django1/django/db/models/sql/datastructures.py

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"""
Useful auxiliary data structures for query construction. Not useful outside
the SQL domain.
"""
class EmptyResultSet(Exception):
pass
class MultiJoin(Exception):
"""
Used by join construction code to indicate the point at which a
multi-valued join was attempted (if the caller wants to treat that
exceptionally).
"""
def __init__(self, names_pos, path_with_names):
self.level = names_pos
# The path travelled, this includes the path to the multijoin.
self.names_with_path = path_with_names
class Empty(object):
pass