SQL Server: ORDER BY in subquery with UNION

Question

i have two queries being combined with a UNION ALL¹:

--Query 1
SELECT Flavor, Color
FROM Friends

 

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Answer 1

I know that you could use a CTE (Common Table Expression) , where you can use your order by for the CTE.

;with results as
(

    SELECT Cassettes.CassetteNumber,
    LastCassetteTransfers.Amount,
    CassetteTransfers.CreatedDate
    FROM Cassettes
    INNER JOIN LastCassetteTransfers
    ON Cassettes.CassetteGUID = LastCassetteTransfers.CassetteGUID

    UNION ALL

    SELECT Cassettes.CassetteNumber,
    (
       SELECT TOP 1 CassetteTransfers.Amount
       FROM CassetteTransfers
       WHERE CassetteTransfers.CassetteGUID = Cassettes.CassetteGUID
       AND CassetteTransfers.Mode = 'ctmLoad'
    ) AS Amount,
    CassetteTransfers.CreatedDate
    FROM Cassettes

)

SELECT CassetNumber, Amount
FROM results
ORDER BY CassetteTransfers.CreatedDate DESC, CassetteTransfers.Amount

That should help. The important thig is to make sure that you have your order by columns returned in the inner query (in this case the CTE).

Let me know how it works.