WP SQL – Get rid of all unused shortcodes

I love WordPress shortcodes, but there’s a problem with them: Once you stop using a shortcode (for example when you switch to another theme) you’ll find shortcodes in full text on your posts. Here’s a SQL query to remove them. Just update the code with the shortcode you want to remove. I’ve used [tweet] in this example.

UPDATE wp_post SET post_content = replace(post_content, '[tweet]', '' ) ;

→ Source: http://www.wprecipes.com/wordpress-tip-get-rid-of-unused-shortcodes