Explain Meta.connection

[janus]

Could you example the below?

return cls.Meta.connection.cursor()

I don't really understand where Meta.connection gets it methods.

[pwoolcoc]

In the example from the README, we see this:

class Meta:
    connection = sqlite3.connect(":memory:")

defined within the Model subclass. What this does is define another class as a class attribute of the Model subclass. This other class, Meta, that can be accessed from cls.Meta within classmethods. The Meta class then has a class attribute, connection. When the user (user being the programmer using this ORM) defines a new model, they have to provide an active database connection to their Model subclass. That is what the above code is doing. The sqlite3.connect method returns a connection to an in-memory sqlite database. The Model subclass then uses that connection to persist data.

The cursor() method on the Meta.connection object returns a database cursor for the database connection. You can find more information about the python sqlite module here: http://docs.python.org/library/sqlite3.html

[skorokithakis]

Sorry, yes, @pwoolcoc's explanation is exactly correct. It's just how configuration for the ORM is stored, it's not entirely elegant as some class attributes get lost when redefining the meta class, but I probably need to add some code to put them back on initialization (for example, it shouldn't fail if indexes is missing).