javax.persistence

## Annotation Type UniqueConstraint

    @Target(value={})
     @Retention(value=RUNTIME)
    public @interface UniqueConstraint

Specifies that a unique constraint is to be included in the generated DDL for a primary or secondary table.

        Example:
        @Entity
        @Table(
            name="EMPLOYEE",
            uniqueConstraints=
                @UniqueConstraint(columnNames={"EMP_ID", "EMP_NAME"})
        )
        public class Employee { ... }

Since:
  Java Persistence 1.0

### Required Element Summary

Required Elements
`String[]` `columnNames` (Required) An array of the column names that make up the constraint.

### Optional Element Summary

Optional Elements
`String` `name` (Optional) Constraint name.

### Element Detail

#### columnNames

    public abstract String[] columnNames

(Required) An array of the column names that make up the constraint.

#### name

    public abstract String name

(Optional) Constraint name. A provider-chosen name will be chosen if a name is not specified.

Since:
  Java Persistence 2.0

Default:
  ""