SQL Alter: add multiple FKs?

Question

From here

ALTER TABLE ORDERS
ADD FOREIGN KEY (customer_sid) REFERENCES CUSTOMER(SID); 

How do i add several keys with SQL Server? is it something like the below? (I cant test ATM and unfortunately i have no way to test queries unless i run it through code)

ALTER TABLE ORDERS
ADD FOREIGN KEY (customer_sid) REFERENCES CUSTOMER(SID), 
ADD FOREIGN KEY (customer_sid2) REFERENCES CUSTOMER(SID2);

or is it like

ALTER TABLE ORDERS
ADD FOREIGN KEY (customer_sid, customer_sid2) REFERENCES CUSTOMER(SID, SID2)

Answer 1

The second block:

ALTER TABLE ORDERS ADD FOREIGN KEY (customer_sid) REFERENCES CUSTOMER(SID),
ADD FOREIGN KEY (customer_sid2) REFERENCES CUSTOMER(SID2);

will take care of what you are trying to do.

Answer 2

Here is the sql generated by sqlserver after I use the database diagram to draw the foreign key. Their approach is that one alter table for one foreign key

USE [TimeSheet]
GO
/****** Object:  Table [dbo].[WeekTasks]    Script Date: 05/19/2010 20:09:53 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[WeekTasks](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [WeekID] [int] NOT NULL,
    [TaskDescription] [nvarchar](100) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
    [ProjectID] [int] NOT NULL
 CONSTRAINT [PK_WeekTasks] PRIMARY KEY CLUSTERED 
(
    [ID] ASC
)WITH (PAD_INDEX  = OFF, IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]

GO
ALTER TABLE [dbo].[WeekTasks]  WITH CHECK ADD  CONSTRAINT [FK_WeekTasks_Projects] FOREIGN KEY([ProjectID])
REFERENCES [dbo].[Projects] ([ID])
ON DELETE CASCADE
GO
ALTER TABLE [dbo].[WeekTasks] CHECK CONSTRAINT [FK_WeekTasks_Projects]
GO
ALTER TABLE [dbo].[WeekTasks]  WITH CHECK ADD  CONSTRAINT [FK_WeekTasks_WeekTimeSheet] FOREIGN KEY([WeekID])
REFERENCES [dbo].[WeekTimeSheet] ([ID])
ON DELETE CASCADE
GO
ALTER TABLE [dbo].[WeekTasks] CHECK CONSTRAINT [FK_WeekTasks_WeekTimeSheet]