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From Tobias SCHOESSLER <Tobias.Schoess...@unvienna.org>
Subject Re: Problems with MySql id type with AUTO_INCREMENT
Date Fri, 29 Sep 2006 13:51:39 GMT
Andrus, thanks a lot  you for looking into this.

That is quite a pile of bugs I am running into here. First this MySQL JDBC
driver bug returning java.lang.Long for any auto-increment column, then
cayenne treating 'INT UNSIGNED' as an Integer. Now issues with
org.apache.cayenne.access.jdbc.ColumnDescriptor and SQLTemplate.

To get this running for me I understand that I only have to pick the right
datatype for my PKs so all the bugs are bypassed. Looking at
http://dev.mysql.com/doc/refman/5.0/en/connector-j-reference-type-conversions.html
I thought BIGINT should be unambigiously treated as a java.lang.Long for
all bugs mentioned.

Actually it worked, I tried setting the PKs to mysql type BIGINT and the
test case mentioned below passes. So for the record this is a solution for
using AUTO_INCREMENT PK generation with cayenne 1.2 and MySQL.

But...

If you recall my ultimate goal was to use a setup in which MySql is used in
a Sequoia/CJDBC cluster - the reason I did not use AUTO_PK_SUPPORT as LOCK
was not supported by Sequoia ...

Connecting through the cjdbc/sequoia driver to the database above, again
breaks the test case. Sequoia returns java.lang.Integer for the BIGINT
column ... : -[

I guess this is rather something to address in a sequoia forum or is there
a chance you add a sequoia setup in your test cases?

thanks

Tobias



                                                                           
             Andrus Adamchik                                               
             <andrus@objectsty                                             
             le.org>                                                    To 
                                       cayenne-user@incubator.apache.org   
             Thursday, 28                                               cc 
             September 2006                                                
             17:44                                                 Subject 
                                       Re: Problems with MySql id type     
                                       with AUTO_INCREMENT                 
             Please respond to                                             
             cayenne-user@incu                                             
             bator.apache.org                                              
                                                                           
                                                                           
                                                                           




Just got some time to test it, and the problem seems to be in
org.apache.cayenne.access.jdbc.ColumnDescriptor constructor... It is
getting confused by MySQL ResultSetMetaData returning JDBC type for
such column as INTEGER.

I created a new Jira issue with description of this problem:

http://issues.apache.org/cayenne/browse/CAY-672

I'll commit a fix to 3.0, as 1.2 users can have some code relying on
the old behavior and we want to keep 1.2 stable.

Andrus


On Sep 26, 2006, at 7:11 AM, Tobias SCHOESSLER wrote:
> Andrus,
>
> I am referring to http://issues.apache.org/cayenne/browse/CAY-639
> and our
> discussion below.
>
> I am using cayenne 1.2.1 now. I mapped all AUTO_INCREMENTED primary
> keys of
> sql type unsigned int as BIG_INT in cayenne.
>
> Cayenne correctly returns DataObjects with a primary key of type
> Long when
> using SelectQuery, when creating new objects or using getToXXX
> navigation
> to retrieve the object .
>
> But when I use SQLTemplate to retrieve the same DataObject cayenne
> still
> returns a pk of type Integer ...
>
> These are my test cases:
>
>
>              public void testDocumentPkViaSelectQuery() {
>                   List<TldDocument> docList =
> dataContext.performQuery(new
> SelectQuery(TldDocument.class, null));
>                   assertEquals(Long.class,
> docList.get(0).getObjectId().getIdSnapshot().get
> (TldDocument.DOCUMENT_UID_PK_COLUMN).getClass());
>
>              }
>
>              public void testDocumentPkViaSQLTemplate() {
>
>                   String sqlSelect = " select * ";
>                   String sqlFrom = " from TLD_DOCUMENT doc ";
>
>                   SQLTemplate query = new SQLTemplate
> (TldDocument.class,
> sqlSelect + " " + sqlFrom);
>                   List<TldDocument> docList =
> dataContext.performQuery(query);
>
>                   assertEquals(Long.class,
> docList.get(0).getObjectId().getIdSnapshot().get
> (TldDocument.DOCUMENT_UID_PK_COLUMN).getClass());
>
>              }
>
> testDocumentPkViaSelectQuery passes.
>
> testDocumentPkViaSQLTemplate fails.
>
> thanks, regards
>
> Tobias.
>
>
>
>
>
>              Andrus Adamchik
>              <andrus@objectsty
>
> le.org>                                                    To
>                                        cayenne-
> user@incubator.apache.org
>              Tuesday,
> 29                                                cc
>              August 2006 15:35
>
> Subject
>                                        Re: Problems with MySql id type
>              Please respond to         with AUTO_INCREMENT
>              cayenne-user@incu
>              bator.apache.org
>
>
>
>
>
>
>
>
> I'd appreciate that.
>
> Andrus
>
>
> On Aug 29, 2006, at 5:31 PM, Tobias SCHOESSLER wrote:
>
>> ok, I got it. You want me to add a Jira entry for this? I never did
>> this
>> before ... : |
>>
>>
>>
>>
>>
>>
>>              Andrus Adamchik
>>              <andrus@objectsty
>>
>> le.org>                                                    To
>>                                        cayenne-
>> user@incubator.apache.org
>>              Tuesday,
>> 29                                                cc
>>              August 2006 15:19
>>
>> Subject
>>                                        Re: Problems with MySql id
>> type
>>              Please respond to         with AUTO_INCREMENT
>>              cayenne-user@incu
>>              bator.apache.org
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> On Aug 29, 2006, at 4:16 PM, Tobias SCHOESSLER wrote:
>>
>>> But still you are right there is a bug in mysql too. If the column
>>> type is
>>> INT and not INT UNSIGNED it should return java.lang.Integer but it
>>> returns
>>> java.lang.Long instead. This was my first observation.
>>
>> Still probably worth fixing the mapping to follow the docs.
>>
>>
>>> but why does cayenne need BIGINT mapping set for the column to
>>> retrieve it
>>> as a java.lang.Long? I understand that this is unrelated to the bug
>>> in the
>>> mysql jdbc driver mentioned above.
>>
>> This is simply a workaround for the bug. BIGINT has a default JDBC
>> mapping to java.lang.Long. So this consistently produced a Long
>> during select and when reading auto-incremented value via JDBC.
>>
>> Andrus
>>
>>
>>
>
>
>
>




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