Hive SQL: how to insert only newer records into a table?

Question

I have 3 tables. I'm inserting data from t1 into t2 and t3. I would like to only insert the data from t1 that is newer than the newest data already in t2.

This is my current select statement:

from (select *, concat(column1, '|', column2) as id from t1 
  where column1 = "value1") t
insert into table t2
  select 
  column3,
  id
insert into t3
  select 
  column4
  id

t1, t2 and t3 also contain a column "ttime", of type timestamp. I would like to modify my insert statement above to only insert data

where t1.ttime > max(t2.ttime)

How can I do this?

Answer 1

with subreq as (select max(time) from t2)
insert into t2 select * from t1 where t1.time>subreq.time

只需进行查询with，然后您就可以引用其中的任何列以供进一步操作