Connect to Elasticsearch Data from Blazor Apps

Blazor is a framework for developing modern, client-side web UIs using .NET technology. Instead of coding in JavaScript, developers can use the familiar C# language and .NET libraries to build app UIs.

The CData ADO.NET Provider for Elasticsearch can be used with standard ADO.NET interfaces, such as LINQ and Entity Framework, to interact with live Elasticsearch data. Since Blazor supports .NET Core, developers can use CData ADO.NET Providers in Blazor apps. In this article, we will guide you to build a simple Blazor app that talks to Elasticsearch using standard SQL queries.

Getting Started

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Install the CData ADO.NET Provider for Elasticsearch

CData ADO.NET Providers allow users to access Elasticsearch just like they would access SQL Server, using simple SQL queries.

Install the Elasticsearch ADO.NET Data Provider from the CData website or from NuGet. Search NuGet for "Elasticsearch ADO.NET Data Provider."

Create a Elasticsearch-Connected Blazor App

Start by creating a Blazor project that references the CData ADO.NET Provider for Elasticsearch

1. Create a Blazor project on Visual Studio.

2. From the Solution Explorer, right click Dependencies, then click Add Project Reference.
3. In the Reference Manager, click the Browse button, and choose the .dll file of the installed ADO.NET Provider (e.g. System.Data.CData.Elasticsearch.dll, typically located at C:\Program Files\CData\CData ADO.NET Provider for Elasticsearch\lib etstandard2.0).

SELECT Elasticsearch Data from the Blazor App

1. Open the Index.razor file from the Project page.
2. In a ElasticsearchConnection object, set the connection string:

   Set the Server and Port connection properties to connect. To authenticate, set the User and Password properties, PKI (public key infrastructure) properties, or both. To use PKI, set the SSLClientCert, SSLClientCertType, SSLClientCertSubject, and SSLClientCertPassword properties.

   The data provider uses X-Pack Security for TLS/SSL and authentication. To connect over TLS/SSL, prefix the Server value with 'https://'. Note: TLS/SSL and client authentication must be enabled on X-Pack to use PKI.

   Once the data provider is connected, X-Pack will then perform user authentication and grant role permissions based on the realms you have configured.

   For example: Server=127.0.0.1;Port=9200;User=admin;Password=123456;

3. The code below creates a simple Blazor app for displaying Elasticsearch data, using standard SQL to query Elasticsearch just like SQL Server.

         @page "/"
         @using System.Data;
         @using System.Data.CData.Elasticsearch;
         
         <h1>Hello, world!</h1>
         
         Welcome to your Data app.
         
         <div class="row">
             <div class="col-12">
         
                 @using (ElasticsearchConnection connection = new ElasticsearchConnection(
                   "Server=127.0.0.1;Port=9200;User=admin;Password=123456;"))
                 {
                     var sql = "SELECT Orders.Freight, Customers.ContactName FROM Customers INNER JOIN Orders ON Customers.CustomerId=Orders.CustomerId";
                     var results = new DataTable();
         
                     ElasticsearchDataAdapter dataAdapter = new ElasticsearchDataAdapter(sql, connection);
                     dataAdapter.Fill(results);
         
                     <table class="table table-bordered">
                         <thead class="thead-light">
                             <tr>
                                 @foreach (DataColumn item in results.Rows[0].Table.Columns)
                                 {
                                     <th scope="col">@item.ColumnName</th>
                                 }
                             </tr>
                         </thead>
                         <tbody>
                             @foreach (DataRow row in results.Rows)
                             {
                                 <tr>
                                     @foreach (var column in row.ItemArray)
                                     {
                                         <td>@column.ToString()</td>
                                     }
                                 </tr>
                             }
                         </tbody>
                     </table>
                 }
             </div>
         </div>
       

4. Rebuild and run the project. The ADO.NET Provider renders Elasticsearch data as an HTML table in the Blazor app.

   At this point, you have a Elasticsearch-connected Blazor app, capable of working with live Elasticsearch data just like you would work with a SQL Server instance. Download a free, 30-day trial and start working with live Elasticsearch data in your Blazor apps today.