We covered additional SQL and SQLPlus commands including grouping and subqueries. The GROUP BY clause is used in collaboration with the SELECT statement to arrange identical data into groups. An example of this command is:
A subquery is a query within another query and embedded within the WHERE clause. A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved. An example of this command is:
We also touched on SQL I/O. As a side note, it would be helpful if the class covered more troubleshooting commands like DESCRIBE as well.