I have class like Clazz

```
    @Table(
    name="tablename", 
    uniqueConstraints=
        @UniqueConstraint(
                          name= "uniqueColumn_deleted_uk",
                          columnNames={"myuniquecolumn", "deleted"}
                         )

    )
 public class Clazz {

     @Column(name = "deleted")
     private LocalDateTime deleted;
}

```

deleted is nullable, PosgreSQL creates unique index like 

```
CREATE UNIQUE INDEX uniqueColumn_date_uk ON public.tablename (short_code_3, deleted);

```

and it allows insert duplicate myuniquecolumn when deleted is NULL.

How prevent this?

I want have non duplicates when deleted is null.