SQL Job need to target web.config file for its target DB.

How can we configure the SQL job that it would target the web.config file for the DB to target.

Example:

I have 2 DB's - DB1 and DB2

and jobs are configured to fetch data and make changes to data from DB1 and it will only use DB1 only.

Now, whenever i change the DB to DB2 in config file, jobs can't fetch the data from DB2 as they will fetch the data from DB1 only.

Is there any solution, where, whenever I change the DB in config file, the job will target to that DB only?