Select top 1 from each group sql [ANSWERED]

Select top 1 from each group sql

Asked By: Jeffrey Grima
Originally Asked On: 2014-01-02 12:58:08
Asked Via: stackoverflow

I want to select the most popular menu item per location. Any suggestions??

SELECT a.City, a.ItemName, a.Quantity
    FROM
            (SELECT TOP 1
                    l.city AS City,
                    mi.name AS ItemName,
                    SUM(ft.quantity_sold) AS Quantity
            FROM
                    FactTable ft
                            JOIN MenuItem mi ON (ft.menuItemID = mi.ID)
                            JOIN Location l ON (ft.locationID = l.ID)
            ORDER BY
                    Quantity DESC
            GROUP BY
                    l.city, mi.name;
            ) AS a

He received 1 answers
eventually accepting:

xQbert’s answer to

Select top 1 from each group sql

Maybe this… get the maximum sum for each city and menu item name. Top returns 1 row not one row per group. you need to use the max aggregate to make this work the way you want.

you can’t double aggregate max(sum(Quantity)) so you have to either use a sub select, or use a CTE (common table expression). This is the subselect.

Select city, itemName, max(Quantity)
FROM (
            SELECT 
                    l.city AS City,
                    mi.name AS ItemName,
                    SUM(ft.quantity_sold) AS Quantity
            FROM
                    FactTable ft
                            JOIN MenuItem mi ON (ft.menuItemID = mi.ID)
                            JOIN Location l ON (ft.locationID = l.ID)
            GROUP BY
                    l.city, mi.name) sub
GROUP BY City, ItemName;

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All Answers For: Select top 1 from each group sql

xQbert’s answer to

Select top 1 from each group sql

Maybe this… get the maximum sum for each city and menu item name. Top returns 1 row not one row per group. you need to use the max aggregate to make this work the way you want.

you can’t double aggregate max(sum(Quantity)) so you have to either use a sub select, or use a CTE (common table expression). This is the subselect.

Select city, itemName, max(Quantity)
FROM (
            SELECT 
                    l.city AS City,
                    mi.name AS ItemName,
                    SUM(ft.quantity_sold) AS Quantity
            FROM
                    FactTable ft
                            JOIN MenuItem mi ON (ft.menuItemID = mi.ID)
                            JOIN Location l ON (ft.locationID = l.ID)
            GROUP BY
                    l.city, mi.name) sub
GROUP BY City, ItemName;

Of course, you should really check out the original question.

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