The update statement replaces values in specified columns of a database table with new values. These new values can come from any of the following places:

You can update all the rows in a table. For example, assume that you want to change to five-digit account numbers for customers. The following statement updates all existing account numbers in the customer table by adding 10000 to each number:

Using the where clause, you can update only selected rows. The following example updates only the customer who meets the criteria defined in the where clause:

There are also query object and cursor versions of the update statement. Both of these update operations modify the values in the current row when the statement is executed. For examples of query object and cursor update statements, see How You Can Use Query Objects and How You Can Use Cursors to Access the Database.