Annotation Interface ForeignKey
The ConstraintMode
value is used to specify whether foreign
key constraints should be generated.
The syntax used in the foreignKeyDefinition
element
should follow the SQL syntax used by the target database for foreign
key constraints. For example, this may be similar the following:
FOREIGN KEY ( <COLUMN expression> {, <COLUMN expression>}... ) REFERENCES <TABLE identifier> [ (<COLUMN expression> {, <COLUMN expression>}... ) ] [ ON UPDATE <referential action> ] [ ON DELETE <referential action> ]When the
ConstraintMode
value is
CONSTRAINT
, but the foreignKeyDefinition
element is not specified, the provider will generate foreign key
constraints whose update and delete actions it determines most
appropriate for the join column(s) to which the foreign key
annotation is applied.-
Optional Element Summary
Modifier and TypeOptional ElementDescription(Optional) The foreign key constraint definition.(Optional) The name of the foreign key constraint.(Optional) Used to specify whether a foreign key constraint should be generated when schema generation is in effect.
-
Element Details
-
name
String name(Optional) The name of the foreign key constraint. If this is not specified, it defaults to a provider-generated name.- Default:
- ""
-
value
ConstraintMode value(Optional) Used to specify whether a foreign key constraint should be generated when schema generation is in effect.A value of
CONSTRAINT
will cause the persistence provider to generate a foreign key constraint. If theforeignKeyDefinition
element is not specified, the provider will generate a constraint whose update and delete actions it determines most appropriate for the join column(s) to which the foreign key annotation is applied.A value of
NO_CONSTRAINT
will result in no constraint being generated.A value of
PROVIDER_DEFAULT
will result in the provider's default behavior (which may or may not result in the generation of a constraint for the given join column(s).- Default:
- CONSTRAINT
-
foreignKeyDefinition
String foreignKeyDefinition(Optional) The foreign key constraint definition.- Default:
- ""
-