This article contains all migration steps and the database conversion script.

Installation of Wordpress

  1. Download Wordpress and unzip this file on your webserver. Detailed instructions for installing Wordpress can be found here: Installing WordPress, install Wordpress first in the /wordpress directory.
  2. First create an empty database for Wordpress, to achieve this phpMyAdmin can be used
  3. Open the URL to your Wordpress installation and do the initial configuration.
  4. After the Wordpress installation, remove the post “Hello world” permanently, also remove the “About” demo page.

Now we are ready for the next step

Converting the Drupal 6 tables into Wordpress 3 database tables

With the next steps, we are going to copy the Drupal database into the new Wordpress database

  1. Login into phpMyAdmin with enough rights
  2. Click on the old Drupal database in phpMyAdmin and select the tab “Operations“
  3. In the section “Copy database to:”, fill in the name of the Wordpress database
  4. Leave the selection on “Structure and data”
  5. Deselect “CREATE DATABASE before copying”, because we have already the database
  6. Select “Add DROP TABLE / DROP VIEW“
  7. Select “Add AUTO_INCREMENT value“
  8. Leave the other selections off
  9. Now press on the Go-button, to copy the database

In the next steps we are going to convert the Drupal database tables into the Wordpress tables

The database conversion script is not written by me, I found the base of the script here: http://blog.room34.com/archives/4530, I adapted it a little bit. The original converted directly from the Drupal database. I liked way of copying the database more, because I could remove some problem records from Drupal, without interfering the original database/site. In this way I had the time to complete the migration of Drupal to Wordpress, until everything was working correctly. I also filled in the posts&pages modified dates into the Wordpress database. In some other small adaptations like that.

# This assumes that WordPress and Drupal are copied in one databases, named 'wordpress'.
# The Drupal tables has the prefix ishk_
# The WordPress tables do not have a prefix
# If your database name or prefixes differ, adjust these accordingly.
# I had to comment out the VIDEO and IMAGE parts of the script. You can find it simply by
# searching VIDEO or IMAGE

# Empty previous content from WordPress database.
TRUNCATE TABLE wordpress.comments;
TRUNCATE TABLE wordpress.links;
TRUNCATE TABLE wordpress.postmeta;
TRUNCATE TABLE wordpress.posts;
TRUNCATE TABLE wordpress.term_relationships;
TRUNCATE TABLE wordpress.term_taxonomy;
TRUNCATE TABLE wordpress.terms;

# If you're not bringing over multiple Drupal authors, comment out these lines and the other
# author-related queries near the bottom of the script.
# This assumes you're keeping the default admin user (user_id = 1) created during installation.
DELETE FROM wordpress.users WHERE ID > 1;
DELETE FROM wordpress.usermeta WHERE user_id > 1;

# TAGS
# Using REPLACE prevents script from breaking if Drupal contains duplicate terms.
REPLACE INTO wordpress.terms
    (term_id, `name`, slug, term_group)
    SELECT DISTINCT
    d.tid, d.name, REPLACE(LOWER(d.name), ' ', '_'), 0
    FROM wordpress.ishk_term_data d
    INNER JOIN wordpress.ishk_term_hierarchy h
    USING(tid)
    INNER JOIN wordpress.ishk_term_node n
    USING(tid)
    WHERE (1
     # This helps eliminate spam tags from import; uncomment if necessary.
     # AND LENGTH(d.name) < 50
    )
;

INSERT INTO wordpress.term_taxonomy
    (term_id, taxonomy, description, parent)
    SELECT DISTINCT
    d.tid `term_id`,
    'post_tag' `taxonomy`,
    d.description `description`,
    h.parent `parent`
    FROM wordpress.ishk_term_data d
    INNER JOIN wordpress.ishk_term_hierarchy h
    USING(tid)
    INNER JOIN wordpress.ishk_term_node n
    USING(tid)
    WHERE (1
     # This helps eliminate spam tags from import; uncomment if necessary.
     # AND LENGTH(d.name) < 50
    )
;

# POSTS
# Keeps private posts hidden.
INSERT INTO wordpress.posts
    (id, post_author, post_date, post_date_gmt, post_content, post_title, post_excerpt, post_name, post_modified, post_modified_gmt, post_type, `post_status`)
    SELECT DISTINCT
    n.nid `id`,
    n.uid `post_author`,
    FROM_UNIXTIME(n.created) `post_date`,
    FROM_UNIXTIME(n.created-3600) `post_date_gmt`,
    r.body `post_content`,
    n.title `post_title`,
    r.teaser `post_excerpt`,
    IF(SUBSTR(a.dst, 11, 1) = '/', SUBSTR(a.dst, 12), a.dst) `post_name`,
    FROM_UNIXTIME(n.changed) `post_modified`,
    FROM_UNIXTIME(n.changed-3600) `post_modified_gmt`,
    n.type `post_type`,
    IF(n.status = 1, 'publish', 'private') `post_status`
    FROM wordpress.ishk_node n
    INNER JOIN wordpress.ishk_node_revisions r
    USING(vid)
    LEFT OUTER JOIN wordpress.ishk_url_alias a
    ON a.src = CONCAT('node/', n.nid)
    # Add more Drupal content types below if applicable.
    WHERE n.type IN ('post', 'page', 'blog')
;

# Fix post type; http://www.mikesmullin.com/development/migrate-convert-import-drupal-5-to-wordpress-27/#comment-17826
# Add more Drupal content types below if applicable.
UPDATE wordpress.posts
    SET post_type = 'post'
    WHERE post_type IN ('blog')
;

# Set all pages to "pending".
# If you're keeping the same page structure from Drupal, comment out this query
# and the new page INSERT at the end of this script.
UPDATE wordpress.posts SET post_status = 'pending' WHERE post_type = 'page';

# POST/TAG RELATIONSHIPS
INSERT INTO wordpress.term_relationships (object_id, term_taxonomy_id)
    SELECT DISTINCT nid, tid FROM wordpress.ishk_term_node
;

# Update tag counts.
UPDATE term_taxonomy tt
    SET `count` = (
    SELECT COUNT(tr.object_id)
    FROM term_relationships tr
    WHERE tr.term_taxonomy_id = tt.term_taxonomy_id
    )
;

# COMMENTS
# Keeps unapproved comments hidden.
# Incorporates change noted here: http://www.mikesmullin.com/development/migrate-convert-import-drupal-5-to-wordpress-27/#comment-32169
INSERT INTO wordpress.comments
    (comment_post_ID, comment_date, comment_date_gmt, comment_content, comment_parent, comment_author, comment_author_email, comment_author_url, comment_approved)
    SELECT DISTINCT
    nid, FROM_UNIXTIME(timestamp), FROM_UNIXTIME(timestamp-3600), comment, thread, name,
    mail, homepage, ((status + 1) % 2)
    FROM wordpress.ishk_comments
;

# Update comments count on posts table.
UPDATE wordpress.posts
    SET `comment_count` = (
    SELECT COUNT(`comment_post_id`)
    FROM wordpress.comments
    WHERE wordpress.posts.`id` = wordpress.comments.`comment_post_id`
    )
;

# Fix images in post content; uncomment if you're moving files from "files" to "wp-content/uploads".
# UPDATE wordpress.posts SET post_content = REPLACE(post_content, '"/files/', '"/wp-content/uploads/');

# Fix taxonomy; http://www.mikesmullin.com/development/migrate-convert-import-drupal-5-to-wordpress-27/#comment-27140
UPDATE IGNORE wordpress.term_relationships, wordpress.term_taxonomy
    SET wordpress.term_relationships.term_taxonomy_id = wordpress.term_taxonomy.term_taxonomy_id
    WHERE wordpress.term_relationships.term_taxonomy_id = wordpress.term_taxonomy.term_id
;

# OPTIONAL ADDITIONS — REMOVE ALL BELOW IF NOT APPLICABLE TO YOUR CONFIGURATION

# CATEGORIES
# These are NEW categories, not in wordpress.ishk_ Add as many sets as needed.
INSERT IGNORE INTO wordpress.terms (name, slug)
    VALUES
    ('First Category', 'first-category'),
    ('Second Category', 'second-category'),
    ('Third Category', 'third-category')
;

# Set category names to title case (in case term already exists [as a tag] in lowercase).
UPDATE wordpress.terms SET name = 'First Category' WHERE name = 'first category';
UPDATE wordpress.terms SET name = 'Second Category' WHERE name = 'second category';
UPDATE wordpress.terms SET name = 'Third Category' WHERE name = 'third category';

# Add categories to taxonomy.
INSERT INTO wordpress.term_taxonomy (term_id, taxonomy)
    VALUES
    ((SELECT term_id FROM terms WHERE slug = 'first-category'), 'category'),
    ((SELECT term_id FROM terms WHERE slug = 'second-category'), 'category'),
    ((SELECT term_id FROM terms WHERE slug = 'third-category'), 'category')
;

# Auto-assign posts to category.
# You'll need to work out your own logic to determine strings/terms to match.
# Repeat this block as needed for each category you're creating.
INSERT IGNORE INTO wordpress.term_relationships (object_id, term_taxonomy_id)
    SELECT DISTINCT p.ID AS object_id,
    (SELECT tt.term_taxonomy_id
    FROM wordpress.term_taxonomy tt
    INNER JOIN wordpress.terms t USING (term_id)
    WHERE t.slug = 'enter-category-slug-here'
    AND tt.taxonomy = 'category') AS term_taxonomy_id
    FROM wordpress.posts p
    WHERE p.post_content LIKE '%enter string to match here%'
    OR p.ID IN (
    SELECT tr.object_id
    FROM wordpress.term_taxonomy tt
    INNER JOIN wordpress.terms t USING (term_id)
    INNER JOIN wordpress.term_relationships tr USING (term_taxonomy_id)
    WHERE t.slug IN ('enter','terms','to','match','here')
    AND tt.taxonomy = 'post_tag'
    )
;

# Update category counts.
UPDATE term_taxonomy tt
    SET `count` = (
    SELECT COUNT(tr.object_id)
    FROM term_relationships tr
    WHERE tr.term_taxonomy_id = tt.term_taxonomy_id
    )
;

# AUTHORS
INSERT IGNORE INTO wordpress.users
    (ID, user_login, user_pass, user_nicename, user_email,
    user_registered, user_activation_key, user_status, display_name)
    SELECT DISTINCT
    u.uid, u.mail, NULL, u.name, u.mail,
    FROM_UNIXTIME(created), '', 0, u.name
    FROM wordpress.ishk_users u
    INNER JOIN wordpress.ishk_users_roles r
    USING (uid)
    WHERE (1
    # Uncomment and enter any email addresses you want to exclude below.
    # AND u.mail NOT IN ('test@example.com')
    )
;

# Assign author permissions.
# Sets all authors to "author" by default; next section can selectively promote individual authors
INSERT IGNORE INTO wordpress.usermeta (user_id, meta_key, meta_value)
    SELECT DISTINCT
    u.uid, 'capabilities', 'a:1:{s:6:"author";s:1:"1";}'
    FROM wordpress.ishk_users u
    INNER JOIN wordpress.ishk_users_roles r
    USING (uid)
    WHERE (1
    # Uncomment and enter any email addresses you want to exclude below.
    # AND u.mail NOT IN ('test@example.com')
    )
;
INSERT IGNORE INTO wordpress.usermeta (user_id, meta_key, meta_value)
    SELECT DISTINCT
    u.uid, 'user_level', '2'
    FROM wordpress.ishk_users u
    INNER JOIN wordpress.ishk_users_roles r
    USING (uid)
    WHERE (1
    # Uncomment and enter any email addresses you want to exclude below.
    # AND u.mail NOT IN ('test@example.com')
    )
;

# Change permissions for admins.
# Add any specific user IDs to IN list to make them administrators.
# User ID values are carried over from wordpress.ishk_
UPDATE wordpress.usermeta
    SET meta_value = 'a:1:{s:13:"administrator";s:1:"1";}'
    WHERE user_id IN (1) AND meta_key = 'capabilities'
;
UPDATE wordpress.usermeta
    SET meta_value = '10'
    WHERE user_id IN (1) AND meta_key = 'user_level'
;

# Reassign post authorship.
UPDATE wordpress.posts
    SET post_author = NULL
    WHERE post_author NOT IN (SELECT DISTINCT ID FROM wordpress.users)
;

# VIDEO – READ BELOW AND COMMENT OUT IF NOT APPLICABLE TO YOUR SITE
# If your Drupal site uses the content_field_video table to store links to YouTube videos,
# this query will insert the video URLs at the end of all relevant posts.
# WordPress will automatically convert the video URLs to YouTube embed code.;
UPDATE IGNORE wordpress.posts p, wordpress.ishk_content_field_video v
    SET p.post_content = CONCAT_WS('\n',post_content,v.field_video_embed)
    WHERE p.ID = v.nid
;

# IMAGES – READ BELOW AND COMMENT OUT IF NOT APPLICABLE TO YOUR SITE
# If your Drupal site uses the content_field_image table to store images associated with posts,
# but not actually referenced in the content of the posts themselves, this query
# will insert the images at the top of the post.
# HTML/CSS NOTE: The code applies a "drupal_image" class to the image and places it inside a <div>
# with the "drupal_image_wrapper" class. Add CSS to your WordPress theme as appropriate to
# handle styling of these elements. The <img> tag as written assumes you'll be copying the
# Drupal "files" directory into the root level of WordPress, NOT placing it inside the
# "wp-content/uploads" directory. It also relies on a properly formatted <base href="" /> tag.
# Make changes as necessary before running this script!
UPDATE IGNORE qb102200_arjans_logboek.posts p, qb102200_arjans_logboek.ishk_content_field_image i, qb102200_arjans_logboek.ishk_files f
   SET p.post_content =
   CONCAT(
       CONCAT(
           '<div class="drupal_image_wrapper"><img src="files/',
           f.filename,
           '" class="drupal_image" /></div>'
       ),
       p.post_content
    )
    WHERE p.ID = i.nid
    AND i.field_image_fid = f.fid
    AND (
    f.filename LIKE '%.jpg'
    OR f.filename LIKE '%.jpeg'
    OR f.filename LIKE '%.png'
    OR f.filename LIKE '%.gif'
    )
;

# Fix post_name to remove paths.
# If applicable; Drupal allows paths (i.e. slashes) in the dst field, but this breaks
# WordPress URLs. If you have mod_rewrite turned on, stripping out the portion before
# the final slash will allow old site links to work properly, even if the path before
# the slash is different!
UPDATE wordpress.posts
    SET post_name =
    REVERSE(SUBSTRING(REVERSE(post_name),1,LOCATE('/',REVERSE(post_name))-1))
;

# Miscellaneous clean-up.
# There may be some extraneous blank spaces in your Drupal posts; use these queries
# or other similar ones to strip out the undesirable tags.
UPDATE wordpress.posts
    SET post_content = REPLACE(post_content,'

','')
;
UPDATE wordpress.posts
    SET post_content = REPLACE(post_content,'

','')
;

# NEW PAGES – READ BELOW AND COMMENT OUT IF NOT APPLICABLE TO YOUR SITE
# MUST COME LAST IN THE SCRIPT AFTER ALL OTHER QUERIES!
# If your site will contain new pages, you can set up the basic structure for them here.
# Once the import is complete, go into the WordPress admin and copy content from the Drupal
# pages (which are set to "pending" in a query above) into the appropriate new pages.
INSERT INTO wordpress.posts
    (`post_author`, `post_date`, `post_date_gmt`, `post_content`, `post_title`,
    `post_excerpt`, `post_status`, `comment_status`, `ping_status`, `post_password`,
    `post_name`, `to_ping`, `pinged`, `post_modified`, `post_modified_gmt`,
    `post_content_filtered`, `post_parent`, `guid`, `menu_order`, `post_type`,
    `post_mime_type`, `comment_count`)
    VALUES
    (1, NOW(), NOW(), 'Page content goes here, or leave this value empty.', 'Page Title',
    '', 'publish', 'closed', 'closed', '',
    'slug-goes-here', '', '', NOW(), NOW(),
    '', 0, 'http://full.url.to.page.goes.here', 1, 'page', '', 0)
;

To run the conversion script, you need to perform the following steps:

  1. Login into phpMyAdmin with enough rights
  2. Click on the new Wordpress database
  3. Click on the tab “SQL“
  4. Select the above script and copy it (Ctrl-C)
  5. Open your favorite editor and paste (Ctrl-V) the script in the editor
  6. Comment out VIDEO and IMAGE if applicable
  7. Select the complete script in the editor (Ctrl-A) and past it in the “SQL” tab
  8. Press the Go-button to start the conversion
  9. It is possible to re-run the script more than once in case of problems.

I had the following problems with the script:

  • 4 of the 200 posts had a key error message while running the script. I simply removed these records, it is possible to re-run the script over and over until it is successfully finished.
  • I copied the 4 posts by hand from my old Drupal 6 website into the new Wordpress 3.01 website
  • I commented out the VIDEO and IMAGE part
  • The script does not support CCK