> that's not what "relational" means. "relational" means, "a relational database". where we are using SQL statements to deliver data to and from such a database

> that's not what "relational" means. "relational" means, "a relational database". where we are using SQL statements to deliver data to and from such a database. an ORM that does not directly interpret objects along one-to-many collections /many-to-one attributes is still an object relational mapper. It doesn't. It means it works as a virtual object database that honors relationships on the underlying schema. The fact that the schema is relational is an implementation detail. Many ORMs will work with non-relational databases, but will honor underlying relations transparently if they exist, such as eg. SqlAlchemy on MongoDB. An object mapper isn't even a "database-related" technique. Its just a mechanism to map data into objects - ex. JSON deserialization into object attributes is object mapping. When used in conjunction with traditional database mechanisms (such as eg. repository pattern and query builders), can be used to minimize data conversions between systems. > that's a separate concern from object relational mapping. Well, it is because in Django ORM or SqlAlchemy you use differerent declarations of data structures for data received from requests, data passed around and data read from and written to the database. It is actually a very leaky implementation where eg. when designing models you feel like you're working on a business object representation, but in fact you're still catering to implementation details of the relational model, such as primary keys, nullable fields, indexes and so on and so on. > Do you have the notion that ORMs produce objects that aren't compatible with serialization? That is precisely the point. This is not a feature, it is a quite important limitation. If you use data objects, this issue (as well as complex mapping routines) goes away, because then these objects only hold data and not business logic. These concepts aren't really mainstream in python, but are bread and butter in many other languages.