The Custom OData Entity Keys dialog box opens.
The following image shows the Custom OData Entity Keys dialog box:
On the left side, you see three types of entities:
Entities that do not have a primary key.
Entities that do not exist but still have a custom key mapped to them.
Entities that have a primary key defined, and do not require a custom composite key.
On the right side, you see a list of fields that you can map to create a custom composite key.