At the beginning of today, 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. On Day 4, you will learn to increase the data-mining power of the SQL query by integrating functions that allow you to manipulate the appearance of the data sets returned.