[Koha] SQL help please

I have this report that lists all the items in our QLD library but I want to restrict it to items ONLY held in our QLD library and not another branch... I don't know where to put the DISTINCT tag? Please advise: SELECT items.itemnumber, biblio.title, biblio.author, items.itemcallnumber, items.barcode FROM items LEFT JOIN biblio ON (items.biblionumber=biblio.biblionumber) WHERE items.homebranch='QLD' ORDER BY items.itemcallnumber Thanks for your help, Kerrie Stevens Harevst Bible College