B1if: B1 to DB questions

I'm trying to build an update based on if an item exists on a separate SQL database. I went through all of the webinars, and there's nothing about B1 to DB. There's a DB to B1, which is helpful, but I didn't know if I could just reverse the process and use that, or take an already existing package step and modify it to do the query/update to the SQL table. Again, I need to update/insert to a non SAP B1 table with B1 data based on that non SAP B1 table already having the information. If anyone could help, or point me in the right direction, that would be helpful. Thank you.