Elasticsearch case-insensitive searches

A simple normalizer called lowercase ships with elasticsearch and can be used.

Create Elasticsearch Index

PUT product-index
{
  "settings": {
    "analysis": {
      "normalizer": {
        "lowercaseNormalizer": {
          "type": "custom",
          "filter": ["lowercase", "asciifolding"]
        }
      }
    }
  },
  "mappings": {
    "properties": {
      "ProductName": {
        "type": "keyword",
        "normalizer": "lowercaseNormalizer"
      },
     "ProductCode": {
        "type": "keyword",
        "normalizer": "lowercaseNormalizer"
      },
      "ProductDescription": {
        "type": "text"
      },
      "ProductFamily": {
        "type": "keyword",
        "normalizer": "lowercaseNormalizer"
      },
      "Color": {
        "type": "keyword"
      }
    }
  }
}       
       

Adding sample data/records

        
#Add first Document in elasticsearch 
PUT /product-index/_doc/1
{
  "ProductName": "CBC Anti Virus",
  "ProductCode": "Network",
  "ProductDescription": "APAC",
  "ProductFamily": "Sales Cloud",
  "Color": "Silver"
}


PUT /product-index/_doc/2
{
  "ProductName": "CBC Esoteric",
  "ProductDescription": "CBC Panel - 1",
  "ProductFamily": "Hardware",
  "Color": "BLUE"
}

PUT /product-index/_doc/3
{
  "ProductName": "CBC Oncology",
  "ProductCode": "CBC Health",
  "ProductFamily": "Software"
}

PUT /product-index/_doc/4
{
  "ProductName": "CBC Panel",
  "ProductCode": "Secure Wifi",
  "ProductDescription": "Only One Charge Type"
}

PUT /product-index/_doc/5
{
  "ProductName": "CBC Panel (Invitro)",
  "ProductCode": "Secure Wifi",
  "ProductDescription": "CBC Panel",
  "ProductFamily": "Hardware",
  "Color": "GREEN"
}


PUT /product-index/_doc/6
{
  "ProductName": "CBC Panel - Beijing",
  "ProductCode": "CBC Panel",
  "ProductDescription": "Only One Charge Type",
  "ProductFamily": "Software",
  "Color": "BLUE"
}


PUT /product-index/_doc/7
{
  "ProductName": "Esoteric",
  "ProductCode": "CBC",
  "ProductFamily": "Marketing Cloud",
  "Color": "WHITE"
}


PUT /product-index/_doc/8
{
  "ProductName": "Oncology",
  "ProductCode": "Network",
  "ProductDescription": "CBC",
  "ProductFamily": "Sales Cloud",
  "Color": "WHITE"
}

        

View data/regcords

GET /product-index/_search

Search case-insensitive records

#Try 1
GET /product-index/_search
{
  "query": {
    "match": { "ProductFamily" : "hArdware"}
  }
}

#Try 2
GET /product-index/_search
{
  "query" : {
    "query_string" : {
      "query" : "*bei*",
      "fields"  : ["ProductName"]
    }
  }
}

#Try 3
GET /product-index/_search
{
  "query": {
    "query_string": {
      "query": "*Secure* OR *panel*",
      "default_field": "ProductCode"
    }
  }
}

#Try 4
GET /product-index/_search
{
  "query" : {
    "query_string" : {
      "query" : "*cHarge*",
      "fields"  : ["ProductDescription"]
    }
  }
}
       

Note

• Text fields are analyzed.
• For keyword fields we need to add custom elasticsearch setting for analysis.

Reference

• run elasticsearch locally run elasticsearch locally
• Documentation: Elasticsearch normalizer