select lender_libelle as Propriétaire, tdoc_libelle as Support, count(*) as Nombre from exemplaires left join lenders on expl_owner=idlender left join docs_type on expl_typdoc=idtyp_doc where expl_typdoc in (!!choixsupport!!) group by lender_libelle,tdoc_libelle order by lender_libelle,tdoc_libelle 