How to use Variables in hive?

Question

I am trying to use variables in my Hive script. But for some reason it isn't working.

SET $app_count=select max(app_id) from app_table;
SELECT '${hiveconf:app_count}',app_name,ROW_NUMBER() OVER (ORDER BY app_name) FROM new_apps;

Output

_c0   app_name    _wcol0
      app1          1
      app2          2
      app3          3

Expected result: lets say the max(app_id) from another table is 10

_c0   app_name    _wcol0
 10    app1         1
 10    app2         2
 10    app3         3

Not sure why the variable value is not substituting in the query. I even used the setting

'set hive.variable.substitute=true;' . But it didn't make any change. Thanks in Advance. Any alternate solution is also appreciated.

Answer 1

Just store the result of this query in another table(test) with single column app_id.

select max(app_id) from app_table

Then you can use the below query:

select test.app_id,new_apps.app_name,ROW_NUMBER() OVER (ORDER BY new_apps.app_name) FROM new_apps join test;