要約

When a CSV import is performed in Jira, we usually lose Parent-child relationships between imported issues, but the links can be maintained.

Confirm proper formatting in the CSV file

Issue relationships are usually lost because of issue order in the CSV file and/or improper mapping of the parent and child during the import process. 

First, make sure the exported CSV file contains at least the following columns for the parent-child mapping:

 Issue type, Issue key, Issue ID, Summary, Parent

Next, confirm the file has all issues listed in order of their hierarchy. 

That is, the topmost rows of the CSV must list all the Highest hierarchy issue types, with subsequent rows including the Standard issue types, and finally the Sub-task types. 

Map issue IDs using the Parent field in the CSV file

For the parent→child relationship to work, copy the Issue ID of the parent issue and paste it in the Parent column of the the Child issue.

After making the above changes, the Issue Type mappings should look as per the below sample screenshot.

issue type,issue key,status,summary,issue id,parent
Theme,test-123,To Do,Example theme summary,1,
initiative,test-124,To Do,Example initiative summary,2,1
Epic,test-125,To Do,Epic with parent and no child story but 1 sub-task and parent Inititive,3,2
Epic,test-126,To Do,This is an epic with 1 story and 1 bug as child issues mapped,4,
Story,test-127,To Do,Example story 1 Summary no child issue mapped,5,
Story,test-128,To Do,"Example story with 1 child sub-task mapped, and a parent epic is mapped",6,4
Bug,test-129,To Do,bug with 1 child sub-task ,106589,4
sub-task,test-130,To Do,subtask 1,7,6
sub-task,test-131,To Do,subtask 2,8,106589
sub-task,test-132,To Do,Subtask 3,9,3

The CSV file is now ready for import. 

Import the CSV file to Jira

1. Select Settings (cog icon) > System
2. Navigate to External system import under the "Import and export" heading
3. Select Switch to the old experience
4. Select CSV
5. Select "Choose File" and navigate to the file via your machine's file explorer 
6. Once uploaded, select Next
7. Select the destination project where you want the issues to be imported from the CSV file
   1. Unless you made custom changes to any additional date and time fields or email address fields, leave formatting as default 
8. Map the CSV fields with the corresponding Jira fields as below:
   1. Issue id → Issue id
   2. Issue key → Issue Key
   3. issue type → Issue Type
   4. parent → Parent
   5. status → Status
   6. summary → Summary
   7. You can also reference below sample screenshot
      
9. Select Next
10. Verify status values map to your desired statuses in Jira
    
    1. For example, that the "To Do" status maps to the relevant status in your desired project
11. Select Begin import

During CSV import, you can also include any other custom fields you wish in the CSV file and import them along with the correct parent-child mapping.

Demonstration of post-import results

If we imported our example issues as listed above, the end result would look like the below screenshot.