Creating an anonymous CTE with an Update causes AttributeError

[Jack Zhou]

Test case:

class Foo(Base):
    __tablename__ = "foo"
    id = Column(Integer, primary_key=True)

foo = Foo.__table__
q = foo.update().returning(foo.c.id).cte()

Stack trace:

Traceback (most recent call last):
  File "sqlite.py", line 32, in <module>
    main()
  File "sqlite.py", line 28, in main
    q = foo.update().returning(foo.c.id).cte()
  File "/home/jack/dev/sqlalchemy/lib/sqlalchemy/sql/selectable.py", line 1588, in cte
    return CTE(self, name=name, recursive=recursive)
  File "/home/jack/dev/sqlalchemy/lib/sqlalchemy/sql/selectable.py", line 1386, in __init__
    super(CTE, self).__init__(selectable, name=name)
  File "/home/jack/dev/sqlalchemy/lib/sqlalchemy/sql/selectable.py", line 1235, in __init__
    if self.original.named_with_column:
AttributeError: 'Update' object has no attribute 'named_with_column'

[Mike Bayer]

Ensure DML provides named_with_column for CTE(Alias)

Fixed bug in new CTE feature for update/insert/delete whereby an anoymous (e.g. no name passed) :class:.CTE construct around the statement would fail. The Alias base class of CTE checks for the "named_with_column" attribute in order to detect if the underlying selectable has a name; UpdateBase now provides this as False.

Change-Id: I4b0309db21379a4c0cb93085298c86da3cf840e4 Fixes: #3744

→ <<cset 889c011a0f7b>>