建立一个视图salary,该视图包括了系号和(该系的)平均工资两个字段,正确的SQL语句是A.CREATE VIEW
建立一个视图salary,该视图包括了系号和(该系的)平均工资两个字段,正确的SQL语句是
A.CREATE VIEW salary AS 系号,AVG(工资)AS 平均工资 FROM 教师; GROUPBY 系号
B.CREATE VIEW salary AS SELECT系号,AVG(工资)AS 平均工资 FROM 教师; GROUPBY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