Feature #3125

Merging 2 different Redmine Installations

Added by Ashwin Muni over 13 years ago. Updated almost 5 years ago.

Status:NewStart date:2009-04-06
Priority:NormalDue date:
Assignee:-% Done:


Target version:-


I have redmine installed in 2 systems A and B.

Redmine Specs
Version : 0.8.0

I want both the redmine version to be merged to one now. Does redmine has any such feature where i can merge the database from other redmine installation or location.

Redmine A                       Redmine B
Want both to merge

So that the results would be

Redmine ( A + B )  = Redmine (Final)

Please provide me the soln.


migrate.txt Magnifier - General migration.. (6.47 KB) Kiall Mac Innes, 2009-04-29 15:08

migrate2 - Merging 2 user accounts after the migration... (1.18 KB) Kiall Mac Innes, 2009-04-29 15:08


#1 Updated by Jean-Philippe Lang over 13 years ago

Sorry, there's no such feature.

#2 Updated by Kiall Mac Innes over 13 years ago

I recently merged a trac and redmine database in a way that may work for you..

Basically - i used the trac importer to create a redmine DB from the trac one. then the existing redmine DB was merged into this new one..

See the attached SQL queries as a base for what your going to need to to on the "to be deleted db" - after all these queries, you can export the data from the old db, and just insert them into the new one..

Aka - Pick one of your existing installs to the the final one and merge the other DB into it ...

The queries i used DO NOT COVER all circumstances - we has been using a limited set of trac features and a limited set of redmine features... You'll need to add more queries...!

#3 Updated by Kiall Mac Innes over 13 years ago

Note... all those numbers in the queries represent the MAX from the corresponding table from the DB u pick as the "final one" ...

Eg all the 380's in the "//User IDs" section are because on the "final db" "SELECT MAX AS max FROM users" returns 380...

Good luck - its not easy.

#4 Updated by Zarooba Rozruba over 13 years ago

A warnings : if you have anywhere references to ticket numbers, in text as opposed to db schema based link, then it will start pointing to a wrong location.

For example:

redmine a : commit comment : closes # 123
redmine b : commit comment : closes # 123

When merged, commit comments will stay intact, while one of them will have their tickets renumbered. This will cause some confusion.

If I can bring up my own related need : see ticket #3087

#5 Updated by Chris Born over 13 years ago

This very closely relates to a forum post I made just yesterday about moving a single project from one Redmine install to another. I began looking at the DB to see what it would take, then just ran across this. I was thinking of a possible solution for this being a project export/import feature. This would be really helpful, either project based merger or full Redmine install.

#6 Updated by Eric Davis almost 13 years ago

  • Priority changed from Urgent to Normal

I just recently completed a plugin that will let you merge two Redmine database together. It worked for my customer, but I need to add some documentation before I can create a release of it. If you're interested, it's located at http://github.com/edavis10/redmine_merge_redmine

#7 Updated by Christian Rodriguez almost 9 years ago

I updated Eric Davis plugin to be compatible with current redmine version. Source code (until pull request is accepted) is located at https://github.com/chrodriguez/redmine_merge_redmine

#8 Updated by Baris Demiray about 8 years ago

Hi all,

First of all, thanks to those who contributed the scripts!

I was just using Christian's version and I had problems with clashing project indexes, which was expected, so I updated project_id values in all the tables so that they would not clash, but then now I'm having the error below,

PG::UniqueViolation: ERROR:  duplicate key value violates unique constraint "projects_trackers_unique" 
DETAIL:  Key (project_id, tracker_id)=(4, 1) already exists.
: INSERT INTO "projects_trackers" ("project_id", "tracker_id") VALUES (4, 1)

Tasks: TOP => redmine:merge_redmine
(See full trace by running task with --trace)

Apparently, tracker_id field is now unique in recent versions of Redmine, which is not the case at all in older database (as there are tracker_ids 1 to 4 for every single project_id). Am I missing something?

Some information,
Source Redmine: v1.2.0 (SQLite) # I converted SQLite to PostgreSQL as described in 2.2 of http://vault-tec.info/post/68670739052/installing-migrating-upgrading-redmine-with-ldap-on.
Destination Redmine: v2.5.2 (PostgreSQL)

Thanks in advance,


#9 Updated by Arthur Andersen over 7 years ago

For anyone who's trying to accomplish the same thing.
I updated the merge plugin to work with Redmine 3.0.

With this I was able to merge 2.3 and 2.5 into an up-to-date 3.0 database.
Simply migrate each redmine database to the latest version and run the plugins merge task.


Thank you for all the work that you put into this!

#10 Updated by David Chen almost 5 years ago

@Mr Arthur Andersen

Now that the version to upgraded to version 3.4.4, my question is whether or not the scripts still can work for it? Your reply will be highly appreciatedly.

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