What Is Right Way To Generate Create Table

Hello everybody
I am doing update on Database using Erwin
Is any diffrence in this code and what is is right way to create table in my case ?
-- --- this code generated by Erwin 3.5.2
CREATE TABLE obooGrpAllotRmBooking (
BookingDate ASmallDateTime NOT NULL,
ID_RoomType ID NOT NULL,
ID_GrpAllot ID NOT NULL,
ContractQty hAvailQty DEFAULT 0
)
go


ALTER TABLE obooGrpAllotRmBooking
ADD PRIMARY KEY (ID_GrpAllot, ID_RoomType, BookingDate)
go




------------- This code generated by SQl server 7 generate script ---
CREATE TABLE [dbo].[obooGrpAllotRmBooking] (
[ID_GrpAllot] [ID] NOT NULL ,
[ID_RoomType] [ID] NOT NULL ,
[BookingDate] [ASmallDateTime] NOT NULL ,
[ContractQty] [hAvailQty] NULL
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[obooGrpAllotRmBooking] WITH NOCHECK ADD
PRIMARY KEY CLUSTERED
(
[ID_GrpAllot],
[ID_RoomType],
[BookingDate],
[ContractQty]

) ON [PRIMARY]
GO

ALTER TABLE [dbo].[obooGrpAllotRmBooking] WITH NOCHECK ADD
CONSTRAINT [DF__obooGrpAl__Contr__78DED853_05] DEFAULT (0) FOR [ContractQty]
GO

Thanks