Hive uses the left OUTER JOIN to implement the NOT in clause

The current hive does not support the syntax for a non in that contains a query clause, and the following HQ statement is not supported:

Query data in the key field in table A, but not in table B

Select A.key from a where key not in (select key from B) This statement is not supported in hive

Queries can be made through the left outer join (assuming that the B table contains another field Key1

Select A.key from a LEFT outer join B in A.key=b.key where b.key1 is null

Reprint http://chiyx.iteye.com/blog/1530981