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A Visual Explanation of SQL Joins

I thought Ligaya Turmelle's post on SQL joins was a great primer for novice developers. Since SQL joins appear to be set-based, the use of Venn diagrams to explain them seems, at first blush, to be a natural fit. However, like the commenters to her post, I found that the Venn diagrams didn't quite match the SQL join syntax reality in my testing.

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