Examples of null values

Null Values

#Values like that will not be considered null 

POST null_values/_doc
{
  "user": [
    "jane",
    null
  ]
} 

#or

POST null_values/_doc
{
  "user": ""
} 

POST null_values/_doc
{
  "user": "null"
} 

POST null_values/_doc
{
  "user": "None"
} 

#Searching and aggregating in null values

#searching for documents the field exist
GET null_values/_search
{
  "query": {
    "bool": {
      "must": [
        {
          "exists": {
            "field": "user"
          }
        }
      ]
    }
  }
}

#searching for documents the field doesn't exist
GET null_values/_search
{
  "query": {
    "bool": {
      "must_not": [
        {
          "exists": {
            "field": "user"
          }
        }
      ]
    }
  }
}

#aggregating in null values
GET null_values/_search
{
  "size": 0, 
  "aggs": {
    "null_agg": {
      "missing": {
        "field": "user.keyword"
      }
    }
  }
}