javax.jdo.annotations

Annotation Type Unique

@Target(value={TYPE,FIELD,METHOD})
 @Retention(value=RUNTIME)
 @Repeatable(value=Uniques.class)
public @interface Unique

Annotation for a database unique constraint. Used for database schema generation to create unique constraints. Also used to reorder database operations when flushing changes to avoid unique constraint violations. Corresponds to the xml element "unique".

Since:

2.1

Version:

3.2

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
Column[]	columns Columns that compose this unique constraint.
String	deferred Whether this unique constraint is deferred until commit.
Extension[]	extensions Vendor extensions.
String[]	members Member (field and property) names that compose this unique constraint.
String	name Name of the unique constraint.
String	table Table for the unique constraint.

Element Detail

name

public abstract String name

Name of the unique constraint.

Returns:

the name of the unique constraint

Default:

""

table

public abstract String table

Table for the unique constraint. This is needed iff annotating a type where this unique constraint is not for the primary table for the persistent class or interface.

Returns:

the table on which the unique constraint is defined

Default:

""

deferred

public abstract String deferred

Whether this unique constraint is deferred until commit.

Returns:

whether this unique constraint is deferred until commit

Default:

""

members

public abstract String[] members

Member (field and property) names that compose this unique constraint.

Returns:

member names that compose this unique constraint

Default:

{}

columns

public abstract Column[] columns

Columns that compose this unique constraint.

Returns:

columns that compose this unique constraint

Default:

{}

extensions

public abstract Extension[] extensions

Vendor extensions.

Returns:

the vendor extensions

Default:

{}