Package org.hibernate.annotations

Annotation Type Generated

  • @Target({FIELD,METHOD})@Retention(RUNTIME)public @interfaceGenerated
    Specifies that the value of the annotated property is generated by the database. The generated value will be automatically retrieved using a SQLselect after it is generated.

    @Generated relieves the program of the need to explicitly callrefresh() to synchronize state held in memory with state generated by the database when a SQLinsert orupdate is executed.

    This is most useful when:

    • a database table has a column value populated by a database trigger,
    • a mapped column has a default value defined in DDL, in which case@Generated is used in conjunction withColumnDefault,
    • aSQL expression is used to compute the value of a mapped column, or
    • when a custom SQLinsert orupdate statement specified by an entity assigns a value to the annotated property of the entity, ortransforms the value currently assigned to the annotated property.

    On the other hand:

    • for identity/autoincrement columns mapped to an identifier property, useGeneratedValue, and
    • for columns with agenerated always as clause, prefer theGeneratedColumn annotation, so that Hibernate automatically generates the correct DDL.
    See Also:
    GeneratedValue,ColumnDefault,GeneratedColumn

    • Optional Element Summary

      Optional Elements 
      Modifier and TypeOptional ElementDescription
      EventType[]event
      Specifies the events that cause the value to be generated by the database.
      Stringsql
      A SQL expression used to generate the value of the column mapped by the annotated property.
      GenerationTimevalue
      Deprecated.
      booleanwritable
      Determines if the value currently assigned to the annotated property is included in SQLinsert andupdate statements.

    • Element Detail

      • event

        EventType[] event
        Specifies the events that cause the value to be generated by the database.
        • IfEventType.INSERT is included, the generated value will be selected after each SQLinsert statement is executed.
        • IfEventType.UPDATE is included, the generated value will be selected after each SQLupdate statement is executed.
        Default:
        {org.hibernate.generator.EventType.INSERT}

      • value

        @Deprecated(since="6.2")GenerationTime value
        Deprecated.
        Specifies the events that cause the value to be generated by the database.
        • IfGenerationTime.INSERT, the generated value will be selected after each SQLinsert statement is executed.
        • IfGenerationTime.UPDATE, the generated value will be selected after each SQLupdate statement is executed.
        • IfGenerationTime.ALWAYS, the generated value will be selected after each SQLinsert orupdate statement is executed.
        Default:
        org.hibernate.annotations.GenerationTime.INSERT

      • sql

        String sql
        A SQL expression used to generate the value of the column mapped by the annotated property. The expression is included in generated SQLinsert andupdate statements.
        Default:
        ""

      • writable

        boolean writable
        Determines if the value currently assigned to the annotated property is included in SQLinsert andupdate statements. This is useful if the generated value is obtained by transforming the assigned property value as it is being written.

        Often used in combination withSQLInsert,SQLUpdate, orColumnTransformer.write().

        Returns:
        true if the current value should be included in SQLinsert andupdate statements.
        Default:
        false