>>>I'm looking for a way to speed up a calculation routine that computes the total of a document that can contain up to a few hundred lines. The routine is slow now because for each line I access the db. I'm looking for a way to implement this in a more data oriented way.
>>>
>>>In VFP I would have dumped the relevant keys into a cursor and then join the tables to the cursor in an sql statement.
>>>
>>>I could of course simulate this by dumping the keys into a temporary table (which if I'm right would not limit the amount of times I access the db), but I was wondering if there is not a more "elegant" way to do this.
>>>
>>>TIA.
>>
>>I'm not sure I understand you right, but you could use derived tables in your SELECT.
>>

>>SELECT .....
>>FROM MainTable
>>INNER JOIN (SELECT Keys From SomeTable WHERE ...) DympedKeys
>>   ON ....
>>

>
>Right Borislav, I'm sorry, I was not explicit. I'm not working in VFP, but in vb.net. And my keys are for the time being stored in some sort of datatable in memory.
>The problem of speed is relevant because I need to recompute the totals each time the user enters or changes a field in the document.

I saw you posted in NET forum, so I expected that.
But the code I gave you is pure SQL code, it is not Front end related, and it can be executed no matter what DB is used.
The only drawback is that you have these keys in memory.
Could you build your SELECT on the fly and concatenate these keys?
(pseudo code)

String cStr = "SELECT  ..... FROM MainTable WHERE Key IN ("
loop for each key you have in memory
     cStr = cStr + Key.ToString() + ","
endloop
cStr = LEFT(cStr, LEN(cStr)-1)+")" && This is a VFP code, you should translate it to VB.NET :-)

execute cStr