I seem to have a problem with using the substring function in the where clause: Values "1102877, 61531668" vs "1102877, 6153166". Using the below I think I should have a match on above values.update #Combined_ReceiptTableset #Combined_ReceiptTable.jde_gross_qty = #JDE_ReceiptTable.jde_gross_qty, #Combined_ReceiptTable.jde_net_qty = #JDE_ReceiptTable.jde_net_qty, #Combined_ReceiptTable.gross_qty_diff = #Combined_ReceiptTable.ac2_gross_qty - #JDE_ReceiptTable.jde_gross_qty, #Combined_ReceiptTable.net_qty_diff = #Combined_ReceiptTable.ac2_net_qty - #JDE_ReceiptTable.jde_net_qtyfrom #Combined_ReceiptTable, #JDE_ReceiptTablewhere #Combined_ReceiptTable.trans_date = #JDE_ReceiptTable.jde_trans_date and #Combined_ReceiptTable.petroex_code = #JDE_ReceiptTable.jde_petroex_code and #Combined_ReceiptTable.tank_id = #JDE_ReceiptTable.jde_tank_id and substring(#Combined_ReceiptTable.ticket_no, 1, 16) = substring(#JDE_ReceiptTable.jde_ticket_no, 1, 16)