GROUP BY to combine/concat a column

Question

Hi,
SELECT         tblFuelCostDetails.TripId, tblFuelCostDetails.PurchaseDate,
                tblPetrolPumps.PumpName+CONVERT(nvarchar(50), tblFuelCostDetails.Quantity) as Pump
FROM           tblPetrolPumps INNER JOIN
               tblFuelCostDetails ON tblPetrolPumps.PumpId = tblFuelCostDetails.PumpId
Above query output is
TripId    PurchaseDate      Pump
74          2014-01-16          N.R120.00
73          2014-01-15          N.R10.00
73          2014-01-15          Masranga12.00
I would like to my output like
TripId    PurchaseDate      Pump
74          2014-01-16          N.R120.00
73          2014-01-15          N.R10.00,Masranga12.00
I find some example from internet where they give solution on a single table, but i could not make it when tables join together.

Answer 1

You can achieve this using a STUFF keyword in SQL. Please see below.
DECLARE @PetrolPumps TABLE
TripID INT,
PurchaseDate Date,
Pump VARCHAR(20)
INSERT INTO @PetrolPumps VALUES(73, '2014/01/15', 'N.R10.00')
INSERT INTO @PetrolPumps VALUES(73, '2014/01/15', 'Masranga12.00')
INSERT INTO @PetrolPumps VALUES(74, '2014/01/16', 'N.R120.00')
SELECT DISTINCT TripID, PurchaseDate,
STUFF((SELECT ', '+Pump FROM @PetrolPumps P2 WHERE P1.TripID = P2.TripID AND P1.PurchaseDate = P2.PurchaseDate
FOR XML PATH('')),1,1,'') AS Pump
FROM @PetrolPumps P1
You can use the same logic on any number of tables. It would have been much easier if you have posted the DDL and some sample DML.
To use the same query use a CTE on the top of this query that has your regualr query. That will suffice your requirement.
;WITH CTE AS
SELECT         tblFuelCostDetails.TripId, tblFuelCostDetails.PurchaseDate,
                tblPetrolPumps.PumpName+CONVERT(nvarchar(50), tblFuelCostDetails.Quantity) as Pump
FROM           tblPetrolPumps INNER JOIN
tblFuelCostDetails ON tblPetrolPumps.PumpId = tblFuelCostDetails.PumpId
SELECT DISTINCT TripID, PurchaseDate,
    STUFF((SELECT ', '+Pump FROM CTE P2 WHERE P1.TripID = P2.TripID AND P1.PurchaseDate = P2.PurchaseDate
            FOR XML PATH('')),1,1,'') AS Pump
FROM CTE P1
Good Luck :). Visit
http://sqlsaga.com/sql-server/how-to-concatenate-rows-into-one-row-using-stuff/ for a detailed article on STUFF keyword.