JPA Annotation

DiscriminatorColumn

Target: TYPE
Implemented Interfaces:
Annotation
Specifies the discriminator column for the SINGLE_TABLE and JOINED plain.

The mapping strategy and discriminator column are only specified for the root of an entity class hierarchy or subhierarchy in which a different inheritance strategy is applied.

If the DiscriminatorColumn annotation is missing, and a discriminator column is required, the name of the discriminator column defaults to "DTYPE" and the discriminator type to DiscriminatorType.STRING.

Example:

 {@snippet :
See Also:
DiscriminatorValue
DiscriminatorType
Since:
JPA 1.0

Public Annotation Attributes

String columnDefinition default ""
(Optional) The SQL fragment that is used when generating the DDL for the discriminator column.

Defaults to the provider-generated SQL to create a column of the specified discriminator type.

Since:
JPA 1.0
DiscriminatorType discriminatorType default STRING
(Optional) The type of object/column to use as a class discriminator.
Defaults to DiscriminatorType.STRING.
Since:
JPA 1.0
int length default 31
(Optional) The column length for String-based discriminator types.
Ignored for other discriminator types.
Since:
JPA 1.0
String name default "DTYPE"
(Optional) The name of column to be used for the discriminator.
Since:
JPA 1.0
String options default ""
(Optional) A SQL fragment appended to the generated DDL which declares this column.
May not be used in conjunction with DiscriminatorColumn.columnDefinition.
Since:
JPA 3.2