Synchronizing the External Entity Type
You can use the OData Sync feature to synchronize the properties of a selected external entity type with the latest changes made at the external source provider level. You can also use the Sync feature to edit the properties of an external entity type.
To sync and edit an external entity type
1. In the Package Navigator view, navigate to and open the OData service which contains the external entity that you want to edit. The OData service opens in the OData service editor.
2. Select the external entity that you want to edit and click the Sync icon 
on the Designer toolbar or right-click and select Sync. 3. In the External Entity Sync dialog box, you can make the following modifications to the selected external entity:
Select new properties available for the entity.
Remove the existing properties.
Change the data type for the
Java Type.
Click the key icon to make or remove a property as primary key.
4. When you finish making changes to the external entity, click Sync.
The updated the external entity is displayed in the OData service editor.