While Progress does not formally have Primary Keys defined per table, it does have INDEXes. You want to ensure that all fields comprising the INDEX are not-nullable or "mandatory" in Progress parlance. Use the following procedure to check the relevant fields:
Login to the machine that hosts your Progress DBMS.
2. cd into the root of the Progress installation.
3 Use the su command to switch to your local progress user.
4. Execute the .profile associated with the progress user.
5. Launch the _progres utility.
6. Use the Tools menu to access the Data Dictionary utility.
7. Expand the Database menu and use Connect to connect to the target database.
8. Expand the Schema menu and select the Index Editor.
9. Select the target table.
10. Review the fields that comprise that table's index.
11. Select GoField.
12. Select Modify.
13. Navigate to the field that you want to check.
14. Look for the field's mandatory property.
15. Ensure the value passed to Mandatory is "yes" and hit F4 to persist your changes.
The above steps (8-15) will need to be repeated for each field in your table's index.