Method _nodb_cursor

django/db/backends/postgresql/base.py:517–552

(self)

    @contextmanager
    def _nodb_cursor(self):
        cursor = None
        try:
            with super()._nodb_cursor() as cursor:
                yield cursor
        except (Database.DatabaseError, WrappedDatabaseError):
            if cursor is not None:
                raise
            warnings.warn(
                "Normally Django will use a connection to the 'postgres' database "
                "to avoid running initialization queries against the production "
                "database when it's not needed (for example, when running tests). "
                "Django was unable to create a connection to the 'postgres' database "
                "and will use the first PostgreSQL database instead.",
                RuntimeWarning,
            )
            for connection in connections.all():
                if (
                    connection.vendor == "postgresql"
                    and connection.settings_dict["NAME"] != "postgres"
                ):
                    conn = self.__class__(
                        {
                            **self.settings_dict,
                            "NAME": connection.settings_dict["NAME"],
                        },
                        alias=self.alias,
                    )
                    try:
                        with conn.cursor() as cursor:
                            yield cursor
                    finally:
                        conn.close()
                    break
            else:
                raise

    @cached_property
    def pg_version(self):