Elasticsearch Dynamic Aggregations with NEST

Question

Hi there I have the following mapping for product in elastic I am trying to create aggregations from the Name / Value data in product specifications I think what i need to achieve is with Nested aggregations but im struggling with the implementation

  "mappings": {
"product": {
  "properties": {
    "productSpecification": {
      "properties": {
        "productSpecificationId": {
          "type": "long"
        },
        "specificationId": {
          "type": "long"
        },
        "productId": {
          "type": "long"
        },
        "name": {
          "fielddata": true,
          "type": "text"
        },
        "value": {
          "fielddata": true,
          "type": "text"
        }
      }
    },
        "name": {
          "type": "text",
          "fields": {
            "keyword": {
              "ignore_above": 256,
              "type": "keyword"
            }
          }
        },
        "value": {
          "type": "text",
          "fields": {
            "keyword": {
              "ignore_above": 256,
              "type": "keyword"
            }
          }
        }
      }
    },
    "description": {
      "type": "text",
      "fields": {
        "keyword": {
          "ignore_above": 256,
          "type": "keyword"
        }
      }
    },
    "reviewRatingCount": {
      "type": "integer"
    },
    "productId": {
      "type": "integer"
    },
    "url": {
      "type": "text",
      "fields": {
        "keyword": {
          "ignore_above": 256,
          "type": "keyword"
        }
      }
    },
    "dispatchTimeInDays": {
      "type": "integer"
    },
    "productCode": {
      "type": "text",
      "fields": {
        "keyword": {
          "ignore_above": 256,
          "type": "keyword"
        }
      }
    },
    "name": {
      "type": "text",
      "fields": {
        "keyword": {
          "ignore_above": 256,
          "type": "keyword"
        }
      }
    },

I have now changed the code below and I am getting some success

.Aggregations(a => a
            .Terms("level1",t => t
                .Field(f=> f.ProductSpecification.First().Name)
                .Aggregations(snd => snd
                    .Terms("level2", f2 => f2.Field(f3 => f3.ProductSpecification.First().Value))
                    )))

by using this code i am now returning the Name values

 var myagg = response.Aggs.Terms("level1");
            if(response.Aggregations != null)
            {
                rtxAggs.Clear();

                rtxAggs.AppendText(Environment.NewLine);
                foreach(var bucket in myagg.Buckets)
                {
                    rtxAggs.AppendText(bucket.Key);

                }


            }

What i cant figure out is how to then get the sub aggregation values

Answer 1

Right after much experimenting and editing Ive managed to get to the bottom of this

First up I Modified productSpecification back to nested and then used the following in the aggregation

.Aggregations(a => a
            .Nested("specifications", n => n
                .Path(p => p.ProductSpecification)
                .Aggregations(aa => aa.Terms("groups", sp => sp.Field(p => p.ProductSpecification.Suffix("name"))
                    .Aggregations(aaa => aaa
                        .Terms("attribute", tt => tt.Field(ff => ff.ProductSpecification.Suffix("value"))))
                        )
                        )
                    )
                )

Then used the following to get the values.

var groups = response.Aggs.Nested("specifications").Terms("groups");

                foreach(var bucket in groups.Buckets)
                {
                    rtxAggs.AppendText(bucket.Key);
                    var values = bucket.Terms("attribute");
                    foreach(var valBucket in values.Buckets)
                    {
                        rtxAggs.AppendText(Environment.NewLine);
                        rtxAggs.AppendText("  " + valBucket.Key + "(" + valBucket.DocCount + ")");
                    }
                    rtxAggs.AppendText(Environment.NewLine);
                }

All seems to be working fine hopefully this helps some people, on to my next challenge of boosting fields and filtering on said aggregations.