How do you combine/merge multiple custom fields into one field?

Ben_f4x8nh

When we initially switched to Jira, we imported issues from bugzilla.  As part of this (I wasn't involved), it created a custom field per project, each one labelled the same as External issue ID.  So now, when ever we are doing anything with field configurations, we have 10's of these seemingly identical fields in the list.  Is there a way to collapse these fields into one field – I presume that there will never be a conflict in the actual database, as each one is only populated at all in a single project.

 More generally, the question is can we merge the contents of multiple custom fields into one field.

Boris Georgiev [Appfire]

I don't think that merging the values can be achieved without modifying the database directly OR using a script (groovy for example) and since I see you added cloud to the tags of the question I don't think you can do this.

I think the only option would be to :

1. export your cloud instance and import it to a server installation
2. Modify the data - merging the fields via SQL or Groovy Script
3. Create a backup of this temporary server instance and import back to cloud

I would recommend doing the field merge via the JIRA API and not the database directly and the way it could work is:

1. Create new field which have a context for each project or 1 global context and name it for example NEW External Issue ID
2. Write a plugin or groovy script that copies the value from External issue ID to NEW EXTERNAL ISSUE ID
3. Delete the all the old fields