Support » Installing WordPress » Error establishing a database connection on OS X 10.5

  • Resolved jonokane


    Hello All,
    First, I have done a ton of searching on this topic and I see that I’m not the only one having issues. Unfortunately, I have spent far too much time on this and I’m still scratching my head.

    I am using a fresh install of OS X Leopard, I have PHP 5.2.4 running, MySQL 5.0.51a MySQL Community Server running on top of OS X’s pre-installed Apache. I can parse PHP, and I can connect to my local MySQL server via command line. I installed phpMyAdmin, and that’s running smoothly locally as well (phpMyAdmin is able to connect read/write to/from MySQL).

    I keep getting the “Error establishing a database connection” page when I hit my local wp site. I have a fresh install of WordPress, with a double-triple-checked wp-config.php file. Configured as follows:

    define('DB_NAME', 'dbname');    // The name of the database
    define('DB_USER', 'root@localhost');     // Your MySQL username
    define('DB_PASSWORD', 'xxx'); // ...and password
    define('DB_HOST', 'localhost');    // 99% chance you won't need to change this valu


    I tried changing the ‘DB_HOST’ designation to my machine’s IP, this did not work as well.

    I have also re-assigned the mysql.default_socket php.ini:
    mysql.default_socket = /tmp/mysql.sock

    Additionally, the my.cnf file:


    I have tried restarting all services, re-installing all services (besides apache), and, well, I’m starting to lose hope! I have done wp installs a gazillion times, but never ever had an issue like this!!!! Someone please help! Any smart suggestions are greatly appreciated!

Viewing 15 replies - 1 through 15 (of 21 total)
  • Followup: After spending what seems like an absolutely ridiculous amount of time on this, I have figured out the embarrassingly simple issue.

    localhost != Localhost

    My Mac identifies itself as Localhost, NOT localhost! Learned something extremely obvious…. 🙂

    So the config should look like this:

    define('DB_NAME', 'dbname');    // The name of the database
    define('DB_USER', 'root');     // Your MySQL username
    define('DB_PASSWORD', 'xxx'); // ...and password
    define('DB_HOST', 'Localhost');    // 99% chance you won't need to change this value

    Thanks. I just got stuck on the same thing and your post saved me.

    Wow! Same problem here… I wasted hours on this. Id like to know where the problem lies… One small capitalisation of a letter in the code for the latest release? or a problem with 10.5?

    jonokane, how did you find out?

    Quote: “99% chance you won’t need to change this value”

    More like: “100% chance you will do youre head in trying trying to figure out why your machine wont respond to the the host name “localhost!!!!””

    I did some further testing regarding this issue as follows…

    Im hoping that this isnt a problem with apache. Ive done a bit of checking into my config files and all seems to be normal. (This is starting to bore me why the hell it works with a capital L.

    It seems it must be a problem with the code as I can connect to the target database with the same user name.

    1. Make a clean install of the wordpress-2.3.3.tar that I downloaded from

    2. Copy the files to a new subdirectory to compare with my working install

    3. Go through all the default files checking for any caps mistakes

    Ive tried both solutions with a clean and modified db (sql dump) from a previous install that worked no prob with the host name “localhost” not “Localhost”

    you saved my day after wasting HOURS on this type-case problem! thanks so much!

    Thanks for posting this! The same problem was driving me insane too. I never would have thought to change the name to a capital ‘L’.

    This is definitely a bug in WordPress 2.5, because every other web app I have running on this machine uses “localhost” and it connects to the MySQL server just fine.

    Man I poured over this for hours before finding this post. A local install on 10.4 was so easy, but 10.5 has been a nightmare. Glad to have found a good resources for 10.5 here.


    Good lord! Thanks for this post. That was the problem with mine too. I was so confused.

    Great $DIETY in $AFTERLIFE

    You probably saved me a grand in monitor damage and a couple grand more in emergency room bills. I never woulda figured this one out.

    Many thanks.

    jonokane-karma += 10

    Here too, I lost too many hours on it… Thanks for resolving this!!!

    but I use Mac OS X 10.4, so this can’t be a Leopard-only problem.

    I tried several WP versions so this is also not WP-version specific.

    And, yes, all the other web-apps successfully connected to MySQL.

    Silly. Thanks for the post. Hope it gets fixed soon.

    Am sitting with the same issue, but it is not saved by the capitalization of ‘localhost.

    Yesterday, I was unable to connect to the online-server (I somehow hot into a loop, and instead of displaying the front end, the link redirected to index.html).

    I actually have a site running successfully on a subdomain, and have other blogs all going fine on the same server. All with same version 2.5.1 and similar setup. This is voodoo.

    I have tried the same as suggested above, with new database, clean install, and still no luck.

    I am using WP 2.5.1, and am mega frustrated. The backend seemed to work OK with the old database, but wasn’t fixing permalinks properly.


    This isn’t a WordPress issue, but a Mac issue. The correct solution is to set mysql.default_socket = /tmp/mysql.sock in /etc/php.ini.

    Details at

    MY GOD!!!

    This needs to be stuck to the top!!! I was about to throw my computer out the window!!

    Hello my site ( ) have this problem. How can I optimize to mysql?

Viewing 15 replies - 1 through 15 (of 21 total)
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