Multiple choice technology databases

A NOT IN query will return rows if a NULL value is in the subquery or IN list

  1. True

  2. False

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When a NULL value appears in a NOT IN subquery or list, the entire condition evaluates to UNKNOWN for all rows because comparing any value to NULL (except with IS NULL) returns UNKNOWN, which falsifies the AND condition. This causes the query to return zero rows, not any rows as the statement suggests.