MySQL 4.1 MySQL Version 4.1 includes support for SQL subselects, also called subqueries or nested queries, a powerful feature that lets users search complex data with ease and efficiency. With subselects, users can achieve query consolidation by nesting one query inside another query, creating a resource otherwise unavailable for searching in a single statement. Subselects allow users to query within a result set, creatively limit the result set or correlate results with an otherwise unrelated query in a single call to the database.