下面哪一个RDD操作是求和?()
A.count
B.distinct
C.sum
D.avg
A.count
B.distinct
C.sum
D.avg
第5题
A.select student_id,student_name,sum(score) from student where score<60 order by score;
B.select distinct student_id,avg(score) from student where score<60 order by avg(score);
C.select student_id,student_name,avg(score) av from student where score<60 group by student_id order by av asc;
D.select student_id,student_name,avg(score) av from student group by student_id where score<60 order by av asc;
第6题
A.SELECT 性别,COUNT(*) AS 人数 FROM 职工WHERE 工资<800 ORDER BY 性别
B.SELECT 性别,COUNT(*) AS 人数 FROM 职工WHERE 工资<800 GROUP BY 性别
C.SELECT 性别,SUM(*) AS 人数 FROM 职工WHERE 工资<800 GROUP BY 性别
D.SELECT 性别,AVG(*) AS 人数 FROM 职工
第7题
A.GROUPBY出版单位HAVINGCOUNT总编号>=2
B.GROUPBY出版单位HAVINGCOUNT(DISTINCT总编号)>=2
C.GROUPBY出版单位>=2
D.WHERE总编号>=2
第9题
A.“=SUM(A2:A8)”
B.“=SUM(A2,A8)”
C.“=avg(A2:A8)”
D.“=avg(A2,A8)”