Find/replace text in Wordpress MySQL post table

wp-link-repair.sql

/*
 *  Use mysql dump to back up the wp_posts table (mysqldump -u username -ppassword wp_databasename wp_posts > wp_posts.sql)
 *  Repair your damage with the wp_posts.sql file (mysql -u username -ppassword wp_databasename < wp_posts.sql )
 *  Install lib_mysqludf found here: http://www.mysqludf.org/lib_mysqludf_preg/
 *  Initialize lib_mysqludf functions
 *  Set target regex pattern
 *  Set replacement
 *  Test target regex pattern.  Function returns 1 for success, 0 for an invalid pattern
 *  Test replacement.  Function shows what the results will look like.
 *  Grit your teeth and run the replace.
 */
CREATE FUNCTION preg_capture RETURNS STRING SONAME 'lib_mysqludf_preg.so';
CREATE FUNCTION preg_check RETURNS INTEGER SONAME 'lib_mysqludf_preg.so';
CREATE FUNCTION preg_position RETURNS INTEGER SONAME 'lib_mysqludf_preg.so';
CREATE FUNCTION preg_replace RETURNS STRING SONAME 'lib_mysqludf_preg.so';
CREATE FUNCTION preg_rlike RETURNS INTEGER SONAME 'lib_mysqludf_preg.so';
CREATE FUNCTION lib_mysqludf_preg_info RETURNS STRING SONAME 'lib_mysqludf_preg.so' ;
/* 
  select LIB_MYSQLUDF_PREG_INFO() from dual;
*/

/*
 *  Set pattern and replacement
 *  Mysql escape character is \, so you have to double backslash your 
 *  regex backslashes
 */
select @pattern := "/http:\\/\\/blog\\.oldblog\.com/";
select @replacement := '/blog';

/*
 *  Test pattern
 */
select preg_check(@pattern);


/*
 *  Test replacement
 */
select preg_replace(@pattern, @replacement, post_content) as post from wp_posts where preg_capture(@pattern, post_content) is not null;

/*
 *  Run replacement
 */

/*
 *  Create temp table
 */
DROP TABLE IF EXISTS wp_posts_archive;
create temporary table wp_posts_archive
  select * from wp_posts;

/*  
 *  Post_excerpt tends to be blank, so I like to put something there for
 *  the posts that I've affected.  I'll go back later and clear it out.
 *  It's nice to have the visual confirmation that yes, I did replace
 *  what I meant to replace.
 *  Uncomment the next line to set post_excerpt to 'replace'
 */
update wp_posts l
set
/*  post_excerpt = 'replaced', */
post_content = 
  (
    select preg_replace(@pattern, @replacement, post_content) as post_content
    from wp_posts_archive m
    where preg_capture(@pattern, post_content) is not null
      and l.id = m.id
  )
where preg_capture(@pattern, post_content) is not null
;

/*
 *  Test result
 */
select * from wp_posts;
select preg_capture(@pattern, post_content) as post from wp_posts where preg_capture(@pattern, post_content) is not null;
/*  select * from wp_posts where post_excerpt = 'replaced'; */