Redmine

Hello,

I just wrote a PHP script to do exactly that. You may find there: https://github.com/PowerKiKi/redmine-tools
Be sure to test it out before using on production database. You'll find basic instructions in migrator.php

I think that this tool might interest you : https://github.com/dctremblay/Project-Rescue

With that tool, you can migrate individual project from Redmine 2.x / 3.2 from an instance to another with all their dependencies (issues, users, parent projects, children projects, news, documents, attachments, custom fields etc..)

It is a script made in Python3 so make sure that it is already installed.

Looks just like the tool I want, however I need to migrate from MySQL -> MSSQL and are not skilled enough to modify the orm.py file to make that connection work. Hopefully it will be added in the near future.

Current Redmine could filter the issues and send them to the REST API of the external server

1. Create a proper rake task: /usr/share/redmine/lib/tasks/migrate_to_redmine.rake
   

   namespace :redmine do
     desc 'Migrate to another Redmine'
     task :migrate_to_redmine => :environment do
   
       query = IssueQuery.new(:project => Project.find(123), :name => 'CurrentProject')
       query.add_filter('status_id', '*', [''])
       query.add_filter('parent_id', '!*', [''])
   #    query.add_filter("issue_id", '><', ['32500', '42100'])
       issues = Issue.joins(:status, :tracker, :project, :priority).where(query.statement).to_a
   
       issues.sort.each do |issue|
         migrate_issue issue.id, nil
       end
   
     end
   
     def migrate_issue id, parent_id
       issue = Issue.find(id)
   
       created = {POST issue to the REST API of the external server}
   
       if created
         for child in issue.children
           migrate_issue child.id, created.id
         end
       end
     end
   
   end
   

2. cd /usr/share/redmine/
3. rake redmine:migrate_to_redmine