Question

I a MSAccess database which contains the following table

Table A

#

Column1    Column2    Amount
=======    =======    ======
Value1        Total+        100
Value1        Total-        -50
Value2        Total-        -233
Value2        Total+        +5

I want to be write a query that will give me distinct rows for the highest absolute amounts

Expected Results
Column1    Column2    Amount
=======    =======    ======
Value1         Total+     100
Value2         Total-     -233

Answer 1

This result set can be retrieved with the following query.

Column1 max_abs_value
Value1            100
Value2            233

SELECT
    Column1,
    Max(Abs(Amount)) AS max_abs_value
FROM Table_A
GROUP BY Column1;

Then, if you want to see the values of Column2 and Amount for those same rows, you can create a query which uses the first one as a subquery and which you join to Table_A.

SELECT
    a.Column1,
    a.Column2,
    a.Amount
FROM
    Table_A AS a
    INNER JOIN (
        SELECT
            Column1,
            Max(Abs(Amount)) AS max_abs_value
        FROM Table_A
        GROUP BY Column1
    ) AS sub
    ON a.Column1 = sub.Column1
WHERE
    Abs(Amount)=sub.max_abs_value;