下列哪个SQL语句可以用于从表users中删除数据:()。
找出正确的叙述()A DROP TABLE表示删除表的定义B DELETE FROM TABLE表示删除表的定义C DROP TABLE 等于DELETE FROM TABLED DROP TABLE属于数据操纵语言
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删除表S中字段C的SQL命令是( )。A.ALTER TABLE s DELETE cB.ALTER TABLE s DROP c.C.DELETE TABLE s DELETE cD.DELETE TABLE s DROP c
根据SQL标准,删除表student中对字段sno的唯一性约束,应该使用下面哪条语句? ()A drop sno from table studentB alter table student drop snoC alter table student drop unique(sno)D alter table student drop sno unique
根据SQL标准,要删除表student中所有数据,但不将表student的定义一起删除,下面哪个语句可以适用?()A delete from studentB delete all from studentC delete * from studentD drop table student
把表中“学历”字段的有效性规则取消,正确的SQL语句是( )。A.ALTER TABLE学生ALTER学历DROP CHECKB.ALTER TABLE学生DELETE学历DROP CHECKC.ALTER TABLE学生DELETE CHECK学历D.ALTER TABLE学生DROP CHECK学历
删除student表中“平均成绩”字段的正确SQL命令是( )。A. DELETE TABLE student DELETE COLUMN平均成绩B. ALTER TABLE student DELETE COLUMN平均成绩C. ALTER TABLE student DROP COLUMN平均成绩D. DELETE TABLE student DROP COLUMN平均成绩
从数据库中删除表的命令是______。A、DROP TABLE B、ALTER TABLE C、DELETE TABLE D、USE