What is an SQL subquery?
1784
24-Aug-2014
Updated on 16-Sep-2020
Sumit Kesarwani
24-Aug-2014An SQL subquery is a means of querying two or more tables at the same time. The subquery itself is an SQL SELECT statement contained within the WHERE clause of another SQL SELECT statement, and separated by being enclosed in parenthesis. Some subqueries have equivalent SQL join structures, but correlated subqueries cannot be duplicated by a join.