At the beginning of this lesson, you knew how to use the basic SELECT and FROM clauses. Now you know how to use a host of operators that enable you to fine-tune your requests to the database. You learned how to use arithmetic, comparison, character, logical, and set operators. This powerful set of tools provides the cornerstone of your SQL knowledge. In Lesson 4, you learn to increase the data-mining power of the SQL query by integrating other clauses such as the WHERE clause into your queries to perform operations involving grouping and ordering.