Hi there,

I have a problem getting the relations from mySQL database into Middlegen GUI tool (I want to generate then Hibernate mappings).

I searched through the forums but got no good answer to my problem: some say that using a different JDBC driver would help...

So I have a couple of questions:

1. When I declare an ANT task in my build file for Middlegen like the following:

<target name="middlegen.go" depends="common.init, middlegen.init,fail-if-no-xdoclet-1.2,check-driver-present,panic-if-driver-not-present"
description="Launch Middlegen tool">
<taskdef
name="middlegen"
classname="middlegen.MiddlegenTask"
classpathref="middlegen.path"
/>
<echo>Schema name ${database.schema}</echo>
<middlegen
appname="${name}"
prefsdir="${prefs.dir}"
gui="${gui}"
databaseurl="${database.url}"
initialContextFactory="${java.naming.factory.initial}"
providerURL="${java.naming.provider.url}"
datasourceJNDIName="${datasource.jndi.name}"
driver="${database.driver}"
username="${database.userid}"
password="${database.password}"
schema=""
>

<hibernate destination="${build.gen-src.dir}" package="${name}.hibernate" genXDocletTags="false" genIntergratedCompositeKeys="false" javaTypeMapper="middlegen.plugins.hibernate.HibernateJavaTypeMapper"/>
</middlegen>
<mkdir dir="${build.classes.dir}"/>
</target>

Do I have to declare EXPLICITLY in the Middlegen task the relations between my tables like it's been done in the airline example:


<middlegen
..............................
<!--many2many>
<tablea generate="true" name="persons"/>
<jointable name="reservations" generate="false"/>
<tableb generate="true" name="flights"/>
</many2many-->
..................................
</middlegen>

Or the proper JDBC driver SHOULD determine the relations itself from the database without any help of additional mappings in middlegen task?

2. If I don't have to define EXPLICITLY the relations between my tables in middlegen task in order to see relations in GUI (and I assume the hibernate task would then properly generate mappings), so HOW can I solve my problems with mySQL database?

For test purpose I adjusted airline example for using Hypersonic SQL and it worked fine: I could see the relations in the GUI.

Any help is appreciated.

Thanks in advance,

Igor.

Hi,

1) No - Middlegen uses the Constraints defined in the database to show the relationships. I am assuming you have the constraints defined.

2) MySQL is the most probmatic DB as I am getting questions about it regually. Normally it turns out to be a database JDBC driver issue - mainly using beta (non-stable) drivers. Look in this area first.

I would also read the forums since most users were able to solve the problem.

--David.

Thanks, David.

I got my question answered when I looked into the Supported Platforms -> Databases section at the http://boss.bekk.no/boss/middlegen/plat ... abase.html

Should've read that before!!!

trying to find a remedy to my problem I moved my database to the MSSQL Server 2000 and downloaded the appropriate JDBC driver com.microsoft.jdbc.sqlserver.SQLServerDriver
off Microsoft's site.

But I seem to have another problem so that Middlegen reports that could successfully connects to the database but cannot find any tables in it.

Here's my settings:

<property name="database.script.file" value="D:/Work/GWS/gws.proj/automated/gws.ddl"/>
<property name="database.driver.classpath" value="${middlegen.lib}"/>
<property name="database.driver.file" value="${middlegen.lib}/mssqlserver.jar"/>
<property name="database.driver" value="com.microsoft.jdbc.sqlserver.SQLServerDriver"/>
<property name="database.url" value="jdbc:microsoft:sqlserver://localhost:1433;databasename=gws"/>
<property name="database.userid" value="sa"/>
<property name="database.password" value=""/>
<property name="database.schema" value=""/>
<property name="database.catalog" value=""/>

<property name="jboss.datasource.mapping" value="MS SQLSERVER"/>
<!--property name="jboss.datasource.mapping" value="MS SQLSERVER2000"/-->

What could be wron with that? Do I have to specify a SCHEMA name AND/OR catalog?

Thanks in advance.

I use Oracle, MSSQL and develop Middlegen with HSQL. MSSQL (atleast my setup) requires Schema and Catelog. Setting up the JDBC driver on a new DB is almost always a troublesome step.

Thanks for help!

I was able to generate mappings with all the relations after I used mySQL 4.0.17.
It supports InnoDB by default, there's no need to even make changes to config file to set up mySQL using InnoDB.

The driver I used was in mysql-connector-java-3.0.0-beta-bin.jar that comes with Middlegen.

anyway, thanks for help.


Igor.

Gald you were able top work it out.

Cheers David.