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From "Gentry, Michael \(Contractor\)" <>
Subject RE: MySql auto generated PK
Date Wed, 21 Jun 2006 16:32:49 GMT
Glad it is working the way you want.

I didn't pay that thread too much attention, but in general I prefer to
maintain my SQL schema scripts by hand rather than rely on a tool.
Especially after a schema is past the point of initial development.  I
just find it easier to put everything in a file (under version control)
so it is documented and has a history.


-----Original Message-----
From: Borut Bolcina [] 
Sent: Wednesday, June 21, 2006 12:16 PM
Subject: Re: MySql auto generated PK

I removed

It works! It starts inserting at 200 and takes 20 PKs in batches and 
then increment the correct value in AUTO_PK_SUPPORT table.

Where do I click to give you credits!?! ;-)

Thanks again,

P.S. What is your stand on (thread subject: MySql AUTO_PK_SUPPORT) the 
> I had a look at DbGenerator class. I think it would be nice if only 
> tables which do not already exist would be created. This way the 
> application which calls runGenerator() wouldn't throw 
> java.sql.SQLException: Table 'foo-bar' already exists. I know there is

> a constructor which accepts excludedEntities, but then the application

> have to check in advance if the tables are already there and pass 
> appropriate entities to the constructor. Of course one can always 
> catch the exception and make it quiet.

Gentry, Michael (Contractor) pravi:
> AUTO_PK_SUPPORT table is a Cayenne PK support table.  (It is not the
> MySQL way.)  If you were using Sybase, you'd also have an
> AUTO_PK_SUPPORT table created by Cayenne.
> The AUTO_INCREMENT is MySQL-only and I believe with Cayenne 1.2, you
> use it instead of AUTO_PK_SUPPORT.  The downside to AUTO_INCREMENT is
> that you can't cache keys or know the keys in advance (to build
> relationships), so this slows down INSERT and potentially UPDATE
> operations.  The upside to AUTO_INCREMENT is it is popular with many
> scripting languages (such as PHP) and if you are trying to interface a
> Cayenne-based application to an existing MySQL database, chances are
> they used AUTO_INCREMENT to generate primary keys.
> You shouldn't use AUTO_PK_SUPPORT and AUTO_INCREMENT on the same
> /dev/mrg
> -----Original Message-----
> From: Borut Bolcina [] 
> Sent: Wednesday, June 21, 2006 11:39 AM
> To:
> Subject: Re: MySql auto generated PK
> My MySql knowledge is less than desirable, so pardon me for asking...
> I thaught AUTO_PK_SUPPORT is the MySql way of auto incrementing 
> (together with AUTO_INCREMENT on column).
> Are you saying I don't even need AUTO_PK_SUPPORT table?
> -Borut
> Gentry, Michael (Contractor) pravi:
>> I didn't keep up with the MySQL stuff too much, but I believe support
>> was added (sometime in 1.2) for auto-increment columns.  The
>> isGenerated="true" is what controls it, I believe.  Assuming my
>> is working, that attribute tells Cayenne to not use the
>> table and instead rely on MySQL to auto-increment the value and
>> it to Cayenne.  
>> /dev/mrg
>> -----Original Message-----
>> From: Borut Bolcina [] 
>> Sent: Wednesday, June 21, 2006 2:53 AM
>> To:
>> Subject: MySql auto generated PK
>> Is something broken or am I missing something in my setup, but when 
>> inserting, Cayenne is generating PK instead of using AUTO_PK_SUPPORT.
>> I use Cayenne 1.2RC1, mysql-connector-java-3.1.13
>> This is mapping:
>> <db-attribute name="oid" type="INTEGER" isPrimaryKey="true" 
>> isGenerated="true" isMandatory="true"/>
>> and this is how I generate the tables
>> MySQLAdapter mysqlDbAdapter = new MySQLAdapter();
>> mysqlDbAdapter.setSupportsFkConstraints(true);
>> mysqlDbAdapter.setSupportsGeneratedKeys(true);
>> generator = new DbGenerator(mysqlDbAdapter, dataMap);
>> generator.setShouldCreatePKSupport(true);
>> generator.setShouldCreateFKConstraints(true);
>> generator.setShouldDropTables(false);
>> generator.runGenerator(dataSource);
>> AUTO_PK_SUPPORT table gets generated and correctly populated with
> table 
>> names and initial value 200.
>> When inserting records, Cayenne inserts records with PK 1,2,3,... 
> log 
>> files.
>> What did I miss. I think this worked months ago when exercising
> Cayenne 
>> with some simple examples.
>> Cheers,
>> Borut

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