单项选择题
A.断言B.自主存取权限控制C.用户标识与密码D.强制存取权限控制
A.CREATE ASSERTIONB.CREATE TRIGGERC.CREATE ROLED.CREATE DOMAIN
A.CASCADEB.RESTRICTC.SET NULLD.SET DEFAULT
A.SQLCODEB.主语言变量C.游标D.数组
A.CREATE DATABASEB.CREATE TABLEC.CREATE VIEWD.CREATE INDEX
A.MAX()B.MIN()C.SUM()D.COUNT()
A.SELECT子句B.FROM子句C.WHERE子句D.ORDER BY子句
A.UNIQUEB.UNCLUSTERC.CLUSTERD.INDEX
A.UNIQUEB.NOT NULLC.PRIMARY KEYD.FOREIGN KEY
A.ALTER DATABASEB.ALTER TABLEC.DROP TABLED.DROP INDEX
A.主码必须唯一B.构成主码的属性不能取空值C.外码不能取空D.外码可以取空值