Relations

[Slavko Glisic]

Please, can any one help me to resolve this relation:

I have Classroom class:

public class Classroom {

private Integer classroomId;
private String name;
private Set classes;
 
/**
 * @return Returns the classes.
 */
public Set getClasses() {
return classes;
}
/**
 * @param classes The classes to set.
 */
public void setClasses(Set classes) {
this.classes = classes;
}
/**
 * @return Returns the classroomId.
 */
public Integer getClassroomId() {
return classroomId;
}
/**
 * @param classroomId The classroomId to set.
 */
public void setClassroomId(Integer classroomId) {
this.classroomId = classroomId;
}
/**
 * @return Returns the name.
 */
public String getName() {
return name;
}
/**
 * @param name The name to set.
 */
public void setName(String name) {
this.name = name;
}
}
 

and Class_ class:

public class Class_ {
private Integer classId;
private String name;
private Classroom classroom;
 
/**
 * @return Returns the classId.
 */
public Integer getClassId() {
return classId;
}
/**
 * @param classId The classId to set.
 */
public void setClassId(Integer classId) {
this.classId = classId;
}
/**
 * @return Returns the classroom.
 */
public Classroom getClassroom() {
return classroom;
}
/**
 * @param classroom The classroom to set.
 */
public void setClassroom(Classroom classroom) {
this.classroom = classroom;
}
/**
 * @return Returns the name.
 */
public String getName() {
return name;
}
/**
 * @param name The name to set.
 */
public void setName(String name) {
this.name = name;
}
}
 

and tables looks like this:


table class have: classId, name and clasroomId

and table classroom: classroomId and name

And i wonder how to make mapping for Set classes in Classroom.hbm.xml
and mapping for classroom in Class.hbm.xml

Thanks a lot.

[Slavko Glisic]

I try like this in Classroom.hbm.xml:

<set name="classes" cascade="all" inverse="true" lazy="false">
<key column="classroomId"/>
<one-to-many          class="net.sf.hibernatesample.ormapping.Class_"/>
</set>

and in Class_.hbm.xml:

<many-to-one name="classroom" class="net.sf.hibernatesample.ormapping.Classroom" column="classroomId"/>

But it seems like dont work because if I delete one class from the Classroom it doesnt update it...

[Slavko Glisic]

And I have this error:

Hibernate: update class_ set clssroomId=null where clssroomId=?
Hibernate: update class_ set clssroomId=null where clssroomId=?
ERROR [main] (JDBCExceptionReporter.java:72) - null,  message from server: "Column set to default value; NULL supplied to NOT NULL column 'clssroomId' at row 1"
 

Anybody had same problem?

b.t.w I use MySql