ID mapping

Use an ID Mapping to specify the primary key of an entity. ID mappings may be used with a Entity or Mapped superclass. Each Entity must have an ID mapping.

  1. In the JPA Structure view, select the field to map. The JPA Details view (for attributes) displays the properties for the selected.

  2. In the Map As field, select ID.

  3. Use this table to complete the General information fields in the JPA Details view.

    Property Description Default
    Map As Defines this mapping as an ID Mapping.

    This field corresponds to the @Id annotation.

    		 ID
    Column The database column mapped to the entity attribute. See "Column" for details. By default, the Column is assumed to be named identically to the attribute.
    Table The database table mapped to the entity attribute. By default, the Table is assumed to be identical to the table associated with the entity.
    Temporal Specifies the type of data. See "Temporal" for details.

    • Date

    • Time

    • Timestamp

  4. Use this table to complete the fields in Primary Key Generation information area in the JPA Details view.

    Property Description Default
    Primary Key Generation These fields define how the primary key is generated.
      Strategy See "Primary Key Generation" for details.

    • Auto

    • Sequence

    • Identity

    • Table

    		 Auto
      Generator Name Name of the primary key generator specified in the Strategy

Additional fields will appear in the Primary Key Generation information area, depending on the selected Strategy. See "JPA Details view (for attributes)" for additional information.

Eclipse adds the following annotations to the field:

@Id
@Column(name="<COLUMN_NAME>", table="<TABLE_NAME>", insertable=<INSERTABLE>,
    updatable=<UPDATABLE>)
@Temporal(<TEMPORAL>)
@GeneratedValue(strategy=GeneratorType.<STRATEGY>, generator="<GENERATOR_NAME>")@TableGenerator(name="<TABLE_GENERATOR_NAME>", table = "<TABLE_GENERATOR_TABLE>", 
    pkColumnName = "<TABLE_GENERATOR_PK>", 
    valueColumnName = "<TABLE_GENERATOR_VALUE_COLUMN>", 
    pkColumnValue = "<TABLE_GENERATOR_PK_COLUMN_VALUE>")@SequenceGenerator(name="<SEQUENCE_GENERATOR_NAME>", 
    sequenceName="<SEQUENCE_GENERATOR_SEQUENCE>")

 

Related task

Mapping an entity

 

Related reference

JPA Structure view
JPA Details view (for attributes)

 

Related concept

Understanding OR mappings
Understanding EJB 3.0 Java Persistence API