How to find word 'food2u' by search 'food' in Elasticsearch? - elasticsearch

Question

I am a rookie who just started learning elasticsearch,And I want to find word like 'food2u' by search keyword 'food'.But I can only get the results like 'Food Repo','Give Food' etc. The field's Mapping is 'text' and this is my query
GET api/_search
{"query": {
"match": {
"Name": {
"query": "food"
}
}
},
"_source":{
"includes":["Name"]
}
}

Answer 1

You are getting the results like 'Food Repo','Give Food', as the text field uses a standard analyzer if no analyzer is specified. Food Repo gets tokenized into food and repo. Similarly Give Food gets tokenized into give and food.
But food2u gets tokenized into food2u. Since there is no matching token ("food"), you will not get the food2u document.
You need to use edge_ngram tokenizer to do a partial text match.
Adding a working example with index data, mapping, search query and search result
Index Mapping:
{
"settings": {
"analysis": {
"analyzer": {
"my_analyzer": {
"tokenizer": "my_tokenizer"
}
},
"tokenizer": {
"my_tokenizer": {
"type": "edge_ngram",
"min_gram": 4,
"max_gram": 10,
"token_chars": [
"letter",
"digit"
]
}
}
},
"max_ngram_diff": 10
},
"mappings": {
"properties": {
"name": {
"type": "text",
"analyzer": "my_analyzer"
}
}
}
}
Index Data:
{
"name":"food2u"
}
Search Query:
{
"query": {
"match": {
"name": "food"
}
}
}
Search Result:
"hits": [
{
"_index": "67552800",
"_type": "_doc",
"_id": "1",
"_score": 0.2876821,
"_source": {
"name": "food2u"
}
}
]
If you don't want to change the mapping, you can even use a wildcard query to return the matching documents
{
"query": {
"wildcard": {
"Name": {
"value": "food*"
}
}
}
}
OR you can even use query_string with wildcard
{
"query": {
"query_string": {
"query": "food*",
"fields": [
"Name"
]
}
}
}