Why do I need a Summary Mapping when I'm already providing an Issue Key Mapping?

[Tom Bridges]

When I'm performing an Import from a CSV file, why do I need a Summary Mapping when I'm already providing an Issue Key Mapping?

The data I'm trying to map to the current issues does not have the Summary field so this is impossible to import the data.

[Nic Brough -Adaptavist-]

Summary is the only field in JIRA that you absolutely have to fill in when doing an import from CSV (and the rest of the time actually).  It can never be left blank.

[Nic Brough -Adaptavist-]

No, that's not what I said.  Summary is mandatory, but it's not a key.

[Tom Bridges]

But why? I'm supplying the Issue Key, so the importer should know which issue to put the Comment Body against. It makes no sense to require the summary too. The Comments I'm trying to import and stored in a table that links via the Issue Key, so the Summary isn't available.

[Nic Brough -Adaptavist-]

Ah, you don't need the summary if all the updates have a key so that it's clearly an update.