How to do a wildcard or regex match on _id in elasticsearch?

Question

From below sample elasticsearch data I want to apply wildcard say *.000ANT.* on _id so as to fetch all docs whose _id contains 0

Answer 1

You have two options here, the first is to use partial matching, which is easiest by wrapping a query with wildcards similar to other answers. This works on not_analyzed fields and is case sensitive.

POST /my_index/my_type/_search
{
"query": {
    "wildcard": {
       "_id": {
          "value": "*000ANT*"
       }
    }
}
}

The second option is to use ElasticSearch analyzers and proper mapping to describe the functionality you are looking for, you can read about those here.

The basic premise is that you introduce an analyzer in your mapping which has a tokenizer, which will break strings down into smaller tokens that then can be matched. Doing a simple query search for "000ANT" on the tokenized _id field will return all result with that string.