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From "Christian Stamm" <sta...@Mathematik.Uni-Marburg.de>
Subject RE: Question on using enums.
Date Fri, 25 Nov 2005 10:00:38 GMT
Hi,

thanks for the answer so far and sorry for the unprecise question.
I'd like to know how the SQL ENUM type is implemented.

http://dev.mysql.com/doc/refman/4.1/en/enum.html

i.e. a column in a database table is allowed to have only n values.
My problem is not so much on the java side, but rather how to express it
in  project-schema.xml.

mfg
Christian

Thomas Fischer wrote:
>
> Hi,
>
> Assuming you mean java.util.enumeration:
> As far as I know, enumerations are just an older version of
> java.util.iterator. You would not want to store the iterator in the DB,
> you
> usually store the underlying collection. This is in most cases modelled by
> other tables referenced by a foreign key, which can be accessed in Torque
> via a list.
> Should you need other collection types, they would have to be
> hand-modelled
> out of the list.
>
> Assuming you mean the new jdk 1.5 enum type:
> Sorry, JDK 1.5 specific features are not supported yet. You would have to
> provide a custom mapper which maps the enum e.g. to an int. You would
> probably do that best in a mapper class. Then, overload the getter and
> setter method in the DB object class to accept the enum type, and map them
> internally to the int value, which is then stored in the database.
> Deprecate the original getters and setters to prevent the user from using
> them (I would guess throwing exceptions in the original methods is no
> good,
> as they are needed internally by Torque).
>
>       Thomas
>
>
> "Christian Stamm" <stammi@Mathematik.Uni-Marburg.de> schrieb am 24.11.2005
> 21:24:13:
>
>> Hi,
>>
>> I didn't find any documentation on how to declare enumerations in
>> project-schema.xml. If anyone could post example, that would be fine.
>>
>> Consider this as a noob question, so examples on usage would be also
>> appreciated.
>>
>> thx
>> Christian Stamm
>>
>> P.S.: After working a little with torque, I'm absolutely impressed. Nice
>> work!
>>
>>
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>
>
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