Thank you for looking at my question,
I have three tables SO_Detail, PO_Detail and SO_vs_PO
SO_Detail has four columns of sales order data: SO_Date, SO_Number, SO_ItemNumber, SO_Qty
PO_Detail has four columns of purchase order data: PO_Date, PO_Number, PO_ItemNumber, PO_Qty
SO_vs_PO has two columns linking Sales Order and Purchase orders: SO_Number. PO_Number
I need to link the three tables in a query so that I can find which Sales Orders do not yet have Purchase Orders raised against them.