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From:David T. Ashley Date:November 25 2007 6:18am
Subject:Incrementing a "Private" Integer Space
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I have a table with two integer fields (call them p and q).

When I insert a record with a known p, I want to choose q to be one larger
than the largest q with that p.

What is the best and most efficient way to do this?

For example, let's say the table contains (p,q):

1,1
1,2
1,3
2,1
2,2
2,3
2.4
2,5
3,1
3,2

If I insert a new record with p=2, I would want to choose q to be 6.  But if
I insert a record with p=3, I would want to choose q to be 3.

Is there any alternative to locking the table, querying for max q with the
desired p, then inserting?

Thanks.

Thread
Incrementing a "Private" Integer SpaceDavid T. Ashley25 Nov
  • Re: Incrementing a "Private" Integer SpaceChris W25 Nov
  • Re: Incrementing a "Private" Integer SpaceStut25 Nov
    • Re: Incrementing a "Private" Integer SpaceDavid T. Ashley25 Nov
      • Re: Incrementing a "Private" Integer SpaceStut25 Nov
    • Re: Incrementing a "Private" Integer SpaceChris W25 Nov
      • Re: Incrementing a "Private" Integer SpaceDavid T. Ashley25 Nov
        • Re: Incrementing a "Private" Integer SpaceChris W25 Nov
        • RE: Incrementing a "Private" Integer SpaceMartin Gainty25 Nov
          • Re: Incrementing a "Private" Integer SpaceDavid T. Ashley25 Nov