UPDATE wp_posts SET post_content = replace( post_content, 'AAA.com','BBB.com');

UPDATE wp_comments SET comment_content = replace(comment_content, 'AAA.com', 'BBB.com');

UPDATE wp_comments SET comment_author_url = replace(comment_author_url, 'AAA.com', 'BBB.com');

UPDATE wp_options SET option_value = replace( option_value, 'AAA.com','BBB.com');