Since by far the most errors I see in SQL queries are places where Venn diagrams do not accurately describe SQL behavior... yeah, I'm gonna have to agree, though I'm not sold on the alternative here. Like 90%+ of the flaws I run across in queries are due to multiple matching rows on the right side, without `distinct` or an aggregation of some kind.
1:1 matches on rows are trivial. Venn diagrams can describe these too. But you really can't let people develop an intuition based on that, early on, or they kinda get stuck and it takes a while to unravel.
1:1 matches on rows are trivial. Venn diagrams can describe these too. But you really can't let people develop an intuition based on that, early on, or they kinda get stuck and it takes a while to unravel.