How to combine multiple rows in MSSQL [duplicate]

Answer 1

Select T1.Id
    , Stuff(
        (
        Select ', ' + T2.Address
        From MyTable As T2
        Where T2.Id = T1.Id
        Order By T2.Address
        For Xml Path(''), type
        ).value('.', 'nvarchar(max)'), 1, 2, '') As Address
From MyTable As T1
Group By T1.Id

Answer 2

The Coalesce function can be used to produce that result. Coalesce returns the first non null value in a set. If you use it in the following manner it will recursivly return each value in order until it nulls out and return it as a comma delimited string. You can use any other delimiter if you want.

DECLARE @pAddr VarChar(MAX)
SELECT @pAddr = COALESCE(@pAddr + ', ', '') + [Address]
FROM AddressTable
WHERE AddressTable.Key = @pKey

You could put this code into a UDF, and then in a view simply call that UDF passing the key.