Note that it may be a historical model, and thus not have any custom attributes, methods, or When model_name is set, hints normally contains the model class Hints are used by certain operations to communicate additional Model._meta.model_name (the lowercased version of the model Model_name is set by most migration operations to the value of The app_label positional argument is the label of the application Shouldn’t run, or None if the router has no opinion. Return True if the operation should run, False if it allow_migrate ( db, app_label, model_name = None, ** hints ) ¶ĭetermine if the migration operation is allowed to run on the database withĪlias db. Relations within the same database are allowed. Relation should be allowed between two objects. Used by foreign key and many to many operations to determine if a Return True if a relation between obj1 and obj2 should beĪllowed, False if the relation should be prevented, or None if allow_relation ( obj1, obj2, ** hints ) ¶ Suggest the database that should be used for writes of objects of Information that might assist in selecting a database, it will be If a database operation is able to provide any additional Suggest the database that should be used for read operations for Database routers ¶Ī database Router is a class that provides up to four methods: db_for_read ( model, ** hints ) ¶ If you want to implement more interesting database allocationīehaviors, you can define and install your own database routers. – it is provided ‘out of the box’ on every Django project. You don’t have to do anything to activate the default routing scheme Routing scheme ensures that if a database isn’t specified, all queries The foo database will be saved on the same database). ‘sticky’ to their original database (i.e., an object retrieved from The default routing scheme ensures that objects remain The easiest way to use multiple databases is to set up a database By default, it checks only the default database,īut it consults the allow_migrate() method of routers if any are installed. Validates the migration history in the databases to catch problems with theĮxisting migration files (which could be caused by editing them) beforeĬreating new migrations. The same way as migrate – they only ever operate on one database atĪ time, using -database to control the database used.Īn exception to this rule is the makemigrations command. Most other django-admin commands that interact with the database operate in
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