Elasticsearch check if key exist in document

Question

I have key "field1" in the document of Elasticsearch. With mapping the field is an object. sometimes field does not exist, sometimes the field exists but is empty ([]), sometimes the field has the correct value -

"field1": [
   {"key" : "value"},
   {"key" : "value1"}
]

Now I want to write a filter with script query but get this kind of error

"caused_by": {
     "type": "illegal_argument_exception",
     "reason": "No field found for [field1] in mapping with types []"
   }

Even when I write a simpler query

if (doc.containsKey('field1')) {return true;} else {return false;}

but I have many documents which have the field. I think containsKey doesn't check the first level in a document but checks the full path.

Can somebody help me to check field1 exists in document or not

Answer 1

You can use the exists query.

{
    "query": {
        "exists": {
            "field": "field1"
        }
    }
}

As mentioned in the exists query document, if field as null or [](your case), it will not be indexed and exists query will not return that document.