ElasticSearch：为什么query_string不区分大小写，而通配符区分大小写？

Question

Why is it when you do a query_string query on a field it's case insensitive and a wildcard query is case sensitive? I would've thought the two would behave similarly.

This query_string query returns results

{
  "query": {
    "bool" : {
      "must" : [ {
        "query_string" : {
          "query" : "name:*HILTON*"
        }
      } ]
    }
  }
}

Where as this wildcard query doesn't

{
  "query": {
    "bool" : {
      "must" : [{
        "wildcard" : {
          "name" : "*HILTON*"
        }
      } ]
    }
  }
}

Answer 1

This is because Wild card query works for not analyzed fields.

As per the documentation:

The prefix, wildcard, and regexp queries operate on terms. If you use them to query an analyzed field, they will examine each term in the field, not the field as a whole.

Wild card query matches documents that have fields matching a wildcard expression (not analyzed) .