MySQL replace

MySQL replace example:

UPDATE `wp_options` SET `option_value` = REPLACE(`option_value`, 'www.site.com', 'www.new.com');
UPDATE `wp_posts` SET `post_content` = REPLACE(`post_content`, 'www.site.com', 'www.new.com');
UPDATE `wp_comments` SET `comment_author_url` = REPLACE(`comment_author_url`, 'www.site.com', 'www.new.com');

You can change links or any other strings in you database in such way.