SQL Alter:添加多个FK？

Question

从这里

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

如何使用SQL Server添加多个密钥？它是下面的东西吗？(我不能测试ATM,不幸的是我无法测试查询,除非我通过代码运行它)

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

还是喜欢

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

Answer 1

ALTER TABLE ORDERS
    ADD FOREIGN KEY (customer_sid) REFERENCES CUSTOMER(SID),
        FOREIGN KEY (customer_sid2) REFERENCES CUSTOMER(SID2),
        FOREIGN KEY (customer_sid3) REFERENCES CUSTOMER(SID3);

Answer 2

你问题的第二个代码块:

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

会照顾你想要做的事情.