ID mapping


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

  1. In the Persistence Outline view, select the field to map. The Persistence Properties view (for attributes) displays the properties for the selected.

  2. In the Map As field, select ID.

  3. Use this table to complete the remaining fields on General tab in the Persistence Properties 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 (and its table) mapped to the entity attribute. See "Column" for details.
    • Name – Name of the database column.

    • Table – Name of the database table.

    • Insertable – Specify if the column is always included in SQL INSERT statements.

    • Updatable – Specify if the column is always included in SQL UPDATE statements.

    By default, the Column is assumed to be named identically to the attribute and always included in the INSERT and UPDATE statements.
    Temporal Specifies the type of data. See "Temporal" for details.
    • Date

    • Time

    • Timestamp



  4. Use this table to complete the fields on PK Generation tab in the Persistence Properties 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 on the PK Generation tab, depending on the selected Strategy. See "Persistence Properties 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(TemporalType.<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

Persistence Outline view
Persistence Properties view (for attributes)

 

Related concept

Understanding OR mappings
Understanding JSR220: EJB 3.0