Subquery
SQLA query nested inside another query. Can appear in FROM (derived table), WHERE (scalar or correlated subquery), or SELECT (scalar subquery). Correlated subqueries reference the outer query and execute once per outer row.
A query nested inside another query. Can appear in FROM (derived table), WHERE (scalar or correlated subquery), or SELECT (scalar subquery). Correlated subqueries reference the outer query and execute once per outer row.