elasticsearch filter by length of a string field

Question

i am trying to get records the has in \'title\' more then X characters.

NOTE: not all records contains title field.

i have tried:

GET books/_         


        

Answer 1

You need to take into account that some documents might have a null title field. So you can use the groovy null-safe operator. Also make sure to use the POST method instead:

POST books/_search
{
    "filter" : {
          "script" : {
              "script" : "_source.title?.size() > 10"
          }
      }
}

Answer 2

You can also use custom tokenizers to count the number of characters. Check this answer for a possible help: https://stackoverflow.com/a/47556098/463846