Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
550 views
in Technique[技术] by (71.8m points)

hadoop - Hive doesn't support in, exists. How do I write the following query?

I have two tables A and B that both have a column id. I wish to obtain ids from A that are not present in B. The obvious way is:

SELECT id FROM A WHERE id NOT IN (SELECT id FROM B)

Unfortunately, Hive doesn't support in, exists or subqueries. Is there a way to achieve the above using joins?

I thought of the following

SELECT A.id FROM A,B WHERE A.id<>B.id

But it seems like this will return the entirety of A, since there always exists an id in B that is not equal to any id in A.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can do the same with a LEFT OUTER JOIN in Hive:

SELECT A.id
FROM A
LEFT OUTER JOIN B
ON (B.id = A.id)
WHERE B.id IS null

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...