>>Imagine situation we want to find MIN value. But we can do nothing just with value, we need ID of record that contains MIN value. In VFP I can write
>>SELECT MIN(MyNumber), ID_FIELD, category from Mytable group by category.
>>
>
>Actually, this would contain ID of record that contains *one of the records* that satisfies the MIN() condition. There may be only one record that has the MIN(mynumber), but there may be more.
>
>You would need to group by category and id_field to get the true MIN(mynumber).
>Since the lowest MIN(mynumber) of category+id_field will be the lowest MIN(mynumber) of category alone anyway, you use TOP to get the records with the lowest value of MIN(mynumber) from that group e.g.

>SELECT TOP 1 category, id_field, MIN(mynumber)
>  FROM mytable
>  GROUP BY category, id_field
>  ORDER BY 3

>
>If there is more than one record in the result set, then there is more that one category+id_field combination that has that MIN(mynumber).

Actually this will not help, because what if we need to select all categories? There is solution, however, that is not efficient, using sub-query. (IMHO VFP query in such case MUCH more efficient).