CREATE TABLE Transformator (
       idTransformator      int IDENTITY,
       dispName             varchar( 20 ) NOT NULL,
       idTrType             int NOT NULL
)
go

ALTER TABLE Transformator
       ADD PRIMARY KEY NONCLUSTERED (idTransformator)
go

CREATE TABLE TrType (
       idTrType             int IDENTITY,
       trType               varchar( 20 ) NOT NULL
)
go

ALTER TABLE TrType
       ADD PRIMARY KEY NONCLUSTERED (idTrType)
go

ALTER TABLE Transformator
       ADD FOREIGN KEY (idTrType)
                             REFERENCES TrType
go

create trigger tI_Transformator on Transformator for INSERT as
/* ERwin Builtin Thu Jul 14 14:09:07 2005 */
/* INSERT trigger on Transformator */
begin
  declare  @numrows int,
           @nullcnt int,
           @validcnt int,
           @errno   int,
           @errmsg  varchar( 255 )

  select @numrows = @@rowcount
  /* ERwin Builtin Thu Jul 14 14:09:07 2005 */
  /* TrType R/2 Transformator ON CHILD INSERT SET NULL */
  if
    /* update(idTrType) */
    update(idTrType)
  begin
    update Transformator
      set
        /* Transformator.idTrType = NULL */
        Transformator.idTrType = NULL
      from Transformator,inserted
      where
        /*  */
     and
        not exists (
          select * from TrType
          where
            /* inserted.idTrType = TrType.idTrType */
            inserted.idTrType = TrType.idTrType
        )
  end


  /* ERwin Builtin Thu Jul 14 14:09:07 2005 */
  return
error:
    raiserror @errno @errmsg
    rollback transaction
end
go