Find empty strings in elasticsearch

Question

I\'m trying to _search documents that has some specific value in the field.

{
  \"query\": {
      \"bool\": {
        \"must\": [
         {\"f         


        

Answer 1

the "missing" does work only for null values or not being there at all. Matching empty string was already answered here: https://stackoverflow.com/a/25562877/155708