Database Redesign
The NOT EXISTS keyword will be true if:

all rows in the subquery fail the condition.
both of these two conditions are met.
neither of these two conditions is met.
any row in the subquery meets the condition.

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Database Redesign
The EXISTS keyword will be true if:

any row in the subquery meets the condition only.
neither of these two conditions is met.
all rows in the subquery fail the condition only.
both of these two conditions are met.

ANSWER DOWNLOAD EXAMIANS APP