Sams Teach Yourself Microsoft

Lesson 19. Updating and Deleting Data

In this lesson, you will learn how to use the UPDATE and DELETE statements to enable you to further manipulate your table data.

Updating Data

To update (modify) data in a table, you use the UPDATE statement. UPDATE can be used in two ways:

• To update specific rows in a table

• To update all rows in a table

Caution: Don’t Omit the WHERE Clause

Special care must be exercised when using UPDATE because it is all too easy to mistakenly update every row in your table. Be sure to read this entire section on UPDATE before using this statement.

Tip: UPDATE and Security

Use of the UPDATE statement can be restricted and controlled. More on this in Lesson 29, “Managing Security ...