Method check_consistent_history

django/db/migrations/loader.py:344–370

Raise InconsistentMigrationHistory if any applied migrations have unapplied dependencies.

(self, connection)

        self.graph.ensure_not_cyclic()

    def check_consistent_history(self, connection):
        """
        Raise InconsistentMigrationHistory if any applied migrations have
        unapplied dependencies.
        """
        recorder = MigrationRecorder(connection)
        applied = recorder.applied_migrations()
        for migration in applied:
            # If the migration is unknown, skip it.
            if migration not in self.graph.nodes:
                continue
            for parent in self.graph.node_map[migration].parents:
                if parent not in applied:
                    # Skip unapplied squashed migrations that have all of their
                    # `replaces` applied.
                    if self.all_replaced_applied(parent.key, applied):
                        continue
                    raise InconsistentMigrationHistory(
                        "Migration {}.{} is applied before its dependency "
                        "{}.{} on database '{}'.".format(
                            migration[0],
                            migration[1],
                            parent[0],
                            parent[1],
                            connection.alias,
                        )
                    )

    def all_replaced_applied(self, migration_key, applied):
        """