Geekality » WordPress

SQL for listing all WordPress tags

Torleif — Mon, 13 Jun 2011 20:47:17 +0000

When writing a post I sometimes find it difficult to choose what I should tag it with. I try reuse tags I already have to prevent a total mess, and sometimes I just don’t really remember what tags I have used so far. When writing a post in WordPress you can get a list of the most used ones, but once in a while I write a post on subject I haven’t written a lot about. So, instead of going to the Post Tags page and look through all the pages of tags, I decided to just connect to my blog database and run a query.

SELECT name, slug, description, COUNT FROM wp_terms
NATURAL JOIN wp_term_taxonomy
WHERE taxonomy="post_tag"
ORDER BY name

Lists all your tags, sorted by name

Some speedy WordPress fixes

Torleif — Fri, 03 Jun 2011 20:41:51 +0000

Used Page Speed for FireFox the other day to analyze my blog. Found a couple of issues and a couple were very simple to fix. If these will work for you, depends a bit on where your WordPress site is hosted and what your web server does already. So, be brave and analyze your own site. Look through the results and see if you can fix some of it without too much hassle

Missing expiration date and unnecessary ETag

The browser caches stuff, and to do that it needs some information. When we have stuff that doesn’t change very often (if ever) we should tell the browser that, once you’ve downloaded this, you don’t really need to check back for a new version for a while. To do this we add an expiration date. In addition you have two headers called Last-Modified and one called ETag. you can read more about that and all the rest of this in the link earlier in this paragraph, but the short story is you should have one. Having both is just not necessary. When I checked the headers sent with my images, I found that both were sent. So I decided to turn off the FileETag. To do all of this, for images, javascript files and stylesheets, I added the following lines to the .htaccess file in the root of my WordPress blog:

ExpiresActive On
ExpiresDefault "access plus 2 weeks"
FileETag none

More info

Enable Compression

Compressing stuff means less data has to go across the wire between the browser and the web server. Which is generally a nice thing. And as long as the web server supports it, enabling it is pretty simple. Just add the following line to your .htaccess file.

AddOutputFilterByType DEFLATE text/html text/plain text/xml text/javascript text/css application/javascript

More info

Don’t touch the default stuff

Just to make it less likely that someone messes up their WordPress installation after reading this: Make sure you add the above stuff. Do not just replace the .htaccess file. WordPress comes with an .htaccess file, and what’s in there needs to be there. Here is how the default stuff looks in mine:

# BEGIN WordPress

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

# END WordPress

Unless you know what you’re doing, it’s probably a good idea to not touch any of that And if you do end up messing up your WordPress blog after reading this blog post, don’t blame me

This blog post can make WordPress crash

Torleif — Mon, 18 Oct 2010 21:17:09 +0000

Was writing a blog post today. Happy, typing away. Hit Preview, and *bam*:

Service Temporarily Unavailable

The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

Say wahaat? Strange thing was my website was otherwise working normally. Could even edit other posts just fine!

Some head scratching, googling and making a support request to Dreamhost followed. Apparently they had just had an outtake, so I figured it might be related. They did too. But it was not! I finally found the answer on a blog:

Turns out this error is not alone in WordPress and not a bug of it at all. Some of the administration tasks of other CMS software such as posting posts with PHP code in them and uploading stuff would also trigger a module in Apache called Mod_security to be over sensitive. — www.kavoir.com

And sure enough, I had mentioned a PHP function called curl_exec in my blog post. Once I removed that word, the post could be previewed and saved just fine. Great stuff…

Solution

Of course I could just have avoided using that word, but that’s no fun. After reading the rest of that mentioned blog post, some comments and wiki page at Dreamhost, I found that by adding the lines below to the .htaccess file the problem was fixed. Or makes it go away at least

SetEnvIfNoCase Request_URI ^/wp-admin/(?:post|async-upload)\.php$ MODSEC_ENABLE=Off
SetEnvIfNoCase Request_URI ^/xmlrpc\.php$ MODSEC_ENABLE=Off
SecFilterDebugLevel 0
SecFilterDefaultAction "deny,nolog,noauditlog,status:503"

Alrighty… back to my actual blog post…

How to delete WordPress post revisions

Torleif — Tue, 20 Oct 2009 21:40:23 +0000

Having revisions on my posts is nice I suppose. But I was starting to get a bit annoyed with the increasingly long list of revisions in each post. And they really did get long. Mainly because I am in a bit of a testing and experimenting phase which means that I have done a lot of adjustments to almost every single post so far because I don’t have 100% control on how I want things or how things will end up looking and so on There’s also of course all the obligatory spelling errors I only discover after I have clicked Publish

Anyways, I found a nice little MySQL snippet to clear out all of them in a French comment to a blog post. Thought I could share it here. That way I won’t lose it either

DELETE x,y,z
FROM wp_posts x
LEFT JOIN wp_term_relationships y ON (x.id = y.object_id)
LEFT JOIN wp_postmeta z ON (x.id = z.post_id)
WHERE x.post_type = 'revision'

You can swap delete x,y,z with select * to check that it will delete what you really want to.

Remember that if you have a table prefix other than ‘wp_’ set in your wp-config.php, you need to change that in your SQL script before you run it. The line looks like this in my config file:

$table_prefix = 'wp_';

I can also recommend setting WP_POST_REVISIONS to something in your wp-config.php file. Just search for REVISIONS in that file. If you don’t find it, you can just add it somewhere. The line should look like the following, where N would be how many revisions you want to allow, or -1 if you want them all:

define('WP_POST_REVISIONS', N);

I will still run the SQL script once in a while though, cause after a while my posts become sort of stable, and having revisions with my spelling errors hanging around for ever doesn’t really make sense in my head