Python's Duck Typing Not General Enough; SQL's Minimally Typed Foreign Keys Not General Enough. Debugging Hilarity Ensues.

The money quote was this "It’s not a big leap then for me to consolidate all three of those into one uber relationship table...".

The question was a good one because it involved the classic higher-order database relationship.

The canonical SQL relationships are binary equi-join relationships that can be …

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