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 can 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 table. /dev/mrg -----Original Message----- From: Borut Bolcina [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 21, 2006 11:39 AM To: [email protected] 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 memory > is working, that attribute tells Cayenne to not use the AUTO_PK_SUPPORT > table and instead rely on MySQL to auto-increment the value and return > it to Cayenne. > > /dev/mrg > > > -----Original Message----- > From: Borut Bolcina [mailto:[EMAIL PROTECTED] > Sent: Wednesday, June 21, 2006 2:53 AM > To: [email protected] > 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,... > ignoring AUTO_PK_SUPPORT. No SELECT FROM AUTO_PK_SUPPORT happens in log > files. > > What did I miss. I think this worked months ago when exercising Cayenne > with some simple examples. > > Cheers, > Borut > >
