Annotation Interface ManyToOne
OneToMany
entity side must used the
mappedBy
element to specify the relationship field or
property of the entity that is the owner of the relationship.
The ManyToOne
annotation may be used within an
embeddable class to specify a relationship from the embeddable
class to an entity class. If the relationship is bidirectional, the
non-owning OneToMany
entity side must use the mappedBy
element of the OneToMany
annotation to specify the
relationship field or property of the embeddable field or property
on the owning side of the relationship. The dot (".") notation
syntax must be used in the mappedBy
element to indicate the
relationship attribute within the embedded attribute. The value of
each identifier used with the dot notation is the name of the
respective embedded field or property.
Example 1: @ManyToOne(optional=false) @JoinColumn(name="CUST_ID", nullable=false, updatable=false) public Customer getCustomer() { return customer; } Example 2: @Entity public class Employee { @Id int id; @Embedded JobInfo jobInfo; ... } @Embeddable public class JobInfo { String jobDescription; @ManyToOne ProgramManager pm; // Bidirectional } @Entity public class ProgramManager { @Id int id; @OneToMany(mappedBy="jobInfo.pm") Collection<Employee> manages; }
- Since:
- 1.0
-
Optional Element Summary
Modifier and TypeOptional ElementDescription(Optional) The operations that must be cascaded to the target of the association.(Optional) Whether the association should be lazily loaded or must be eagerly fetched.boolean
(Optional) Whether the association is optional.(Optional) The entity class that is the target of the association.
-
Element Details
-
targetEntity
Class targetEntity(Optional) The entity class that is the target of the association.Defaults to the type of the field or property that stores the association.
- Default:
- void.class
-
cascade
CascadeType[] cascade(Optional) The operations that must be cascaded to the target of the association.By default no operations are cascaded.
- Default:
- {}
-
fetch
FetchType fetch(Optional) Whether the association should be lazily loaded or must be eagerly fetched. The EAGER strategy is a requirement on the persistence provider runtime that the associated entity must be eagerly fetched. The LAZY strategy is a hint to the persistence provider runtime.- Default:
- EAGER
-
optional
boolean optional(Optional) Whether the association is optional. If set to false then a non-null relationship must always exist.- Default:
- true
-