Hive : Insert overwrite multiple partitions

Hive supports dynamic partitioning, so you can build a query where the partition is just one of the source fields.

INSERT OVERWRITE TABLE dst partition (dt) 
SELECT col0, col1, ... coln, dt from src where ...

The where clause can specify which values of dt you want to overwrite.

Just include the partition field (dt in this case) last in the list from the source, you can even do SELECT *, dt if the dt field is already part of the source or even SELECT *,my_udf(dt) as dt, etc

By default, Hive wants at least one of the partitions specified to be static, but you can allow it to be nonstrict; so for the above query, you can set the following before the running:

set hive.exec.dynamic.partition.mode=nonstrict;