This ois the error±
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '', '7 AND groepen.Groepnaam = 'Architect' GROUP BY Bedrijfsnaam ORDER BY Bedrijf' at line 1
And this the query±
if($_GET['categorien'] != "")
$sql = "SELECT * FROM klantgegevens INNER JOIN rubrieken ON klantgegevens.Rubriek = rubrieken.RubriekID INNER JOIN groepen on rubrieken.GroepID = groepen.GroepID WHERE ".$bedrijfsnaam." ".$provincie." AND Rubriek = ".$categorien." AND groepen.Groepnaam = 'Architect' GROUP BY Bedrijfsnaam ORDER BY Bedrijfsnaam LIMIT ".($page*$numresults).", ".$numresults." ";
I forgot to mention that it only goes wrong if i do a search with more than 1 categories. If i search on 2 categories together with an provincie than i get this error