SQL中删除表XS.DBF的命令是_____XS.
举一反三
- 要从 xs 表中删除字段 BJ 的命令是 Alter Table xs Drop ________ 。
- 删除表XS的命令是DROPTABLE
- 设数据表XS.DBF中有学号(C)字段,逻辑删除学号中以“2015”开头的记录,正确的SQL语句是________. A: DELETE FROM XS WHERE “2015”$学号 B: DELETE FROM XS WHERE LEFT(学号，4)==”2015” C: DELETE FROM XS FOR “2015”$学号 D: DELETE FROM XS FOR LEFT(学号，4)==”2015”
- 删除xs表
- 创建xs1表,xs1表中所有学生学号都必须是出现在xs表中的学号,且当删除、修改或更新xs表中的学号且该学号存在于xs1表中时,拒绝对xs表的删除或更新操作。(xs1表只定义xs表中的前三列即可)