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Elasticsearch NEST: ordering terms with multiple criteria

Using NEST, I need to be able to order the aggregation of terms with multiple criteria (ElasticSearch 1.5 or newer required). For example:

"order": [{"avg_rank": "desc"}, {"avg_score": "desc"}]

This works great using the original JSON I created to test that I was getting the expected behavior. Now trying to translate this to code using the NEST library, I can't see how this would be accomplished.

The method OrderDescending()

has only one implementation, which takes a string for the key. I need a method of type "params" that can take a list of items OrderDescending()

and / or OrderAscending()

.

  • Is there a way to do this in NEST that I am overlooking?
  • Is there a way in NEST to get around this where I can add some raw JSON where I need it?

FWIW, I use the "free" style to create my queries.

EDIT: I see that using the object initializer syntax I could manually create a dictionary and add criteria elements. The problem is that I have a lot of code written in "free" syntax. Thus,

  1. Is there a way to use an "object initializer" object and convert it to a "free" descriptor? In this case, does Term Aggregator refer to the term Aggregation?

EDIT 2: First I had to mention that I already tried it .OrderDescending("avg_rank").OrderDescending("avg_score")

. It just took the last link in the chain. Looking at the code, I can see why. Each call will OrderDescending

blindly publish the dictionary instead of checking if it has already been created and adding a new key to the dictionary if it already exists.

Based on this, I believe this is a bug for which I have introduced a report here: OrderDescending and OrderAscending cannot be linked for multi-criteria order

EDIT 3: I appreciate all of the replies (some of them are being removed) because they help manage this and are responsible for making these changes. I also had to mention first that I found that:

"order": { "avg_rank": "desc", "avg_score": "desc" }

does not work. I don't know why exactly, but ES will only use the latter. This is a list of dictionaries as shown in my example above. I have verified that it correctly subscribes the aggregation in the second item. Thus, the underlying object cannot be entered like a simple dictionary. I also added this information to the bug report I created (as pointed out in EDIT 2 ).

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2 answers


Martijn Laarman of the NEST team was very helpful and helpful to ensure that the bug I reported in EDIT 2 of the description above is addressed. A fix can be found in the comments to the same bug report: Work on ordering the aggregation of the NIST library according to multiple criteria .



Note that it provided work for both the object initializer and fluent syntax (the one I need).

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If you are using fluent syntax, you can simply chain the sorts together.

Example:

    var esClient = ninjectKernel.Get<IElasticClient>();
    var query = esClient.Search<RedemptionES>(s=> s
        .SortAscending(a=>a.Date)
        .SortDescending(d=>d.Input.User.Name)
        );


Answer:

{
  "sort": [
    {
      "@timestamp": {
        "order": "asc"
      }
    },
    {
      "input.user.name": {
        "order": "desc"
      }
    }
  ]
}
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