Select distinct id  from tm_templates a,  tm_templates_to_categories b  where a.visible=1 and a.id = b.template_id and (a.keywords like '%education %' OR a.software_required REGEXP 'education' or a.keywords like '% %' OR a.software_required REGEXP '')  and adult=0 order by id desc <BR>Got error 'empty (sub)expression' from regexp