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

Install the CData ADO.NET Provider for CockroachDB

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

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

Create a CockroachDB-Connected Blazor App

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

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.CockroachDB.dll, typically located at C:\Program Files\CData\CData ADO.NET Provider for CockroachDB\lib etstandard2.0).

SELECT CockroachDB Data from the Blazor App

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

   Set the following to connect to CockroachDB.

   • Server: The host name or IP address of the server.
   • Port: The port number of the CockroachDB server. If not specified, the default port is 26257.
   • Database: The name of the Cockroach database. If not specified, you connect to the user's default database.
   • User: The Cockroach DB user account used to authenticate.
   • Password: The password used to authenticate the user.

   For example: User=root;Password=root;Database=system;Server=localhost;Port=26257

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

         @page "/"
         @using System.Data;
         @using System.Data.CData.CockroachDB;
         
         <h1>Hello, world!</h1>
         
         Welcome to your Data app.
         
         <div class="row">
             <div class="col-12">
         
                 @using (CockroachDBConnection connection = new CockroachDBConnection(
                   "User=root;Password=root;Database=system;Server=localhost;Port=26257"))
                 {
                     var sql = "SELECT ShipName, ShipCity FROM Orders WHERE ShipCountry = 'USA'";
                     var results = new DataTable();
         
                     CockroachDBDataAdapter dataAdapter = new CockroachDBDataAdapter(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 CockroachDB data as an HTML table in the Blazor app.

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