在SELECT语句中使用GROUP BY NO时,NO必须( )
A. 在WHERE子句中出现
B. 在HAVING子句中出现
C. 在SELECT子句中出现
D. 都不对
将student表按照gender列值进行分组查询,并计算出每个分组中各有多少名学生,正确SQL语句是( )。
A. SELECT TOTAL(*),gender FROM student GROUP BY gender
B. SELECT COUNT(*),gender FROM student GROUP BY gender
C. SELECT TOTAL(*),gender FROM student ORDER BY gender
D. SELECT COUNT(*),gender FROM student ORDER BY gender
从Student中查询出各专业学生的入学录取平均分,显示“专业”和“平均分”两列,保留一位小数。SELECT Specialty AS ① ,平均分=str( ② (AScores),5,1)FROM StudentGROUP BY ③
从Student中查询出各专业的学生总数,结果显示“专业”和“人数”两列。SELECT 专业=Specialty,人数= ①FROM Student② BY Specialty