Achieving ROW_NUMBER / PARTITION BY in MS Access

ms-access, ms-access-2010, sql

Solution

In many cases we can achieve a similar result by performing an unequal self-join on the table and aggregating the results. For example, for data in a table named [MyData]

Ino  TYPE      DOC
---  --------  ---
  1  1800xxc1  3a 
  2  1810xxc2  3b 
  3  1700xxc3  3c 
  4  1700xxc4  3a 
  5  1800xxc5  3a 
  6  1800xxc6  3a 
  7  1800xxc7  3b

the query

SELECT 
    t1.DOC,
    t1.TYPE,
    COUNT(*) AS [Ino Seq]
FROM 
    MyData AS t1
    INNER JOIN
    MyData AS t2
        ON t2.DOC = t1.DOC
            AND t2.Ino <= t1.Ino
GROUP BY
    t1.DOC,
    t1.TYPE
ORDER BY 1, 3

returns

DOC  TYPE      Ino Seq
---  --------  -------
3a   1800xxc1        1
3a   1700xxc4        2
3a   1800xxc5        3
3a   1800xxc6        4
3b   1810xxc2        1
3b   1800xxc7        2
3c   1700xxc3        1

Problem

How can you make use of "Row number over partition by" in MS access? I googled it, but couldn't find any information as to how one would go about doing this. I'm talking about this particular function, which assigns a sequential integer to each row within the partition of a result set: ``` RowNumber Over(Partition by city Order By EmployeeID) ``` My data looks like this: ``` DOC_TYPE Ino 3a 1800xxc1 3b 1810xxc2 3c 1700xxc3 3a 1700xxc4 3a 1800xxc5 3a 1800xxc6 3b 1800xxc7 ``` However, I need it to look like this: ``` DOC_TYPE Ino Seq 3a 1800xxc1 1 3a 1700xxc4 2 3a 1800xxc5 3 3a 1800xxc6 4 3b 1810xxc2 1 3b 1800xxc7 2 3c 1700xxc3 1 ``` This is my query: ``` SELECT t1.RT_TAXCODE, t1.INV_NO, COUNT(*) AS Sno FROM GroupByTAXCODE AS t1 INNER JOIN GroupByTAXCODE AS t2 ON (t2.RT_TAXCODE = t1.RT_TAXCODE) AND (t2.Inv_no <= t1.Inv_no) GROUP BY t1.RT_TAXCODE, t1.INV_NO HAVING COUNT(*)=1 ORDER BY 1, 3; ``` This is taking more time as f 30 seconds

Original source