Connect to Cassandra 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 Apache Cassandra can be used with standard ADO.NET interfaces, such as LINQ and Entity Framework, to interact with live Cassandra 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 Cassandra using standard SQL queries.

Install the CData ADO.NET Provider for Apache Cassandra

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

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

Create a Cassandra-Connected Blazor App

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

1. Create a Blazor project on Visual Studio.
👁 Create a Blazor app project.

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.Cassandra.dll, typically located at C:\Program Files\CData\CData ADO.NET Provider for Apache Cassandra\lib etstandard2.0).
👁 Reference ADO.NET for Cassandra .dll in the Blazor app.

SELECT Cassandra Data from the Blazor App

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

   Set the Server, Port, and Database connection properties to connect to Cassandra. Additionally, to use internal authentication set the User and Password connection properties.

   For example: Database=MyCassandraDB;Port=7000;Server=127.0.0.1;

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

    @page "/"
    @using System.Data;
    @using System.Data.CData.Cassandra;
    
    <h1>Hello, world!</h1>
    
    Welcome to your Data app.
    
    <div class="row">
    <div class="col-12">
    
    @using (CassandraConnection connection = new CassandraConnection(
    "Database=MyCassandraDB;Port=7000;Server=127.0.0.1;"))
    {
    var sql = "SELECT City, SUM(TotalDue) FROM Customer GROUP BY City";
    var results = new DataTable();
    
    CassandraDataAdapter dataAdapter = new CassandraDataAdapter(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 Cassandra data as an HTML table in the Blazor app. 👁 Query Cassandra from Blazor app.
   

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