Subqueries - Oracle PL SQL Course - Lesson 8 | SQL courses

Duration: 16:33 min

Summary: The SELECT statement is the most used SQL command. It contains several clauses such as WHERE, FROM, GROUP BY, HAVING, ORDER BY, and others. This video shows how to use a SELECT statement inside another SELECT in such a way that it is called subquery. The video explain the context, the details, the requirements and the usage of subqueries with aggregated functions and with the operators IN(), ANY(), and ALL(). The video also explain that subqueries should be used with caution on specific scenarios and that they can be replaced by a JOIN on specific situations. The examples are shown based on the tables of the HR sample databases provided by Oracle during the installation of the Oracle 11g Express edition.