Single query for terms aggregation with or without nested objects-CodePudding

I want to get an aggregation of all the unique values for a field. I found that this query works well for a "simple" field with no nested type in the json path.

GET /_search
{
  "aggs": {
    "myResult": {
      "terms": { "field": "school.student.name" }
    }
  },
  "size": 0
}

However, when one of the objects in the path is of nested type, I have to make a different request. Let say student is nested just for the example, then I change the query like this:

GET /_search
{
  "aggs": {
    "myResult": {
      "nested": {
         "path": "school.student"
      }
      "aggs": {
        "myResult2": {
           "terms": { "field": "school.student.name" }
        }
      }
    }
  },
  "size": 0
}

However, in my app, I only have the json path such as "school.student.name" but I do not know if there is a nested object, and who is the nested. I did not find any solution to make a single request that could work to handle both case, and I end up with a configuration file where I have to explicitly list all the nested path that I have in my elastic database, to build the correct request. However, if I have hundreds of fields, this is not maintainable. Does elastic really do not implement such a simple and basic feature?

I just want to get all unique values corresponding to a json path in my elastic database.

Would you have a better solution than the config file?

CodePudding user response：

No need for configuration file, you should directly retrieve the mapping as it is currently stored in ES, parse it and you'd always have the right fields.