工作(身份、职级)
数据:
work
------------------
1 | A
1 | B
1 | C
1 | D
2 | A
2 | C
2 | B
3 | C我需要找到所有的in与他们的计数有共同的秩,它应该显示只有当秩的计数大于2,并打印它们的降序。我已经为此编写了一个mysql查询,但是,我对SparkSQL和HIVEQL还是新手。所以请帮帮我怎么做。例如,使用上述结果集的数据应该是:
mysql查询是:
select a.id,b.id
from work as a, work as b
where a.id>b.id
group by a.id,b.id having group_concat(distinct a.rank order by a.rank)=group_concat(distinct b.rank order by b.rank)
---------------------
id1 | id2 | Count
---------------------
A | B | 3
B | C | 3发布于 2016-11-05 23:45:49
我不认为Hive支持group_concat()。我想这也是一样的:
select a.id, b.id, a.cnt
from (select a.*, count(*) over (partition by a.id) as cnt
from work a
) a join
(select b.*, count(*) over (partition by b.id) as cnt
from work b
) b
on a.rank = b.rank and a.cnt = b.cnt
where a.id < b.id -- I *think* this is allowed in Hive; it not, a subquery or expression in the `having` clause will do the same thing
group by a.id, b.id, a.cnt
having count(*) = a.cnt;这是获得具有相同排名的ids对的更自然的方法。事实上,在几乎任何数据库中,它都应该比MySQL版本更高效。cross join生成大量数据。
https://stackoverflow.com/questions/40444326
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