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Guide to upgrading from existing WordPress installation (3 posts)

  1. qoncept
    Posted 16 years ago #

    I've been working on upgrading my old existing WordPress installation to WPMU. I've documented the experience into what should be a pretty accurate guide to doing so in hopes that it may be of some use to someone else.

    Before I apply these changes to my live site and claim this is accurate, I was hoping I could get someone to review my guide and tell provide any input. One point I'd like some help with is the non-breaking space issue (see step 5), in which the dump is replacing non-breaking spaces with an odd ascii character. Thanks!

    Edit: Turns out I can't login to the new site either. I'm not 100% certain whether this has anything to do with the fact that I'm running the test on a different URL.

    And here it is:
    Upgrade WordPress to Wordpress MU

    This is a quick draft for what I've done to install a new WPMU installation
    TO THE SAME location as my old existing WP installation. eg, my old blog,
    which was at will still be there and users shouldn't
    see any change. New blogs will be located at *
    (,, etc).

    This guide assumes you have a fairly good knowledge of SQL. I'm using
    phpmyadmin to make everything a bit easier. I'm writing it as I do a test
    upgrade of my blog, so its a guide more for me than anyone else, but I
    thought some other people might find it useful so I've cleaned it up a bit.
    This document is provided without any implied guarantees. If you have
    questions, contact Jared on

    1) Create fresh WPMU install following its install instructions

    2) Contact host to set up wildcard dns (*

    3) Upload theme to new MU installation (if applicable)

    4) In phpmyadmin, export the database from existing WP installation. Make
    sure you have following options checked:


    Save the dump as a file without compression.

    5) Find and replace table names in the database dump:

    Existing line: INSERT INTO 'wp_
    Replace with: INSERT INTO 'wp_1_

    Existing line: DROP TABLE IF EXISTS `wp_
    Replace with: DROP TABLE IF EXISTS `wp_1_

    Existing line: CREATE TABLE IF NOT EXISTS `wp_
    Replace with: CREATE TABLE IF NOT EXISTS `wp_1_

    For whatever reason, non-breaking spaces were screwing up in my exports:
    Existing text: Â
    Replace with:  

    6) Change common WPMU table names back for shared tables, making sure to
    change the table names in the drop, create and insert blocks. These tables should
    appear at the end of your dump:

    7) Run SQL from original WP database dump

    8) Double check everything you can think of -- you should be good to go

  2. peacearena
    Posted 16 years ago #

    I'm moving what was an old version of WP to WPMU. I first upgraded the existing WP install to the latest version. The export/import in the toolbar didn't work, so I'm working in phpmyadmin.

    I got all the post, link and category tables moved (to blog 2) thanks to another post here on the forums, now I need to move users. But I notice that there's a different default charset now. Is this an issue? If I need to change, it there anything more to it than just replacing "latin1" with utf8" in the table dump?

    Thanks in advance for any assistance.

  3. peacearena
    Posted 16 years ago #

    Never mind, I just did the INSERT parts via SQL, after adding the additional 2 fields (spam and deleted). Then I went to the blog's user control page and added each one, with the form at the bottom, to that blog manually (only had 30).

About this Topic

  • Started 16 years ago by qoncept
  • Latest reply from peacearena