CREATE VIEW语句用于在SQL中建立视图。如果要求对视图更新时，必须满足子查询中的条件表达式，应当在该语句中使用短语()。

A . CREATE vIEw salary AS系号．AVG(工资)AS平均工资FR()M教师GR()UP BY系号 B . CREATE VIEW salary AS SELECT 系号，AVG(工 资)AS平均工资FROM教师GROUP BY系名 C . CREATE VIEw salary SELECT 系号，AVG(工资)AS平均工资FR()M教师 GR()UP BY系号 D . CREATE VIEW salary AS SELECT系号，AVG(工 资)AS平均工资FR()M教师 GROUP BY系号

A . CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department _ id IN (10,20); B . CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) WITH READ ONLY; C . CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) WITH CHECK OPTION; D . CREATE FORCE VIEW emp_vu AS SELECT * FROM employees WITH department_id IN (10,20); E . CREATE FORCE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) NO UPDATE

A . CREATESCHEMA B . CREATETABLE C . CREATEVIEW D . CREATEINDEX

A . 外模式 B . 模式 C . 内模式 D . 都不对应

A . CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20); B . CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) WITH READ ONLY; C . CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) WITH CHECK OPTION; D . CREATE FORCE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20); E . CREATE FORCE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) NO UPDATE

A . UNIQE B . JOIN C . GROUP BY D . FROM

A . CREATE VIEW myview SELECT*FROM歌手WHERELIKE（“1”歌手号） B . CREATE VIEW myview ASSELECT*FROM歌手WHERELIKE（“1”歌手号） C . CREATE VIEW myview SELECT*FROM歌手WHERELEFT（歌手号，1）=“1” D . CREATE VIEW myview ASSELECT*FROM歌手WHERELEFT（歌手号，1）="1&quot

在SQL语句中，删除视图语句的是()。 A．ZAP VIEW B．ALDER VIEW C．DELETE VIEW D．DROP VIEW

在Visual FoxPro中，下列关于SQL表定义语句(CREATE TABLE)的说法错误的是（）。 A.可以定义一个新的基本表结构 B.可以定义数据库表中的主关键字 C.可以定义表的域完整性、字段有效性规则等 D.对自由表，同样可以实现其完整性、有效性规则等信息的设置

A．CREATESCHEMA B．CREATETABLE C．CREATEVIEW D．CREATEINDEX

A．数据定义语言 B．数据转换语言 C．数据操纵语言 D．数据控制语言

A．UPDATE view_stu SET chinese = 100; B．ALTER view_stu SET chinese = 100; C．UPDATE VIEW view_stu SET chinese = 100; D．ALTER VIEW view_stu SET chinese = 100;