CODEWITHSUNDEEP
elasticsearch
Giovanni Caporaletti
Giovanni Caporaletti

Reputation: 5556

Elasticsearch bool filter for multiple conditions on same element of array

I'm trying to create a query/filter that matches a document only if a number of conditions are met on the same item of an array.

Let's say this is the document:

{
  arr: [
    { "f1" : "a" , f2 : true },
    { "f1" : "b" , f2 : false}
  ]
}

I want to be able to retrieve documents that have N conditions matching on the same element. For example: arr.f1 == "a" AND arr.f2 == true should match the document but arr.f1 == "b" AND arr.f2 == true should not.

I'm trying nested bool filters (I have other filters apart from this one) but it doesn't work, something in the lines of

"bool" : {
    "must": [
        { some other filter },
        {"bool": {"must" : [
            {"term" : {"arr.f1" : "a"}},
            {"term" : {"arr.f2" : true}},
        ] }}
    ]
}

Any idea how to do that? thanks

edit: I changed the mapping and now a nested query works as per Val's response. I'm now not able to do an "exists" filter on the nested field:

A simple { "filter" : {"exists" : { "field" : "arr" } } } search returns no hits. How do I do that?

edit: It looks like I need to do a nested exists filter to check that a field inside the nested object exists. something like:

"filter" : {
       "nested" : {"path" : "arr", "filter" : {"exists" : { "field" : "f1" } }}
}

edit: argh - now highlight doesn't work anymore: 

   "highlight" : {
        "fields" : [
            {"arr.f1" : {}},
        ]
    }

Worked around that by adding include_in_parent : true and querying both the nested field and the root object. It's just awful. If anyone has a better idea, they're more than welcome!

{   
    "query" : {
        "bool" : {
            "must": [
                {"term" : { "arr.f1" : "a" }},
                { "nested" : { "path" : "arr", 
                   "query" :  { "bool" : { "must" : [ 
                        {"term" : { "arr.f1" : "a" }},
                        {"term" : { "arr.f2" : true }}
                   ] } } 
                }}
            ]
        }
    },
    "highlight" : {
        "fields" : [
            {"arr.f1" : {}},
        ]
    }
}

In case you're wondering: it's legacy stuff. I can't reindex right now (that would be the obvious solution) and I need a quick & dirty workaround

Upvotes: 6

Views: 4056

Answers (1)

Val
Val

Reputation: 217314

You need to set the type of your arr field as nested like this:

{
    "your_type": {
        "properties": {
            "arr": {
                "type": "nested",
                "properties": {
                    "f1": {"type":"string"},
                    "f2": {"type":"boolean"}
                }
            }
        }
    }
}

Then you need to use a nested query:

{
    "nested" : {
        "path" : "arr",
        "query" : {
            "bool" : {
                "must" : [
                    {
                        "term" : {"arr.f1" : "a"}
                    },
                    {
                        "term" : {"arr.f2" : true}
                    }
                ]
            }
        }
    }
}

Your exists filter needs to specify the full field path

"filter" : {
       "nested" : {"path" : "arr", "filter" : {"exists" : { "field" : "arr.f1" } }}
}

Upvotes: 6

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