Issue key mapping during CSV import

[Gopa Kumar]

I want to update comments to an existing issue already imported. How can I map the issue key. I do not seem to find issue key as part of mapping the fields from CSV to Jira

[Cesar Covarrubias]

I just did this with a manually migration from Mantis Bug Tracker to JIRA. It is a bit of a convuluted process.

1. I imported the Mantis key as a custom field in JIRA
2. I pulled an XLS report for the project. That gave me the JIRA - Mantis key relationship.
3. Then using this keymap, I substituted the original key with the new JIRA key using Excel (VLOOKUP function).

Hope this helps.