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Elasticsearch.Net and NEST: the .NET clients [5.x] » Aggregations » Child Aggregation Mapping
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Child Aggregation Mappingedit

To use the Children Aggregation, you have to make sure a _parent mapping is in place.

Here we create the project index with two mapped types, Project and CommitActivity and add a _parent mapping to CommitActivity, specifying the Project type as the parent

var createProjectIndex = TestClient.GetClient().CreateIndex(typeof(Project), c => c
    .Mappings(map => map
        .Map<Project>(tm => tm.AutoMap())
        .Map<CommitActivity>(tm => tm
            .Parent<Project>() 
        )
    )
);

Set the parent of CommitActivity to the Project type

«  Writing Aggregations     Children Aggregation Usage  »