How to Create SQL Sub Query in PHP/MySQLi Tutorial Submitted by nurhodelta_17 on Thu, 08/05/2021 - 11:12 A tutorial that tackles about SQL Subquery. Sub query is a query within another SQL query. Subqueries can be used with the 4 SQL methods which are SELECT, INSERT, UPDATE, and DELETE. Read more about How to Create SQL Sub Query in PHP/MySQLi TutorialAdd new comment2474 views