Adding documents and querying Elasticsearch

Elasticsearch is an opensource text search engine. It is accessible using RESTFul API’s and uses JSON documents to store data. It allows users to search very large amounts of data at a very high speed. Since it is written using the Java programming language it can run on many platforms. See this blog post on how to install, configure and start Elasticsearch 8.5.0.

In this blog post I will show you how you can create an index, insert data into the index and query the data in Elasticsearch. In the rest of this post, I assume that you are executing the curl commands from the host that is running the Elasticsearch server. Hence all the curl queries are directed to localhost. If you are running the curl commands from a client machine, replace localhost with your actual hostname (or ip address) for the server running Elasticsearch.

Inserting a single document into an Index

curl -k -POST https://localhost:9200/messages/_doc -H "Content-Type: application/json" -d'
  "msg_id" : 1,
  "msg_case_id" : 55,
  "msg_message" : "Hi This is xyz from def media company"
}' --user "elastic:Password1"

In the command shown above, “messages” is the Index that we are inserting the document into. We are also providing the Elasticsearch username and password to set the POST requirement to Elasticsearch. The -k is used to tell curl to accept the selft signed certificated from Elasticsearch.

Bulk inserting documents into an Index

First create a file named msg.json with the following lines

{ "msg_id" : 1, "msg_case_id" : 55, "msg_message" : "Hi This is xyz from def media company" }
{ "msg_id" : 2, "msg_case_id" : 55, "msg_message" : "We provide targeted advertising to different platforms" }
{ "msg_id" : 3, "msg_case_id" : 55, "msg_message" : "Includes TV, Radio, Online, Social Media etc" }
{ "msg_id" : 4, "msg_case_id" : 55, "msg_message" : "Our conversion ratios are very high" }
{ "msg_id" : 5, "msg_case_id" : 55, "msg_message" : "provides search engine optimization" }

You can batch insert all the documents in the file above to the Elasticsearch index named “messages” using the command below

curl -k -X POST https://localhost:9200/messages/_bulk?pretty -H "Content-Type: application/x-ndjson" --user "elastic:Password1" --data-binary @msg.json

Note that we are using the content-type x-ndjson here

You can delete all the documents in the “messages” index, using the command below

curl -k -XPOST 'https://localhost:9200/messages/_delete_by_query?conflicts=proceed&pretty' -H 'Content-Type: application/json' --user "elastic:Password1" -d'
    "query": {
        "match_all": {}

Querying documents

You can query all the documents from the “messages” index using the command below

curl -k -X GET 'https://localhost:9200/messages/_search' --user "elastic:Password1"

You can query specific documents that match specific criteria using the command below

curl -k -X POST "https://localhost:9200/messages/_search?pretty" -H 'Content-Type: application/json' --user "elastic:Password1" -d'
  "query": {
    "bool": {
      "filter": [
        "term": {
          "msg_message": "ratio"
        "term": {
          "msg_id": "4"

The above query will display the documents where the word ratio occurs in the msg_message property and when the msg_id property is 4.

In this blog post I have shown you how to insert documents into Elasticsearch indexes and query them.

Leave a Reply

Your email address will not be published. Required fields are marked *