How to consolidate two sql server tables using Group By clause? - sql

Question

I have two tables TableA and TableB as follows:
TableA:
ItemID Qty Rate
-------- ----- --------
1 10 100.00
2 20 150.00
TableB:
ItemID Qty Rate
-------- ----- -------
1 5 150.00
3 10 200.00
3 20 400.00
Now I want to consolidate these two tables. My desired result needs to be as follows:
Result TableA:
ItemID Qty Rate
-------- ----- -------
1 15 150.00
2 20 150.00
3 30 400.00
I tried the following Insert Select statement, But it does not give the desired result.
INSERT INTO TableA
(
ItemID,
Qty,
Rate
)
SELECT
ItemID,
SUM(Qty),
MAX(Rate)
FROM
TableB
GROUP BY
ItemID
But it gives the result as follows:
ItemID Qty Rate
-------- ----- --------
1 10 100.00
2 20 150.00
1 5 150.00
3 30 400.00
How to achieve my desired result?
I tried like this:
MERGE PUR_PODetail AS Target
USING (
SELECT
#POID,
ItemID,
SUM(POQuantity),
MAX(UnitRate),
1,
CASE WHEN D1 = '' THEN NULL ELSE D1 END D1,
CASE WHEN D2 = '' THEN NULL ELSE D2 END D2,
CASE WHEN D3 = '' THEN NULL ELSE D3 END D3,
CASE WHEN RandomDimension = '' THEN NULL ELSE RandomDimension END RandomDimension,
0
FROM
#Detail
GROUP BY
ItemID, D1, D2, D3, RandomDimension
) AS Source ON (Target.ItemID = Source.ItemID) AND
(ISNULL(Target.D1, -999) = ISNULL(Source.D1, -999)) AND
(ISNULL(Target.D2, -999) = ISNULL(Source.D2, -999)) AND
(ISNULL(Target.D3, -999) = ISNULL(Source.D3, -999)) AND
(ISNULL(Target.RandomDimension, -999) = ISNULL(Source.RandomDimension, -999))
WHEN MATCHED
THEN UPDATE SET
Target.POQuantity = Target.POQuantity + Source.POQuantity,
Target.UnitRate = MAX(Source.UnitRate)
WHEN NOT MATCHED
INSERT
(
POID,
ItemID,
POQuantity,
UnitRate,
ItemStatusID,
D1,
D2,
D3,
RandomDimension,
EDInclusive_f
)
VALUES
(
#POID,
Source.ItemID,
Source.POQuantity,
Source.UnitRate,
1,
CASE WHEN Source.D1 = '' THEN NULL ELSE Source.D1 END D1,
CASE WHEN Source.D2 = '' THEN NULL ELSE Source.D2 END D2,
CASE WHEN Source.D3 = '' THEN NULL ELSE Source.D3 END D3,
CASE WHEN Source.RandomDimension = '' THEN NULL ELSE Source.RandomDimension END RandomDimension,
0
)
But it gives the following error.
Please correct the error. I dont know what would be wrong here.
Msg 102, Level 15, State 1, Procedure PUR_PurchaseOrder_IU, Line 936
Incorrect syntax near 'MERGE'.
Msg 156, Level 15, State 1, Procedure PUR_PurchaseOrder_IU, Line 953
Incorrect syntax near the keyword 'AS'.
But when I remove these merge statement from my stored procedure, it is executing...

Answer 1

You can't just use the INSERT statement for this, you have to either INSERTor UPDATEdepending on the ItemID already being present in your target table.
SQL Server 2005
UPDATE #TableA
SET Qty = a.Qty + b.Qty
, Rate = CASE WHEN a.Rate < b.Rate
THEN b.Rate
ELSE a.Rate
END
FROM #TableA a
INNER JOIN (
SELECT ItemID
, Qty = SUM(Qty)
, Rate = MAX(Rate)
FROM #TableB
GROUP BY
ItemID
) b ON a.ItemID = b.ItemID
INSERT INTO #TableA
SELECT ItemID, Qty, Rate
FROM ( SELECT ItemID
, Qty = SUM(Qty)
, Rate = MAX(Rate)
FROM #TableB b
WHERE NOT EXISTS (SELECT * FROM #TableA a WHERE a.ItemID = b.ItemID)
GROUP BY
ItemID
) b
SQL Server 2008 provides the MERGE statement for this.
Performs insert, update, or delete operations on a target table based on the results of a join with a source table. For example, you
can synchronize two tables by inserting, updating, or deleting rows in
one table based on differences found in the other table.
SQL Server 2008
MERGE #TableA AS Target
USING (
SELECT ItemID
, Qty = SUM(Qty)
, Rate = MAX(Rate)
FROM #TableB
GROUP BY
ItemID
) AS source (ItemID, Qty, Rate) ON (target.ItemID = source.ItemID)
WHEN MATCHED THEN
UPDATE SET target.Qty = target.Qty + source.Qty
, target.Rate = CASE WHEN target.Rate < source.Rate
THEN source.Rate
ELSE target.Rate
END
WHEN NOT MATCHED THEN
INSERT (ItemID, Qty, Rate)
VALUES (source.ItemID, source.Qty, source.Rate);

Answer 2

Try this one:
MERGE TableA T
USING
(
SELECT ItemId, SUM(Qty) Qty, MAX(Rate) Rate
FROM
(
SELECT ItemId, Qty, Rate from TableA
UNION ALL
SELECT ItemId, Qty, Rate from TableB
) S
ON T.ItemId = S.ItemId
WHEN MATCHED THEN UPDATE SET
Qty = S.Qty,
Rate= S.Rate
WHEN NOT MATCHED THEN
INSERT(ItemId, Qty, Rate)
VALUES(S.ItemId, S.Qty, S.Rate);

Answer 3

declare #t table (ItemID int,Qty int,Rate int)
insert into #t values (1,10,100),(2,20,150)
Select * from #t
declare #t1 table (ItemID int,Qty int,Rate int)
insert into #t1 values (1,5,150),(3,10,200),(3,20,400)
Select * from #t1
insert into #t
Select ItemID,sum(Qty) Qty,max(Rate) Rate from #t1 where ItemID not in (Select ItemID from #t)
group by ItemID
Select * from #t