Check if document exists or not in elasticsearch - elasticsearch

Question

I want to check if a document with specific field value does exist or not in elasticsearch.
I have gone through internet but only found how to check if a field exists or not.
My Index/Type is
/twitter/user
username is one field in document.
I want to check if username="xyz" exists or not in this Type.

Answer 1

You can query with size 0. total value will give you an idea that doc exists or not.
GET /twitter/user/_search
{"size": 0,
"query": {"match": {
"username": "xyz"
}}}
Edited --
_count api can be used as well.
GET /twitter/user/_count
{ "query": {"match": {
"username": "xyz"
}}}

Answer 2

From the documentation:
If all you want to do is to check whether a document exists—you’re not interested in the content at all—then use the HEAD method instead of the GET method. HEAD requests don’t return a body, just HTTP headers:
curl -i -XHEAD http://localhost:9200/twitter/user/userid
Elasticsearch will return a 200 OK status code if the document exists ... and a 404 Not Found if it doesn’t exist
Note: userid is the value of the _id field.

Answer 3

simply search the document, if it exists it will return result otherwise not
http://127.0.0.1:9200/twitter/user/_search?q=username:xyz
and the exact what are you looking for is
http://127.0.0.1:9200/twitter/user/_search/exists?q=username:xyz
it will return exists true or false
{
"exists": false
}

Answer 4

You can use term query with size 0. See below query for reference:
POST twitter/user/_search
{
"query": {
"term": {
"username": "xyz"
}
},
"size" : 0
}
Response:
{
"took": 1,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0,
"hits": []
}
}
You will get total document count in hits.total and then you can check for count > 0