Have 2 entities:
Module entity with list of properties
@Entity
@Table(name = "module")
public class ModuleEntity {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Integer id;
@OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, orphanRemoval = true)
@JoinColumn(name = "module_id", nullable = false)
private List<PropertyEntity> properties;
//getters/setters etc
}
Property entity with composite ID
@Entity
@IdClass(PropertyEntityId.class)
@Table(name = "module_property")
public class PropertyEntity {
@Id
@Column(name = "module_id")
private Integer moduleId;
@Id
@Column(name = "[key]")
private String key;
@Column(name = "value")
private String value;
//getters/setters etc
}
With corresponding ID
public class PropertyEntityId implements Serializable {
private Integer moduleId;
private String key;
//getters/setters etc
}
Problem is that when I'm trying to insert Module with Properties list JPA tries to insert module_id twice and second value is null in this case
GenericJDBCException: could not execute statement [The value is not set for the parameter number 4.] [insert into module_property (module_id,value,[key],module_id) values (?,?,?,?)]
What's wrong in my mapping?
You need to replace the moduleId property in the PropertyEntity and PropertyEntityId with the module property:
@Id
@ManyToOne
@JsonBackReference
@JoinColumn(name = "module_id")
private ModuleEntity module;
And you should fix the properties field in the ModuleEntity entity:
@JsonManagedReference
@OneToMany(mappedBy = "module", fetch = FetchType.EAGER, cascade = CascadeType.ALL, orphanRemoval = true)
private List<PropertyEntity> properties;
See example 164 in Hibernate ORM User Guide.
You also need to set a reference to the ModuleEntity instance in each PropertyEntity object that belongs to it. You can do this manually, or use the @JsonManagedReference and @JsonBackReference annotations to have Jackson take care of this for you when deserializing the object.