Contains the class Relations that stores relations between models and joins them together appropriately.
Stores relations of models and has the ability to join them.
Execute the the SQL JOIN and create a table thereof.
Get all models related to
modelof a superclass.
Determine whether the relation_map is a tree.
Perform some setup and then call the depth first search, starting from an arbitrary node.
Returns: bool – True if the graph is a tree. If it contains at least on cycle or is not connected, return False.
Start the join process between all models.