C# how to retrieve the top 10 repeated numbers from a column

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I have a winform with a access database. I need to retrieve the top 10 repeated numbers in a column. The code below give me the first 10 numbers in the column.

C#

private void btn_Top_10_Click(object sender, EventArgs e)
        {
            string queryString = "SELECT ListSheetID, Part FROM Post";
            queryString = "select top 10 ListSheetID,Part from Post";
            loadDataGrid(queryString);
        }

What I have tried:

The example above and a lot on looking and reading on the net.

Posted 20-Dec-17 10:16am

Member 12349103

Updated 20-Dec-17 10:37am

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an0ther1 · Accepted Answer · 2017-12-20T10:37:00

Quick and dirty method;

SQL

SELECT TOP 10 * FROM
    (SELECT ListSheetId, Part, COUNT(*) as RCount FROM Post GROUP BY ListSheetId, Part) AS MyTable
ORDER BY RCount DESC

Assume the following data
ListSheetId, Part
12, Wheel
10, Axle
1, Seat
12, Wheel
10, Axle
1, Seat
1, Seat
1, Seat
10, Axle
1, Seat
1, Seat
12, Wheel
12, Wheel
12, Wheel
1, Seat
1, Seat
1, Seat
1, Seat
1, Seat

How this works.
The Inner Query retrieves a list of ListSheetId, Part & a count of the number of Sheets & Parts
Result Set:
ListSheetId, Part, Count
12, Wheel, 5
10, Axle, 3
1, Seat, 11
The outer query retrieves the top 10 results after ordering the inner query by the Count column. If the above query was changed to SELECT TOP 2 then the result set would be;
ListSheetId, Part, Count
1, Seat, 11
12, Wheel, 5

Additional information;
GROUP BY creates distinct lists, assume the following data;
ListSheetId, Part, Count
12, Wheel, 5
10, Axle, 3
1, Seat, 11
12, Axle, 8
10, Seat, 4

If the above query was changed to SELECT TOP 4 then the result set would be;
ListSheetId, Part, Count
1, Seat, 11
12, Axle, 8
12, Wheel, 5
10, Seat, 4

This is because GROUP BY identifies the distinct values across all columns in the group by clause - NOTE: Count is not included as it is an aggregate method and is not included in the Group By clause.
Therefore 1 & Seat, 12 & Axle, 12 & Wheel & 10 & Seat are the first 4 distinct values after applying the Sort method

If this is not what you need please improve your question by adding example data & result sets

Kind Regards