SQL Queries for Mere Mortals: A Hands-On Guide to Data Manipulation in SQL, Second Edition

What Is a DELETE?

You learned in the previous chapter that adding data to your tables is fairly straightforward. You can add one row at a time by using a VALUES clause, or you can copy multiple rows by using a SELECT expression. But what do you do if you added a row in error? How do you remove rows you’ve copied to archive tables? How do you delete a customer who isn’t sending you any orders? How do you remove a student who applied for admission but then didn’t sign up for any classes? If you want to start over with empty tables, how do you remove all the rows? The answer to all these questions is this: Use a DELETE statement. Just like all the other statements in SQL, a DELETE statement works with sets of rows. As you’ll learn in this chapter, ...