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From Michael Watzek <mwa.t...@spree.de>
Subject Re: JPOX generated tablenames
Date Tue, 12 Jul 2005 13:18:42 GMT
Hi Andy,

I mixed up the max length of SQL92 identifiers: 128 is correct.

Regards,
Michael
>>I think, mangling of tablenames does only make sense in the case of
>>forward engineering when the orm metadata and the SQL schema are generated.
> 
> 
> Well, we could just throw a StupidUserException, or we could take remedial 
> action. Not part of the JDO spec so we can do as we please, and we have 
> plenty of other things to do right now.
> 
> 
>>Currently, you can see this phenomenon when you run the TCK: there are
>>about 5 errors "Table 'xxx' does not exist", e.g. the classname is
>>"HashtableStringKeyCollections", the orm metadata maps it to a tablename
>>"HASHTABLESTRINGKEY_COLLECTIONS" (this tablename is also used in the SQL
>>schema), but the JPOX generated tablename  name is
>>"HASHTABLESTRINGKEY_COLLET8".
> 
> 
> As I said yesterday I deleted the code that was limiting it to 25 characters, 
> so you get the full 30 with latest JPOX, with no mangling if your table name 
> is <= 30. So use latest JPOX if that is causing you problems
> 
> 
>>Another question: The Derby Reference Manual Version 10, June 11, 2005,
>>specifies that table names in Derby conform to SQL92 indentifiers. SQL92
>>identifiers have a max length of 192 unicode characters. So, I'm not
>>sure about the Derby restriction of 30 characters for identifiers which
>>you mention above.
> 
> 
> Derby's JDBC driver (10.0.2.1) returns that it supports 128 characters max for 
> table names, so how that signifies that it supports 192 characters I don't 
> know (probably the difference with the theory (the manual) and practice (the 
> code)). You refer to a particular version of Derby whereas JPOX attempts to 
> work with all versions of Cloudscape.
> 
> Where the 30 chars table name length in JPOX came from ? you need to ask Erik 
> since he added support for Cloudscape 10+ (aka Derby). I know that I *can* 
> create a table with name of length > 30, so removing the restriction of 30 
> seems possible, but maybe there's a reason? or maybe this was the limit in 
> Cloudscape 10 before being renamed to Derby ? If there's no good reason then 
> I'll remove the restriction.
> 
> 


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Michael Watzek                  Tech@Spree Engineering GmbH
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