Elasticsearch NEST API: How to write Query descriptor to implement search with Starts with? - elasticsearch

Question

Using Elasticsearch Nest Client to search for company name store in Elasticsearch. Here is sample of my queryExtentions.
I want to change it to make sure when I search for "Starbucks", it should only return record starting with letter "Starbucks". Currently it is rerurning all the records where it has "StarBucks".
Based on documentation, I need to search on "Keyword" filed in order to get the result.
Need sample code to how to achieve this.
****Elastic Search Index Column"
"name": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
Code*
var escapedSearchTerm = ElasticsearchQueryExtensions.EscapeQuery(companyName);
return new QueryContainerDescriptor<SearchResponseStorageContractV1>().Bool(b => b.Must(mu => mu
.QueryString(qs => qs
.AllowLeadingWildcard(true)
.AnalyzeWildcard(true)
.Fields(f => f.Field(s => s.Company.Name).Field(s => s.Organization.CommonName))
.Query(escapedSearchTerm)
)));

Answer 1

I am not familiar with Elastic Search Nest Client, but in JSON format you can implement search with functionality using prefix query
Adding a working example with index data,mapping,search query and search result
Index Mapping:
{
"settings": {
"analysis": {
"analyzer": {
"my_analyzer": {
"tokenizer": "keyword",
"filter": "lowercase"
}
}
}
},
"mappings": {
"properties": {
"name": {
"type": "text",
"analyzer": "my_analyzer"
}
}
}
}
Index Data:
{
"name":"Starbucks is a American multinational chain of coffeehouses"
}
{
"name":"coffee at Starbucks"
}
Search Query:
{
"query": {
"prefix": {
"name": {
"value": "Starbucks",
"case_insensitive": true // this param was introduced in 7.10.0
}
}
}
}
Search Result:
"hits": [
{
"_index": "67424740",
"_type": "_doc",
"_id": "1",
"_score": 1.0,
"_source": {
"name": "Starbucks is a American multinational chain of coffeehouses"
}
}
]