Search ElasticSearch field contained in a value

问题:

I'm trying to run similar field query in ElasticSearch:

select * from products where 'milk' like '%'+name+'%'

Meaning I'm trying to find all the documents that the product name in this case is a sub string of 'milk'.

How can I do it?

回答1:

I would go with a custom analyzer leveraging ngrams. First create an index like this:

curl -XPUT 'localhost:9200/tests' -d '
{
    "settings" : {
        "analysis" : {
            "analyzer" : {
                "my_analyzer" : {
                    "tokenizer" : "ngrams"
                }
            },
            "tokenizer" : {
                "ngrams" : {
                    "type" : "nGram",
                    "min_gram" : "2",
                    "max_gram" : "10"
                }
            }
        }
    },
    "mappings": {
        "test": {
            "properties": {
                "product_name": {
                    "type": "string",
                    "analyzer": "standard",
                    "search_analyzer": "my_analyzer"
                }
            }
        }
    }
}'

Then you can index some data:

curl -XPOST 'localhost:9200/tests/test/_bulk' -d '
{"index":{}}
{"product_name": "bc"}
{"index":{}}
{"product_name": "cd"}
{"index":{}}
{"product_name": "def"}
'

And finally you can search like this:

curl -XPOST 'localhost:9200/tests/_search' -d '{
    "query": {
        "match": {
            "product_name": "abcde"
        }
    }
}'

And you'll get the first two documents bc and cd