How to fetch isolation source and sequence for subsequence in C3.ai COVID-19 Data Lake? - c3ai-datalake

Question

I'm running API calls to the C3.ai COVID-19 Data Lake in Postman. I'm using Fetch on the Subsequence type, and want to get the isolationSource for the BiologicalAsset that is related to the Subsequence. But I can't figure out how to access this field properly. I'm running POST on https://api.c3.ai/covid/api/1/subsequence/fetch. Here's the request body:
{
spec: {
include: "startIndex, endIndex, sequence, sequence.isolationSource",
limit: 10
}
}
But then each object in the resulting XML looks like this:
<k>0</k>
<v>
<startIndex>1</startIndex>
<endIndex>182</endIndex>
<id>LC522350_1-182</id>
<meta>
<fetchInclude>[startIndex,endIndex,sequence,id,version]</fetchInclude>
<fetchType>Subsequence</fetchType>
</meta>
<version>1</version>
</v>
This doesn't properly show the sequence or isolation source. How do I find these?

Answer 1

Based on the API docs, you need to use "parent" to refer to the Sequence associated with a Subsequence, and then use that parent's parent to refer to a BiologicalAsset. That would make your request:
{
spec: {
include: "startIndex, endIndex, parent.sequence, parent.parent.isolationSource",
limit: 10
}
}
I just tried this and noticed that some Subsequences don't have isolation sources. If you want to only include results that have an isolation source, you would add filter: "exists(parent.parent.isolationSource)" to your spec.