将student表中class字段删除的命令是（）。
A: DROPTABLEstudentclass
B: ALTER TABLE student class
C: ALTER TABLE student DROP class
D: DROP TABLE student ALTER class
A: DROPTABLEstudentclass
B: ALTER TABLE student class
C: ALTER TABLE student DROP class
D: DROP TABLE student ALTER class
举一反三
- 以下可以用来修改表结构的命令是（）。 A: alter table student add sphone int B: alter table student add unique(sfzh) C: alter table student drop column saddress D: alter table student alter column sage int
- 以下可以用来修改表结构的命令是（）。 A: alter table student add sphone int（11） B: alter table student unique(sfzh) C: alter table drop column saddress D: alter table student change age sage int(2)
- 删除STUDENT表中C2的默认值约束语句是（）。 A: ALTER TABLE STUDENT DROP CONSTRAINT C2 B: DROP CONSTRAINT C2 C: DELETE CONSTRAINT C2 D: DROP STUDENT
- 删除数据表student的命令是________。 A: drop table student; B: drop student; C: delete table student; D: drop student;
- 以下是修改视图的语句是 A: create or replace view st1 as select* from student; B: alter view st1 as select name from student join class on student.cid=class.id; C: alter table st1 modify class int(3); D: create or replace table st1 as select* from student;