[]=117&expert=&submit=Submit
it gives me this error:
SELECT Client.ID AS ClientID, Client.Title, Client.FirstName, Client.Surname FROM Client JOIN Request ON Client.ID=Request.ClientID JOIN Commissions ON Request.ID=Commissions.RequestID WHERE Request.TravelExpert LIKE ? AND Commissions.Week IN ?
You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '?' at line 1