How to implement left join for the below sql.

Question

i need to perform left join between inventory table and purchase table and inventory table with sales table.
please let me know the syntax.
SELECT Tbl_ProductGroupMaster.ProdName, Tbl_ProductGroupMaster.UnitNam, Tbl_Inventory.CrDate, Tbl_Inventory.QtyOpStk, Tbl_Inventory.QtyClStk, Tbl_Inventory.ExcShortage, purchase.SumOfNUnit, sales.SumOfQty
FROM Tbl_ProductGroupMaster, Tbl_Inventory left join
[SELECT Tbl_PurchaseMain.idate as p_idate, Tbl_PurchaseSub.Proid as proid,
sum(Tbl_PurchaseSub.NUnit) AS SumOfNUnit
FROM Tbl_PurchaseMain, Tbl_PurchaseSub WHERE Tbl_PurchaseMain.GID=Tbl_PurchaseSub.gid
and format(cdate(Tbl_PurchaseMain.idate),'mm-dd-yyyy') between format(cdate('13-Sep-2009'),'mm-dd-yyyy') and
format(cdate('02-Oct-2009'),'mm-dd-yyyy') GROUP BY
Tbl_PurchaseMain.idate, Tbl_PurchaseSub.Proid]. AS purchase on (Tbl_Inventory.CrDate = purchase.p_idate)
left join
[SELECT Tbl_SalesMain.idate AS s_idate, Tbl_SalesSub.Proid, sum(Tbl_SalesSub.Qty) AS SumOfQty
FROM Tbl_SalesMain, Tbl_SalesSub
WHERE Tbl_SalesMain.SAID=Tbl_SalesSub.SAID And
format(cdate(Tbl_SalesMain.idate),'mm-dd-yyyy') Between format(cdate('13-Sep-2009'),'mm-dd-yyyy') And
format(cdate('02-Oct-2009'),'mm-dd-yyyy')
GROUP BY Tbl_SalesMain.idate, Tbl_SalesSub.Proid]. AS sales on (Tbl_Inventory.CrDate = sales.s_idate)
WHERE
Tbl_ProductGroupMaster.PROID=Tbl_Inventory.proid AND
Tbl_Inventory.PROID=purchase.proid and
Tbl_Inventory.PROID=sales.proid and
Tbl_Inventory.CrDate = '13-Sep-2009';
thanks,
Vinodh

Answer 1

Completely unstested as you haven't given much information but do you mean something like this?
WITH purchase
       AS (  SELECT   Tbl_PurchaseMain.idate AS p_idate,
                      Tbl_PurchaseSub.Proid AS proid,
                      SUM (Tbl_PurchaseSub.NUnit) AS SumOfNUnit
               FROM   Tbl_PurchaseMain, Tbl_PurchaseSub
              WHERE   Tbl_PurchaseMain.GID = Tbl_PurchaseSub.gid
                      AND format (cdate (Tbl_PurchaseMain.idate), 'mm-dd-yyyy') BETWEEN format (
                                                                                           cdate('13-Sep-2009'),
                                                                                           'mm-dd-yyyy'
                                                                                    AND  format (
                                                                                            cdate('02-Oct-2009'),
                                                                                            'mm-dd-yyyy'
           GROUP BY   Tbl_PurchaseMain.idate, Tbl_PurchaseSub.Proid),
    sales
       AS (  SELECT   Tbl_SalesMain.idate AS s_idate,
                      Tbl_SalesSub.Proid,
                      SUM (Tbl_SalesSub.Qty) AS SumOfQty
               FROM   Tbl_SalesMain, Tbl_SalesSub
              WHERE   Tbl_SalesMain.SAID = Tbl_SalesSub.SAID
                      AND format (cdate (Tbl_SalesMain.idate), 'mm-dd-yyyy') BETWEEN format (
                                                                                        cdate('13-Sep-2009'),
                                                                                        'mm-dd-yyyy'
                                                                                 AND  format (
                                                                                         cdate('02-Oct-2009'),
                                                                                         'mm-dd-yyyy'
           GROUP BY   Tbl_SalesMain.idate, Tbl_SalesSub.Proid)
SELECT   Tbl_ProductGroupMaster.ProdName,
         Tbl_ProductGroupMaster.UnitNam,
         Tbl_Inventory.CrDate,
         Tbl_Inventory.QtyOpStk,
         Tbl_Inventory.QtyClStk,
         Tbl_Inventory.ExcShortage,
         purchase.SumOfNUnit,
         sales.SumOfQty
FROM   Tbl_ProductGroupMaster,
       Tbl_Inventory LEFT OUTER JOIN purchase
                     ON Tbl_Inventory.CrDate = purchase.p_idate
                     LEFT OUTER JOIN sales
                     ON Tbl_Inventory.CrDate = sales.s_idate
WHERE Tbl_ProductGroupMaster.PROID = Tbl_Inventory.proid
AND   Tbl_Inventory.PROID = purchase.proid
AND   Tbl_Inventory.PROID = sales.proid
AND   Tbl_Inventory.CrDate = '13-Sep-2009';Cheers
Ben
http://www.munkyben.wordpress.com