我有一张table
TABLE PARTECIPATION
(PARTY_ID INT,
GUEST ...
PRIMARY KEY(PARTY_ID, GUEST)
FOREIGN KEY(PARTY_ID) REFERENCES PARTY(ID)
FOREIGN KEY(GUEST) REFERENCES GUEST(GUEST)
)还有一桌客人
TABLE GUEST
(NAME VARCHAR(20),
SURNAME VARCHAR(20),
AGE INT,
PRIMARY KEY(NAME, SURNAME)
)现在，如何将partecipation的guest元素设置为guest表的外键引用？
我应该在guest named，idk，id中创建一个列并将其设置为主键吗？或者我可以这样做：
TABLE PARTECIPATION
(PARTY_ID INT,
GUEST_NAME VARCHAR(20),
GUEST_SURNAME VARCHAR(20)
PRIMARY KEY(PARTY_ID, GUEST_NAME, GUEST_SURNAME)
FOREIGN KEY(PARTY_ID) REFERENCES PARTY(ID),
FOREIGN KEY(GUEST_NAME) REFERENCES GUEST(NAME),
FOREIGN KEY(GUEST_SURNAME) REFERENCES GUEST(SURNAME))
1条答案
按热度按时间vdzxcuhz1#
外键必须具有与其引用的主键相同的列数和顺序。这意味着您必须将多列放入一个外键定义中，如果pk有多列。