define('WP_HOME','http://example.com');
define('WP_SITEURL','http://example.com');

UPDATE wp_options SET option_value = replace(option_value, 'http://www.olddomain.com/', 'http://www.newdomain.com/') WHERE option_name = 'home' OR option_name = 'siteurl';

UPDATE wp_posts SET guid = replace(guid, 'http://www.olddomain.com/','http://www.newdomain.com/');

UPDATE wp_posts SET post_content = replace(post_content, 'http://www.olddomain.com/', 'http://www.newdomain.com/');

UPDATE wp_postmeta SET meta_value = replace(meta_value, 'http://www.olddomain.com/', 'http://www.newdomain.com/');