select * from gdc_cat_producten,mod_winkelform_btwcodes where proBtw=btwId and (proReferentienummer='merk' or proTitelfr like '%merk%' or proKoptekstfr like '%merk%' or proIdfr like '%merk%') and gdc_cat_producten.publiceren=1 order by gdc_cat_producten.volgnummer,proId