sql - Select data that exists in A but not in B -
imagine have tables:
.
what need data exists in not in b, in case select have return "2".
i've done before, right know can't remember how. suppose this:
select a.* left join b b on b.column = a.column but it's not working. can me, please?
thanks in advance.
you're missing filter:
select a.* left join b b on b.column = a.column b.column null
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