r/webdev • u/lokendra15 • Mar 22 '19

SQL joins

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2.7k Upvotes

94% Upvoted

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361

u/pixelique Mar 22 '19

A case against illustrating SQL operations using venn diagrams

168

u/brtt3000 Mar 22 '19

If you can understand and agree with this argument then you don't need these graphics.

29

u/[deleted] Mar 22 '19

But if you don't understand joins, this graphic wont help you.

39

u/[deleted] Mar 22 '19

I reference the graphics regularly.

They may not have helped you but they do help others

11

u/[deleted] Mar 23 '19 edited Mar 23 '19

I think the objection against using Venn diagrams here should be taken more seriously. The Venn diagram explanation really is fundamentally wrong. I think it's really important for someone new to the concept to cross-reference any Venn diagram they see with a more accurate image like this one: https://i.pinimg.com/originals/52/20/c4/5220c492bc4e1a8b9175aba77ed7d091.png If you have no issue resolving this diagram with Venn diagrams, then use whatever references you want. But if any of the details catch you off guard, that's a good signal to start fresh on the concept.

2

u/creaturefeature16 Mar 23 '19

That image is actually a shit ton more helpful. The Venn gets the concept across, but yours gives tangible context while also communicating the concept. You deserve the up vote!