In the last chapter, you learned how to add data to a table. SQL allows you to make changes to data that’s already in a table, and we’ll learn how to do that in this chapter.
Why would you want to update data after it’s been added? Perhaps you made a mistake with the data when running the INSERT statement, such as spelling a name wrong or adding the wrong date. Or perhaps part of an application makes a change and needs to update the data. Or perhaps a user of the application changes some data and wants to save it. Each of these will involve an update to the data in ...
