Just completed, for the most part (still in test bed, but the “hard parts” are basically done and the migration works fine), migrating a 15 year old vb3 forum, which was originally (believe-it-or-not) a vb2 forum from 2000.
This forum has been around for around 20 years (with unimaginable custom PHP code, tables, plugins, etc), and Discourse is the only forum software, in my view, “worthy” of a migration project, which I started around a week ago, going from feasibility to completion (basically).
First of all, I want to thank the entire Discourse team for such a remarkable “work-of-art” modern forum. Discourse is truly remarkable, in my view (and I am sure many others).
Second, I would like to thank the team who coded the original vbulletin.rb migration script. This script was about 95% OK. and I modified that script to get it to work properly for vb3. For example, vb3 does not have a filedata table like vb4 (related to attachments); so I modified vbulletin.rb to get it to work. Also, there were issues importing child vb3 forums as categories, but I modified the code to import all forums as top level categories and then wrote some postgres psql to create new parent-child categories relationships (or manually configured). There were other “gotchas” (a story for another day) but those goblins made it fun and challenging, but not insurmountable.
Third, I would like to thank Sam and his code lithium.rb where I used his import_likes routine as the basis for my vb3 thank you (from a legacy plugin, not part of vB OOTB) to discourse likes. I made minor changes to the import_likes routine and after a few hours of debugging, got it to work.
As you can see from this 2018 post, migrated today:
I thought it was important for users that their vb thanks migrated to discourse likes and so here is the code I used to migrate the likes for other lost vb3 forum souls:
First of all I created a vb3 mysql table called user_actions and wrote a PHP script to fill it from the legacy vb post_thanks table, like this (not polished, but working):
ubuntu:/var/www/includes/cron# cat thanks_to_discourse.php
<?php
/**************************************************
+-----------+------------+-----------+-----------+
| thanker | unixtime | id | thanked |
+-----------+------------+-----------+-----------+
| 1 | 1584149592 | 303045211 | 302093876 |
| 302153369 | 1584136706 | 303045214 | 302116191 |
| 302108573 | 1584128526 | 303045211 | 302093876 |
| 302153369 | 1584126659 | 303042175 | 302116191 |
| 302153369 | 1584126400 | 303045174 | 302116191 |
| 302153369 | 1584117711 | 303045184 | 1 |
| 37898 | 1584108187 | 303045175 | 1 |
| 302181242 | 1584106664 | 303045201 | 302122047 |
| 302181242 | 1584104642 | 303045074 | 302052697 |
| 302025710 | 1584103722 | 303045184 | 1 |
+-----------+------------+-----------+-----------+
**************************************************/
$query = 'SELECT p.threadid AS threadid,t.userid AS thanker,t.date AS unixtime,t.postid AS postid,p.userid AS thanked from post_thanks as t LEFT JOIN post p ON p.postid = t.postid';
$allthanks = $vbulletin->db->query_read($query);
/****************************************
mysql> describe user_actions;
+-----------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+------------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| action_type | int(11) unsigned | NO | | NULL | |
| user_id | int(11) unsigned | NO | | NULL | |
| target_topic_id | int(11) unsigned | YES | | NULL | |
| target_post_id | varchar(16) | YES | | NULL | |
| target_user_id | int(11) unsigned | YES | | NULL | |
| acting_user_id | int(11) unsigned | YES | | NULL | |
| created_at | timestamp | YES | | NULL | |
| updated_at | timestamp | YES | | NULL | |
+-----------------+------------------+------+-----+---------+----------------+
9 rows in set (0.00 sec)
INSERT INTO table_name (column1, column2, column3, ...)
VALUES (value1, value2, value3, ...);
*************************************/
$action_code = 2; // discourse like action == 2
$target_user_id = "";
while ($action = $vbulletin->db->fetch_array($allthanks)) {
#code to deal with how discourse identifies the first post in a topic in the post_custom_fields table
$query = 'SELECT firstpostid FROM thread WHERE threadid =' . $action['threadid'] . ' LIMIT 1';
$threadinfo = $vbulletin->db->query_first($query);
if ($threadinfo['firstpostid'] == $action['postid']) {
$action['postid'] = 'thread-' . $action['threadid'];
}
$update = 'INSERT INTO user_actions (action_type, user_id, target_topic_id, target_post_id, target_user_id,acting_user_id, created_at, updated_at)' .
' VALUES (' . $action_code . ',' .
'"' . $action['thanked'] . '",' .
'"' . $action['threadid'] . '",' .
'"' . $action['postid'] . '",' .
'"' . $target_user_id . '",' .
'"' . $action['thanker'] . '",' .
'FROM_UNIXTIME(' . $action['unixtime'] . '),' .
'FROM_UNIXTIME(' . $action['unixtime'] . '))';
$doit = $vbulletin->db->query_write($update);
}
So, this mysql user_actions table is included with the migration dump.
Here is the modified import_likes routine I used to complete the migration on the discourse side:
def import_likes
puts "\nimporting likes..."
# created mysql user_actions table in vb3 using PHP script and included that table with migration dump
sql = "select acting_user_id as user_id, target_post_id as post_id, created_at from user_actions"
results = mysql_query(sql)
puts "length() method form : #{results.count}\n\n"
puts "skip loading unique id map"
existing_map = {}
PostCustomField.where(name: 'import_id').pluck(:post_id, :value).each do |post_id, import_id|
existing_map[import_id] = post_id
#puts "postcustomfield existing_map post_id: #{post_id} import_id #{import_id}\n"
end
puts "loading data into temp table"
#manually created the temp like_data table so I could check the table after session ends
#DB.exec("create temp table like_data(user_id integer, post_id integer, created_at timestamp without time zone)")
puts "like_data temp table created"
PostAction.transaction do
results.each do |result|
result["user_id"] = user_id_from_imported_user_id(result["user_id"].to_s)
result["post_id"] = existing_map[result["post_id"].to_s]
next unless result["user_id"] && result["post_id"]
puts "insert like table user_id: #{result["user_id"]} post_id #{result["post_id"]}\n"
DB.exec("INSERT INTO like_data VALUES (:user_id,:post_id,:created_at)",
user_id: result["user_id"],
post_id: result["post_id"],
created_at: result["created_at"]
)
end
end
puts "creating missing post actions"
DB.exec <<~SQL
INSERT INTO post_actions (post_id, user_id, post_action_type_id, created_at, updated_at)
SELECT l.post_id, l.user_id, 2, l.created_at, l.created_at FROM like_data l
LEFT JOIN post_actions a ON a.post_id = l.post_id AND l.user_id = a.user_id AND a.post_action_type_id = 2
WHERE a.id IS NULL
SQL
puts "creating missing user actions"
DB.exec <<~SQL
INSERT INTO user_actions (user_id, action_type, target_topic_id, target_post_id, acting_user_id, created_at, updated_at)
SELECT pa.user_id, 1, p.topic_id, p.id, pa.user_id, pa.created_at, pa.created_at
FROM post_actions pa
JOIN posts p ON p.id = pa.post_id
LEFT JOIN user_actions ua ON action_type = 1 AND ua.target_post_id = pa.post_id AND ua.user_id = pa.user_id
WHERE ua.id IS NULL AND pa.post_action_type_id = 2
SQL
# reverse action
DB.exec <<~SQL
INSERT INTO user_actions (user_id, action_type, target_topic_id, target_post_id, acting_user_id, created_at, updated_at)
SELECT p.user_id, 2, p.topic_id, p.id, pa.user_id, pa.created_at, pa.created_at
FROM post_actions pa
JOIN posts p ON p.id = pa.post_id
LEFT JOIN user_actions ua ON action_type = 2 AND ua.target_post_id = pa.post_id AND
ua.acting_user_id = pa.user_id AND ua.user_id = p.user_id
WHERE ua.id IS NULL AND pa.post_action_type_id = 2
SQL
puts "updating like counts on posts"
DB.exec <<~SQL
UPDATE posts SET like_count = coalesce(cnt,0)
FROM (
SELECT post_id, count(*) cnt
FROM post_actions
WHERE post_action_type_id = 2 AND deleted_at IS NULL
GROUP BY post_id
) x
WHERE posts.like_count <> x.cnt AND posts.id = x.post_id
SQL
puts "updating like counts on topics"
DB.exec <<-SQL
UPDATE topics SET like_count = coalesce(cnt,0)
FROM (
SELECT topic_id, sum(like_count) cnt
FROM posts
WHERE deleted_at IS NULL
GROUP BY topic_id
) x
WHERE topics.like_count <> x.cnt AND topics.id = x.topic_id
SQL
end
end
I hope this post helps others who might migrate from vB3 to discourse, since many people used the legacy vb3 “thank you” plugin for many years.
Also, I spent a lot of time in the discourse database and inside a lot of discourse ruby scripts, so this migration was tricky (not for the faint of heart to be sure), but certainly doable.
Actually, I enjoyed doing it. This was the first time in ruby for me; so it was fun to start to learn ruby and as a long time mysql person, the postgres part was mostly routine.
We will be going live soon… Thank You Discourse Team!!!
