PHP & MySQL® Web Development All-in-One Desk Reference for Dummies®

4.4. Updating Information in a Database

Changing information in an existing row is updating the information. For instance, you might need to change the address of a customer because she moved, or you might need to add a fax number that a customer left blank when he originally entered his information.

4.4.1. Updating information with SQL queries

The UPDATE query is straightforward:

UPDATE tablename SET column=value,column=value,...
        WHERE clause

In the SET clause, you list the columns to be updated and the new values to be inserted. List all the columns that you want to change in one query. Without a WHERE clause, the values of the column(s) would be changed in all rows. But with the WHERE clause, you can specify which rows to update. For instance, to update an address in the Customer table, use this query:

UPDATE Customer SET street="3423 RoseLawn",
                    phone="555-555-5555"
                WHERE lastName="Contrary"

4.4.2. Updating information with phpMyAdmin

In phpMyAdmin, you can update information by displaying the information and changing it directly, as follows:

1. Open the Table page by clicking the name of the table in the left panel.

   If the database containing the table isn't selected, click the database name or select it from the Database drop-down list.

   The Table page opens, displaying a list of the fields in the table.

2. Click the Browse icon at the top of the page.

   All the data in the table is listed in a table of rows and columns.

3. Click the Change icon for the row that you want to update.

   The Change ...