Define a Primary and a Parent Entity Schema

An example of this would be where you have 2 files one for Opportunities and a second for Accounts.  In this case, the Primary Entity is OPPORTUNITY and the second Entity is ACCOUNT and they have a relationship.

1. Press the Options button in the top left of the Navigation Bar and select Schemas
2. Press Create Schema button
3. Give the Schema a name - e.g. Opportunity and Account
4. Select Other as the Source
5. Press Add Primary Entity button
6. Add the Primary Entity Name - eg OPPORTUNITY and specify a Primary Entity Label
7. Specify the column name that is unique for each row as the Primary Key
8. Specify the Sort Order - suggest the is left blank
9. Press the Add Entity button
10. Add the Secondary Entity Name - eg ACCOUNT and specify a Primary Entity Label
11. Specify the column name that is unique for each row as the Primary Key
12. Specify the Sort Order - suggest this is left blank
13. Press the Next button
14. Press the Add Relationship button
15. Select ACCOUNT as the Entity
16. Select OPPORTUNITY as the Related Entity
17. Specify the column on the OPPORTUNITY Entity that is the Foreign Key to ACCOUNT - eg ACCOUNTID
18. Press the Create button
19. Drill on the Schema and the overview should look like this