If you’re migrating domains, changing your alias, or simply learned the hard lessons between your, you’re, you are, here’s a simple mysql query to run on your database.
[box type=”note”]Be sure to backup your database![/box]
You will need phpMyAdmin or SQL Executioner. A basic knowledge in SQL is a must, so run down to Barns & Noble and get your nerd on!
update wp_posts set post_content = replace(post_content,’myoldsite.com’,’mynewsite.com’)
In this example, we are targeting wp_posts -> post_content. We are performing replace() on anything in post_content that matches “myoldsite.com”.
The basic logic can be applied to anywhere in the database, but this is very useful if for example, all your posts pointed to a site that no longer exists. I’ve also used this to remove author’s contact information in the content. For some reason they thought it was a good idea to include their phone number and e-mail on every post, which later became outdated! I eventually crated a useful author signature and a way they could update this information in /wp-admin/profile.php.