Why does WHERE email = NULL return zero rows?
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Why does WHERE email = NULL return zero rows?
Why does WHERE email = NULL return zero rows — even when half your users actually have a NULL email? NULL doesn't mean empty string. NULL means unknown. In SQL's three-valued logic, NULL = NULL is itself UNKNOWN, and the WHERE clause treats UNKNOWN like FALSE. Every row's filter check fails — even the rows where email really was NULL. The ...
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