Here are the steps to creating a view in PeopleSoft of data that exists in a database table that is external to your PeopleSoft database.
1. Create a view in the external database of the data you need access to in PeopleSoft.
2. Create a view in the PeopleSoft database of the view that you created in step 1.
3. Create a view record in App Designer of the view you created in step 2.
4. Build your view record in App Designer
5. Save your scripts from steps 1 and 2 so that you can use them to create the same views in the other database environments in your development path when you migrate your new project forward to production.
Using Oracle SQL notation, and using the view Y_ACAD_PROG_VW for my example, I'll explain steps 1 thru 3 below. (To clarify: this process works just as well if the external database happens to be a PeopleSoft database itself.)