Somehow I cannot use Set instead of TreeSet. The code works well if I replace in all methods Set with TreeSet. In the documentation however it's recommended to use interfaces like Set, List or Collection and not implementations. Someone any idea what wrong?




Hibernate version: 3.2.1GA

Mapping documents: Only Annotated

Full stack trace of any exception that occurs:
<code>
Exception in thread "main" org.hibernate.MappingException: Could not determine type for: java.util.Set, for columns: [org.hibernate.mapping.Column(twos)]
at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:266)
at org.hibernate.mapping.Column.getSqlTypeCode(Column.java:138)
at org.hibernate.mapping.Column.getSqlType(Column.java:182)
at org.hibernate.mapping.Table.sqlCreateString(Table.java:394)
at org.hibernate.cfg.Configuration.generateSchemaCreationScript(Configuration.java:848)
at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:94)
at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:61)
at Main.main(Main.java:84)
</code>


Name and version of the database you are using:MySQL 5
The generated SQL (show_sql=true): None


<code>
import java.util.*;
import javax.persistence.*;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;

public class Main {

@Entity
@Table(name="manyparttwo")
public static class ManyPartTwo {

@Id
@GeneratedValue
private Integer id;

private Set<ManyPartOne> ones = new TreeSet<ManyPartOne>();

@ManyToMany(
targetEntity=ManyPartOne.class,
cascade=CascadeType.PERSIST,
mappedBy="twos"
)
public Set<ManyPartOne> getOnes() {
return ones;
}

public void setOnes(Set<ManyPartOne> ones) {
this.ones = ones;
}

public Integer getId() {
return id;
}

public void setId(Integer id) {
this.id = id;
}

}

@Entity
@Table(name="manypartone")
public static class ManyPartOne {

@Id
@GeneratedValue
private Integer id;

private Set<ManyPartTwo> twos = new TreeSet<ManyPartTwo>();

@ManyToMany(

targetEntity=ManyPartTwo.class,
cascade=CascadeType.PERSIST
)
@JoinTable(
name="many2many",
joinColumns={@JoinColumn(name="one", referencedColumnName="id")},
inverseJoinColumns={@JoinColumn(name="two", referencedColumnName="id")}
)
public Set<ManyPartTwo> getTwos() {
return twos;
}

public void setTwos(Set<ManyPartTwo> twos) {
this.twos = twos;
}

public Integer getId() {
return id;
}

public void setId(Integer id) {
this.id = id;
}
}

public static void main(String[] args) {
AnnotationConfiguration cfg = new AnnotationConfiguration();
cfg.addAnnotatedClass(Main.ManyPartOne.class);
cfg.addAnnotatedClass(Main.ManyPartTwo.class);
cfg.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQLDialect");

new SchemaExport(cfg).create(true, false);

}

}
</code>

Hi Mike,

You cannot mix where the annotations are. You must annotate either everything at the getter level or everything at variable declartion level.

Cheers,

Andy

Thank you very much, that solved this problem and my problem with the association table. Somehow I was thinking that ManyToMany has to be defined at getter method level. Anyway that's great :-)

Mike

Mike, can you post the final version of your code? I'm not quite understanding the solution. I'm having the same problem.