主鍵(標識列):
ID INT NOT NULL IDENTITY(1,1) PRIMARY KEY
唯一約束:
UserName VARCHAR(50) NOT NULL UNIQUE
默認約束:
UserPass VARCHAR(20) NOT NULL DEFAULT('123456')
檢查約束:
Age INT NOT NULL CHECK(Age>18)
主外鍵約束:(外鍵表中建立約束)
UserID INT NOT NULL REFERENCES UserInfo(ID)
級聯刪除:
UserID INT NOT NULL REFERENCES UserInfo(ID) ON DELETE CASCADE
級聯更新:
UserID INT NOT NULL REFERENCES UserInfo(ID) ON UPDATE CASCADE
級聯更新、刪除
UserID INT NOT NULL REFERENCES UserInfo(ID) ON DELETE CASCADE ON UPDATE CASCADE
其中,UserInfo爲主鍵表表名