Tag: database

Changing the Name and Path of the Active WordPress Theme Without Breaking Theme Settings

After changing a brand name, but little else, on a WordPress site we can end up with a WordPress theme called “oldbrand” on a site called “New Brand.” This leads to weird things like the brand’s logo being at the URL newbrand.com/wp-content/themes/oldbrand/img/newbrand-logo.png. Oops. SEOs must cry a little when they see something like that. This is a situation one of my clients ended up in after a name change, but it ends now.

We can’t simply change the theme directory from themes/oldbrand to themes/newbrand and update the active theme in the Appearance section of the wp-admin because theme-related settings are tied to the theme directory in the database. This includes things like widget placement; a different theme probably has very different widget areas so widget placement should be stored per-theme. The same goes for any theme settings & customizations. To get around this we need to update the database so WordPress thinks that the new theme name is the theme name we’ve always been using.

A word of caution: back up your database before trying this. We’re going to run raw queries. If something breaks you may end up in an in-between limbo, and restoring from backup is the quickest way out.

After diving through the database of a few sites this morning these queries make it possible to rename the theme directory, and optionally rename the theme in style.css:

# Update the main theme options
UPDATE wp_options SET option_value='new-theme-directory' WHERE option_name='template';
UPDATE wp_options SET option_value='new-theme-directory' WHERE option_name='stylesheet';
UPDATE wp_options SET option_name='theme_mods_new-theme-directory' WHERE option_name='theme_mods_old-theme-directory';

# If also updating the Theme Name in the theme's style.css
UPDATE wp_options SET option_value='New Theme Name' WHERE option_name='current_theme';  

# If any posts reference assets in the theme such as images or logos.
UPDATE wp_posts SET post_content=REPLACE(post_content, 'themes/old-theme-directory', 'themes/new-theme-directory' );
UPDATE wp_postmeta SET meta_value=REPLACE(meta_value, 'themes/old-theme-directory', 'themes/new-theme-directory');

# If WordFence is used
UPDATE wp_wfConfig SET val=REPLACE(val, 'themes/old-theme-directory', 'themes/new-theme-directory');

# Delete a couple of transients that store references to the old theme directory.
DELETE FROM wp_options WHERE option_value='_site_transient_theme_roots';
DELETE FROM wp_options WHERE option_value='_site_transient_update_themes';

Protips:

  • Try to run these queries at nearly the same time as the theme directory is renamed. Bonus points for making a script that does it all nearly instantly.
  • If an installation stores transients somewhere other than the DB, then clearing them in the DB won’t work, (clearing the transients may not be strictly required).
  • The sample code uses the default wp_ table prefix. When working on a site with a different prefix, use that.

Hopefully this helps someone finish their Googling session and get on with a rename!

PHP’s mysql_connect() Reuses Connections by Default

As I mentioned yesterday, I’m doing some work in WordPress right now, and a few minutes ago I tweeted that my custom code is messing with WP’s wp_get_archives() and wp_list_categories() functions, well, I found the problem.

I am including the 4RoadService.com header & utilities files in my WordPress theme, and I am using the same user here on my test server for both the main 4RoadService.com database and the WordPress database. It turns out that when the 4RoadService.com database connection was initialized, since it uses the same connection info as the WordPress database, the existing connection was just reused, (this behaviour, by the way, is well described in the PHP documentation), then when the 4RoadService.com connection was told to use the main 4RoadService database it did, thus switching our one and only connection away from the WordPress database, and making WordPress think that there were no posts on the blog.

Fortunately, there is a quick workaround, just add one more attribute to the mysql_connect() function so it looks like this:

$dblink = mysql_connect($host, $user, $pass, true);

This way a new connection is established, and the WordPress connection is left alone.

I am left wondering why, in the loop, WordPress was able to see my posts, perhaps it establishes a second database connection in there. However, I’m not going to spend the afternoon poking through the guts of WordPress.