摘要： 关系表的级联更新： on update cascadeon delete cascade 是级联删除的意思意思是 当你更新或删除主键表时，那么外键表也会跟随一起更新或删除CREATE TABLE Countries(CountryId INT PRIMARY KEY) INSERT INTO Countries (CountryId) VALUES (1) INSERT INTO Countries (CountryId) VALUES (2) INSERT INTO Countries (CountryId) VALUES (3) GO CREATE TABLE Cities( CityId 阅读全文