单项选择题
A.3 B.4 C.5 D.6
A.DROP salary VIEW B.DROP VIEW salary C.DELETE salary VIEW D.DELETE salary
A.CREATE VIEW salary AS系号,AVG(工资)AS平均工资FROM教师; GROUP 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FROM教师; GROUP BY系号 D.CREATE VIEW salary AS SELECT系号,AVG(工资)AS平均工资FROM教师; GROUP BY系号