any is used with <, >, =, and a subquery. It returns results when any value retrieved in the subquery matches the value in the where or having clause of the outer statement. all is used with < or > and a subquery. It returns results when all values retrieved in the subquery are less than (<) or greater than (>) the value in the where or having clause of the outer statement. See Chapter 5, “Subqueries: Using Queries Within Other Queries.”
in returns results when any value returned by the second expression matches the value in the first expression. The second expression must be a subquery or a list of values enclosed in parentheses. in is equivalent to = any.
