给出表R1的结果是什么？

Question

A   B   C
3   1   0
5   2   3
5   4   2
2   6   3

给出表R1的结果是什么？

Select R1.A , count(*) 
from R1 (select A from R1 GROUP BY A ) R2
where R1.A >= R2.A 
group by R1.A 
HAVING COUNT (*) > 1; 

Answer 1

我想您的查询在第一个R1之后缺少逗号。如果添加了该内容，则结果可能如下所示-

Select R1.A , count(*) 
from R1, (select A from R1 GROUP BY A ) R2
where R1.A >= R2.A 
group by R1.A 
HAVING COUNT (*) > 1; 

结果-

A  |  count(*)
--------------
3  |  2
5  |  2