>I have a table that looks something like this:
>
>
>groupnum itemnum quantity
>1 10 1
>2 10 1
>1 17 5
>2 17 5
>1 23 2
>1 26 1
>2 26 1
>1 27 3
>2 27 4
>1 30 0
>2 30 0
>2 33 1
>1 36 3
>2 36 5
>
>
>The table isn't really sorted, but we order it this way in queries. As you can see, most itemnums are found in groups 1 and 2, and usually have the same quantity. The user wants a query that returns those itemnums found in both groups, but with different quantities. In the above example, such a query would return:
>
>
>1 27 3
>2 27 4
>1 36 3
>2 36 5
>
>There are probably a few ways to do this, involving sequences of queries, but I wonder what would be the most efficient.
Why would
1 17 5
2 17 5
not included ?
Cetin