Productspecification
SELECT p.productid ,i.itemCode ,p.itemid ,p.serialNR ,p.detailname ,i.itemNameCommercial ,i.itemNameCommercialForeign FROM [product].[productSpecification] p LEFT JOIN wms.item i ON p.itemID = i.itemID LEFT JOIN (SELECT itemid ,SUM(quantity) quantity FROM [wms].[stockBalance] WHERE quantity > 0 GROUP BY itemid) s ON p.itemid = s.itemID