I have a many-to-many mapping between classes named User and Data. My code successfully retrieves a User object from the database. The next thing it tries to do is retrieve a set of Data objects associated with the User object. It calls the User object's getData method which returns a PeristentSet, as it should. The code then calls the PersistentSet's size method, which incorrectly returns zero.

Hibernate never issues a select or any other SQL to try to fetch the contents of the set. I must be doing something stupid! Here is the code that is calling this:


I've tried using an iterator to access the set, but still hibernate did not issue a select to get the contents of the set. What could I be doing that would make hibernate not issue any SQL or throw an exception?

Hibernate version: 3.3.1

Mapping documents:
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
<class name="edu.emory.cci.security.auth.User" table="user" catalog="auth">
<id name="key" type="java.lang.Long">
<column name="user_key" />
<generator class="identity" />
</id>
<property name="userId" type="java.lang.String" unique="true">
<column name="user_id" length="200" not-null="true">
<comment>The user's user ID.</comment>
</column>
</property>
<property name="name" type="java.lang.String">
<column name="user_name" length="80">
<comment>The user's name.</comment>
</column>
</property>
<set name="data" lazy="true" table="data_user">
<key column="user_key" />
<many-to-many column="data_key" class="edu.emory.cci.security.auth.Data" />
</set>
</class>
</hibernate-mapping>

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
<class catalog="auth" name="edu.emory.cci.security.auth.Data" table="data">
<id name="key" type="java.lang.Long">
<column name="data_key"/>
<generator class="identity"/>
</id>
<property generated="never" lazy="false" name="dataId" type="java.lang.String">
<column length="300" name="data_id" not-null="true">
<comment>The data id</comment>
</column>
</property>
<property generated="never" lazy="false" name="isDeleted" type="java.lang.String" insert="false">
<column length="1" name="is_deleted" not-null="true">
<comment>If T, the data_id is deleted. No physical delete is done.</comment>
</column>
</property>
<many-to-one lazy="proxy" name="submitter" class="edu.emory.cci.security.auth.User">
<column name="submitter">
<comment>User ID of submitter or deleter</comment>
</column>
</many-to-one>
<set name="users" inverse="true" table="data_user">
<key column="data_key" />
<many-to-many column="user_key" class="edu.emory.cci.security.auth.User"/>
</set>
</class>
</hibernate-mapping>

Name and version of the database you are using: MySQL 5.1

The generated SQL (show_sql=true):

Debug level Hibernate log excerpt:
1046 [main] DEBUG edu.emory.cci.security.auth.UserDAO - finding User instance with property: userId, value: taki557
1046 [main] DEBUG org.hibernate.jdbc.AbstractBatcher - about to open PreparedStatement (open PreparedStatements: 0, globally: 0)
1046 [main] DEBUG org.hibernate.jdbc.ConnectionManager - opening JDBC connection
1046 [main] DEBUG org.hibernate.SQL -
/*
from
User as model
where
model.userId= ? */ select
user0_.user_key as user1_0_,
user0_.user_id as user2_0_,
user0_.user_name as user3_0_
from
auth.user user0_
where
user0_.user_id=?
Hibernate:
/*
from
User as model
where
model.userId= ? */ select
user0_.user_key as user1_0_,
user0_.user_id as user2_0_,
user0_.user_name as user3_0_
from
auth.user user0_
where
user0_.user_id=?
1046 [main] DEBUG org.hibernate.jdbc.AbstractBatcher - about to open ResultSet (open ResultSets: 0, globally: 0)
1046 [main] DEBUG org.hibernate.loader.Loader - result row: EntityKey[edu.emory.cci.security.auth.User#3]
1046 [main] DEBUG org.hibernate.jdbc.AbstractBatcher - about to close ResultSet (open ResultSets: 1, globally: 1)
1046 [main] DEBUG org.hibernate.jdbc.AbstractBatcher - about to close PreparedStatement (open PreparedStatements: 1, globally: 1)
1046 [main] DEBUG org.hibernate.engine.StatefulPersistenceContext - initializing non-lazy collections
1046 [main] DEBUG org.hibernate.jdbc.ConnectionManager - aggressively releasing JDBC connection
1046 [main] DEBUG org.hibernate.jdbc.ConnectionManager - releasing JDBC connection [ (open PreparedStatements: 0, globally: 0) (open ResultSets: 0, globally: 0)]
1046 [main] DEBUG edu.emory.cci.security.auth.AuthorizationTest - Getting data for new,new user

Try setting lazy to "false", for the set.

LinHib.

I've tried with lazy set to true or false. It made do difference. Hibernat did not issue a select to get the contents of the set.

The only suspicious thing that I see is userManager.findByUserId(userId3). Change the test-case in the way that the 'user3' is created via session.load(User.class, userId3) and check the result. I believe the test-case is passed then.

The set in User maps to "data_user", where as the Data class maps to "data" table. Is this intentional?

LinHib.