I am trying to create a procedure that choose columns dynamically from two table. I have already hardcoded query which works fine.

#Existing query

create table mydb.result_table as 
select 
t1.id,
t1.name,
t1.place,
t1.product
t1.prize
t2.id,
t2.name,
t2.place,
t2.product,
t2.prize
from source_db.source_table t1
full outer join target_db_target_table t2 on 
t1.id=t2.id and t1.name=t2.name
where t1.place<>t2.place

Now i need to create a procedure which basically select column dynamically from given table name and join both with given keys

so something like below

CREATE OR REPLACE PROCEDURE result(source_db varchar, source_table VARCHAR, targt_db varchar, target_table VARCHAR, key_join varchar<not sure can pass list>, filter_col varchar )
returns string not null
language javascript
as
$$
var query= `create table mydb.result_table as 
select
t1.<all columns from source_db and source_table>
t2.<all columns from targt_db and target_table >
from <source_db and source_table> as t1
full outer join  <target_db_target_table> as t2
on <key_join> where <t1.filter_col <> t2.filter_col>
`
return 'success';
$$;

i don't see example of selecting columns dynamically for this kind of use case. Any solution to this?