The best way is to get the entity definition in an XML format and use the button ‘Import web services/XML file that is available in each domain model:
Another option is useful when you can only retrieve the domain model as an Excel, probably with one entity on each worksheet. Then you can create a new Mendix app by going to new.mendix.com and click on this option:
Finally I find an interesting way to complete it, Use JSON structure & ‘import mapping’ to automatically create non-persistable entities.
Easy to get Json data from DB. Almost all DB support Json query, take postgresql as an example
select row_to_json(t) from ( select * from inventory) t ; it returns {"id" : "cherry", "balance" : 316}
User the Json data to create a Json structure from Studio Pro.
Create ‘Import Mapping’ from Studio Pro, use ‘map automatically’ it will create non-persistable entity.