MYSQL/PHP: How do you Order By Starting point in a string?

 SELECT
      SQL_CALC_FOUND_ROWS posts.*,
      CASE
        WHEN postmeta.meta_value REGEXP '$regex'
          THEN 1
          ELSE 0
        END AS keyword_in_title,

      MATCH ( posts.post_content )
        AGAINST ( '".addslashes( $s )."' ) AS mysql_score
    FROM
      $wpdb->posts as posts,
      $wpdb->postmeta as postmeta
    WHERE
      posts.post_date_gmt <= now()
      AND postmeta.post_id = posts.ID
      AND postmeta.meta_key='_headspace_page_title'
      AND posts.post_password = ''
      AND posts.post_status = 'pub开发者_如何学编程lish'
      AND posts.post_type != 'attachment'
      AND ( postmeta.meta_value REGEXP '$regex'
        OR posts.post_content REGEXP '$regex')
    GROUP BY
      posts.ID
    ORDER BY
      charindex($s, 'keyword_in_title') DESC
    LIMIT 
      $offset, 
      $limit

As to the order issue (Apart from the escaping issue @Gumbo pointed out in the comment), CHARINDEX is not a valid mysql string function. The LOCATE function looks to be identical (at least from a cursory glance between the docs on SQLServer and MySQL)...

$s = mysql_real_escape_string($s);
$order = 'ORDER BY LOCATE(\''.$s.'\', `keyword_in_title`) DESC';

I'm assuming that the code above does not work and hence you're asking a question.

Try adding charindex($s, 'keyword_in_title') AS cOrder in your SELECT clause and then ORDER BY cOrder DESC

Good luck!