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sql - Select multiple columns from a table, but group by one

The table name is "OrderDetails" and columns are given below:

OrderDetailID || ProductID || ProductName || OrderQuantity

I'm trying to select multiple columns and Group By ProductID while having SUM of OrderQuantity.

 Select ProductID,ProductName,OrderQuantity Sum(OrderQuantity)
 from OrderDetails Group By ProductID

But of course this code gives an error. I have to add other column names to group by, but that's not what I want and since my data has many items so results are unexpected that way.

Sample Data Query:

ProductID,ProductName,OrderQuantity from OrderDetails

Results are below:

 ProductID     ProductName    OrderQuantity
    1001          abc               5
    1002          abc               23    (ProductNames can be same)
    2002          xyz               8
    3004          ytp               15
    4001          aze               19
    1001          abc               7     (2nd row of same ProductID)

Expected result:

 ProductID     ProductName    OrderQuantity
    1001          abc               12    (group by productID while summing)
    1002          abc               23
    2002          xyz               8
    3004          ytp               15
    4001          aze               19

How do I select multiple columns and Group By ProductID column since ProductName is not unique?

While doing that, also get the sum of the OrderQuantity column.

See Question&Answers more detail:os

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1 Answer

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I use this trick to group by one column when I have a multiple columns selection:

SELECT MAX(id) AS id,
    Nume,
    MAX(intrare) AS intrare,
    MAX(iesire) AS iesire,
    MAX(intrare-iesire) AS stoc,
    MAX(data) AS data
FROM Produse
GROUP BY Nume
ORDER BY Nume

This works.


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