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From:Chris W Date:November 25 2007 7:09pm
Subject:Re: Incrementing a "Private" Integer Space
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Stut wrote:
>
> insert into test1 set p = 2, q = (select max(q) + 1 from test1 as tmp 
> where p = 2)
>
> Probably not very efficient, but it works.
>
> -Stut
>
Auto increment is much easier to do.  If your primary key is made up of 
two fields and one of them is Auto Increment, then it will have the 
desired behavior, just do this experiment and see....

CREATE TABLE  `t` (
 `p` int(10) unsigned NOT NULL default '0',
 `q` int(10) unsigned NOT NULL auto_increment,
 PRIMARY KEY  (`p`,`q`)
) ;

INSERT INTO `t` (`p`,`q`) VALUES
 (1,NULL),
 (1,NULL),
 (1,NULL),
 (2,NULL),
 (2,NULL),
 (2,NULL),
 (2,NULL),
 (2,NULL),
 (3,NULL),
 (3,NULL);

-- 
Chris W
KE5GIX

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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