SQL UPDATE Statement

The UPDATE statement is used to update records in a table.

The UPDATE Statement

The UPDATE statement is used to update existing records in a table.

SQL UPDATE Syntax

UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value

Note: Notice the WHERE clause in the UPDATE syntax. The WHERE clause specifies which record or records that should be updated. If you omit the WHERE clause, all records will be updated!

SQL UPDATE Example

The "Persons" table:

Now we want to update the person "Tjessem, Jakob" in the "Persons" table.

We use the following SQL statement:

UPDATE Persons
SET Address='Nissestien 67', City='Sandnes'
WHERE LastName='Tjessem' AND FirstName='Jakob'

The "Persons" table will now look like this:

SQL UPDATE Warning

Be careful when updating records. If we had omitted the WHERE clause in the example above, like this:

UPDATE Persons
SET Address='Nissestien 67', City='Sandnes'

The "Persons" table would have looked like this:

Learn how your website performs under various load conditions

WAPT is a load, stress and performance testing tool for websites and web-based applications. In contrast to "800-pound gorilla" load testing tools, it is designed to minimize the learning curve and give you an ability to create a heavy load from a regular workstation. WAPT is able to generate up to 3000 simultaneously acting virtual users using standard hardware configuration. Virtual users in each profile are fully customizable. Basic and NTLM authentication methods are supported. Graphs and reports are shown in real-time at different levels of detail, thus helping to manage the testing process. Download the free 30-day trial!

Jump to: Top of Page or HOME or Printer friendly page

W3Schools provides material for training only. We do not warrant the correctness of its contents. The risk from using it lies entirely with the user. While using this site, you agree to have read and accepted our terms of use and privacy policy.

Copyright 1999-2009 by Refsnes Data. All Rights Reserved.

W3Schools was converted to XHTML in December 1999