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Changing the WordPress $table_prefix - a word of caution

October 2nd, 2008 Leave a comment Go to comments

I just changed the table prefix from "wp_" to "wp_en_us_" to support multiple installs in the same database, one for each locale. This seemed pretty straightforward - just rename the table names and change the table prefix in wp-config.php, right?

Wrong.

The WP code is littered with references to $table_prefix - including columns in the "usermeta" and "options" table. Key columns such as "wp_capabilities" in the "options" table need to be renamed appropriately, or your user roles are totally broken. In "usermeta" you need to make sure the "wp_user_level" and "wp_capabilities" meta_keys are updated too.

Sadly, after spending a couple hours var_dump() and exit()'ing throughout the code I realized the issue. I am not exactly sure the prefix of some of these keys needs to be aligned with the $table_prefix - maybe WPMU uses that or something. But anyway, what an annoying headache.

I am not sure but I think -all- "wp_" keys might need this same treatment. I've only really cared about the user roles and such since I had a lot of users trying to figure out why they can't post anymore. At least that's fixed.

Note: I don't know if this is clearly documented anywhere. If it is, I should be embarrased. However, I still want to voice a complaint that this isn't very straightforward. Maybe put a comment in wp-config.php?

Categories: WordPress
  1. vincent
    October 7th, 2008 at 10:58 | #1

    haha, duh mike. i could have told you that. next time ask, and save yourself the embarassment k lil buddy? 😉

    hi j!

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