Difference between revisions of "EclipseLink/UserGuide/JPA/Basic JPA Development/Mapping/Basic Mappings/Transient"

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By default, EclipseLink persistence provider assumes that all the fields of an entity are persistent.
 
By default, EclipseLink persistence provider assumes that all the fields of an entity are persistent.
  
Use the <tt>@Transient</tt> annotation or <code><transient</code> XML to specify a field or property of an entity that is not persistent (for example, a field or property that is used at run time, but that is not part of the entity's state).
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Use the <tt>@Transient</tt> annotation or <code><nowiki><transient></nowiki></code> XML to specify a field or property of an entity that is not persistent (for example, a field or property that is used at run time, but that is not part of the entity's state).
  
 
EclipseLink persistence provider will not persist (or create database schema) for a property or field annotated with <tt>@Transient</tt>.
 
EclipseLink persistence provider will not persist (or create database schema) for a property or field annotated with <tt>@Transient</tt>.
  
This annotation can be used with <tt>@Entity</tt>, [[#@MappedSuperclass|<tt>@MappedSuperclass</tt>]], and [[#@Embeddable|<tt>@Embeddable</tt>]].
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This annotation can be used with <tt>@Entity</tt>, <tt>@MappedSuperclass</tt>, and <tt>@Embeddable</tt>.
 
{{EclipseLink_Spec
 
{{EclipseLink_Spec
 
|section=Section 8.1 "Entity"}}
 
|section=Section 8.1 "Entity"}}
  
 
The <tt>@Transient</tt> annotation does not have attributes.
 
The <tt>@Transient</tt> annotation does not have attributes.
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 +
If a field is marked as Java <code>transient</code> it will also be ignored.
  
 
The following example shows how to use the <tt>@Transient</tt> annotation to specify <tt>Employee</tt> field <tt>currentSession</tt> as not persistent. EclipseLink persistence provider will not persist this field.
 
The following example shows how to use the <tt>@Transient</tt> annotation to specify <tt>Employee</tt> field <tt>currentSession</tt> as not persistent. EclipseLink persistence provider will not persist this field.

Revision as of 14:53, 27 October 2011

EclipseLink JPA

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@Transient

By default, EclipseLink persistence provider assumes that all the fields of an entity are persistent.

Use the @Transient annotation or <transient> XML to specify a field or property of an entity that is not persistent (for example, a field or property that is used at run time, but that is not part of the entity's state).

EclipseLink persistence provider will not persist (or create database schema) for a property or field annotated with @Transient.

This annotation can be used with @Entity, @MappedSuperclass, and @Embeddable.

Elug javaspec icon.gif

For more information, see Section 8.1 "Entity" in the JPA Specification.

The @Transient annotation does not have attributes.

If a field is marked as Java transient it will also be ignored.

The following example shows how to use the @Transient annotation to specify Employee field currentSession as not persistent. EclipseLink persistence provider will not persist this field.

Example: @Transient Annotation
@Entity
public class Employee implements Serializable {
    ...
    @Id
    int id;
 
    @Transient
    Session currentSession;
    ...
}
Elug javaspec icon.gif

For more information, see Section 11.1.48 "Transient Annotation" in the JPA Specification.


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