Migration error with question2answer.rb

Hi there,

I am trying to use question2answer.rb importer script to migrate my site to the discourse platform. But I am facing the following error during the migration process.

How to fix it? :thinking: I am using the default docker container on a clean ubuntu 18.04.

importing users

**Traceback** (most recent call last):

9: from script/import_scripts/question2answer.rb:560:in `<main>'

8: from /var/www/discourse/script/import_scripts/base.rb:47:in `perform'

7: from script/import_scripts/question2answer.rb:71:in `execute'

6: from script/import_scripts/question2answer.rb:85:in `import_users'

5: from script/import_scripts/question2answer.rb:555:in `mysql_query'

4: from /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-mini-profiler-1.0.2/lib/patches/db/mysql2.rb:22:in `query'

3: from /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mysql2-0.5.2/lib/mysql2/client.rb:130:in `query'

2: from /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mysql2-0.5.2/lib/mysql2/client.rb:130:in `handle_interrupt'

1: from /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mysql2-0.5.2/lib/mysql2/client.rb:131:in `block in query'

/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mysql2-0.5.2/lib/mysql2/client.rb:131:in `_query': **Table 'primary_db.users' doesn't exist (** **Mysql2::Error** **)**

The users table that it’s looking for does not exist. Do you see a table called “users”? Do you have the right database?


I believe that I have the right database as I finished importing the database (on Discourse server) using

mysql -uroot -p -e 'CREATE DATABASE q2a' 

mysql -uroot -p q2a < q2a_dump.sql

I was able to back up my new database using

mysqldump -u username -p database_to_backup > backup_name.sql

and I downloaded it on my computer to verify that I have the proper database.

I have a table called qa_users

That’s the default. Did you change the db_prefix to “primary_dB” for some reason?

It was already included in the importer script as follows.


  DB_HOST ||= ENV['DB_HOST'] || "localhost"
  DB_PW ||= ENV['DB_PW']
  TIMEZONE ||= ENV['TIMEZONE'] || "America/Los_Angeles"
  MAIN_APP_DB_NAME = "primary_db"

So I didn’t change MAIN_APP_DB_NAME part as I am not familiar with that.

Did you set those environment variables? DB_NAME TABLE_PREFIX and so on?

I set all environment variables that I quoted above.

What did you set TABLE_PREFIX to?

export TABLE_PREFIX=“qa_”

Sorry. I’m in my logins and didn’t read the code carefully.

I’m pretty sure that I wrote that script, but I didn’t see that main all stuff down in the query; I’m sure I didn’t write that.

You’ll need to edit the script to have it use the database and prefix that you set in the environment variables.

What should I do about this one?

You’ll need to rewrite all of the dB queries.

I am sorry, Jay. I am not quite sure what you mean by that? Could you please give me some pointers here? I hope that you don’t mean by rewriting the importer script of question2answer.


Not the whole script, just the database queries, and really just the FROM part. If you have a budget I can fix it for you.


I don’t have much budget but I would like to import small data from my old forum.

What do you have in mind?

Send an email to support@literatecomputing.com.

If I can log in remotely to the machine where you’re running the import it’ll help, as I’ll be able to see whether it works without sending it to you, having you import, tell me what’s wrong, and trying again.


It seems the question2answer importer was written for a case where there is an additional set of tables in the database for another app that was integrated with it. That is what the MAIN_APP_DB_NAME refers to.

We have done an import for a standalone q2a site recently and we have a modified version of the script which does not depend on this extra database. @RGJ was going to clean it up and submit it back in the next few weeks.


[Here](https://gist.github.com/Communiteq (formerly DiscourseHosting)/769eff2014d5482f0ab776de03dc3349) is a gist of our modified importer so you don’t need to wait for me to clean it up, the code is already pretty ok though.

  • remove dependency on that other mysterious database which is probably something bespoke
  • import comments
  • import best answer

Aw nice, thanks for that :beers:

1 Like

In the recent attempt to migrate small data from my old forum resulted in the following error when I used [modified importer script](https://gist.github.com/Communiteq (formerly DiscourseHosting)/769eff2014d5482f0ab776de03dc3349) provided by @RGJ.

Loading existing groups...

Loading existing users...

Loading existing categories...

Loading existing posts...

Loading existing topics...

importing users

**Traceback** (most recent call last):

11: from script/import_scripts/question2answer.rb:601:in `&lt;main&gt;'

10: from /var/www/discourse/script/import_scripts/base.rb:47:in `perform'

9: from script/import_scripts/question2answer.rb:70:in `execute'

8: from script/import_scripts/question2answer.rb:89:in `import_users'

7: from /var/www/discourse/script/import_scripts/base.rb:881:in `batches'

6: from /var/www/discourse/script/import_scripts/base.rb:881:in `loop'

5: from /var/www/discourse/script/import_scripts/base.rb:882:in `block in batches'

4: from script/import_scripts/question2answer.rb:106:in `block in import_users'

3: from /var/www/discourse/script/import_scripts/base.rb:247:in `create_users'

2: from /var/www/discourse/script/import_scripts/base.rb:247:in `each'

1: from /var/www/discourse/script/import_scripts/base.rb:278:in `block in create_users'

/var/www/discourse/script/import_scripts/base.rb:866:in `print_status': **undefined method `to_f' for #&lt;Mysql2::Result:0x000056370b7c1f80&gt; (** **NoMethodError** **)**

**Did you mean? to_s**



I wonder what seems to be causing this error? :confused: