Alias._copy_internals raises AttributeError

[Former user]

Found in 0.5.6, also appears to be present in trunk.

The implementation of the offending method includes::

baseselectable = baseselectable.selectable

which causes "AttributeError: 'Alias' object has no attribute 'selectable'" to be raised.

Looking at the implementation of __init__, shouldn't it be::

baseselectable = baseselectable.element

I only noticed this when I had aliases of aliases. Unfortunately, I was not able to make a small test case that exposes this issue, even with the aliases of aliases.

[Mike Bayer]

sorry, what line of code are you looking at ? here is 0.5 branch:

 def __init__(self, selectable, alias=None):
        baseselectable = selectable
        while isinstance(baseselectable, Alias):
            baseselectable = baseselectable.element
        self.original = baseselectable
        self.supports_execution = baseselectable.supports_execution
        if self.supports_execution:
            self._autocommit = baseselectable._autocommit
        self.element = selectable
        if alias is None:
            if self.original.named_with_column:
                alias = getattr(self.original, 'name', None)
            alias = _generated_label('%%(%d %s)s' % (id(self), alias or 'anon'))
        self.name = alias

here is trunk:

    def __init__(self, selectable, alias=None):
        baseselectable = selectable
        while isinstance(baseselectable, Alias):
            baseselectable = baseselectable.element
        self.original = baseselectable
        self.supports_execution = baseselectable.supports_execution
        if self.supports_execution:
            self._autocommit = baseselectable._autocommit
        self.element = selectable
        if alias is None:
            if self.original.named_with_column:
                alias = getattr(self.original, 'name', None)
            alias = _generated_label('%%(%d %s)s' % (id(self), alias or 'anon'))
        self.name = alias

no access of baseselectable.selectable. that's from an old version of SQLA so I think you have some files mixed up.

[Former user]

Sorry for the misleading snippet: the line of code I'm looking at is in Alias._copy_internals (lines 2657-2659 in 0.5.6):

        baseselectable = self.element
        while isinstance(baseselectable, Alias):
            baseselectable = baseselectable.selectable

When I referred to the __init__ method, I meant that it has similar code that works correctly (lines 2621-2623 in 0.5.6):

        baseselectable = selectable
        while isinstance(baseselectable, Alias):
            baseselectable = baseselectable.element

So, it looks like Alias._copy_internals should use baseselectable.element instead of baseselectable.selectable in the while loop.

[Mike Bayer]

OK, thanks. You'd probably get that issue in conjunction with query.join() or eagerloads - if you can send me a stack trace I can produce a test from that.

[Mike Bayer]

b9657c763a88921ab456992f061a52b4fe08deb2 ee9d7372cb51f48bafc3166f3fc0d678282f3910

[Mike Bayer]

Removing milestone: 0.5.7 (automated comment)