Question

例如，对于给定的表格。

i  |  j   | v  |
---|------|----|
1  |  2   | 2  |
1  |  2   | 3  |
1  |  2   | 4  |
1  |  4   | 1  |
1  |  4   | 6  |
1  |  4   | 8  |

Answer 1

从我假设对于FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.mr.MapredLocalTask和i列中的每个重复值集合的问题，您试图从j或minimum值中检索{ {1}}。

获取maximum行：

<强>结果：

max

要获取v的SELECT t1.i ,t1.j ,max(t1.v) AS v FROM table1 t1 GROUP BY t1.i ,t1.j ORDER BY t1.i ,t1.j值行，请在上述查询中将i | j | v --------- 1 2 4 1 4 8替换为min。

<强> DEMO

Answer 2

尝试使用以下短代码：

select i, j, MAX(v) v from #temp group by i, j

<强>结果：

i | j | v
---------
1   2   4
1   4   8

Answer 3

create table #temp (i int, j int , k int)

insert into #temp values(1,2,2)
insert into #temp values(1,2,3)
insert into #temp values(1,2,4)
insert into #temp values(1,4,1)
insert into #temp values(1,4,6)
insert into #temp values(1,4,8)

SELECT * from #temp;

WITH CTE  as
(select *, ROW_NUMBER () over (partition by j order by k)  rowno from #temp )
select i,j,k from cte where rowno = 1

如何使用sql查找每组重复行的顶行？

3 个答案: