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From Andrus Adamchik <and...@objectstyle.org>
Subject Re: MySql AUTO_PK_SUPPORT
Date Sun, 23 Apr 2006 09:34:24 GMT

On Apr 23, 2006, at 1:21 PM, Borut BolĨina wrote:

> If I understand you correctly, the above algorithm would create a  
> statement
> DELETE FROM AUTO_PK_SUPPORT WHERE TABLE_NAME IN ('tableA',  
> 'tableB', 'tableC')
> but not, say, tableD, as it is already present (created before).
>
> In my case this pkDeleteString would look like (empty table names)
> DELETE FROM AUTO_PK_SUPPORT WHERE TABLE_NAME IN ('')
> INSERT INTO AUTO_PK_SUPPORT (TABLE_NAME, NEXT_ID) VALUES ('', 200)

Sorry, my first message and the correction that followed was a bit  
confusing. "DELETE FROM .." is not needed at all. You need to do a  
SELECT to see what's there, compare with the full entity list, and  
only insert the missing records.

Also see Mike's suggestion on how to figure out the right starting  
value. It may work as an alternative or an addition to the algorithm  
above.


> One "workaround" I can think of is to do a SELECT on  
> AUTO_PK_SUPPORT and if no error is thrown I must assume the table  
> exists, so I skip generator.runGenerator(dataSource); altogether.

This is not generic enough as you may end up with missing records if  
you added a few new tables since the last run (so AUTO_PK_SUPPORT is  
there, but its contents are incomplete).

Andrus
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