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

Install the CData ADO.NET Provider for GraphQL

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

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

Create a GraphQL-Connected Blazor App

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

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

SELECT GraphQL Data from the Blazor App

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

   You must specify the URL of the GraphQL service. The driver supports two types of authentication:

   • Basic: Set AuthScheme to Basic. You must specify the User and Password of the GraphQL service.
   • OAuth 1.0 & 2.0: Take a look at the OAuth section in the Help documentation for detailed instructions.

   For example: AuthScheme=Basic;User=username;Password=password;URL=https://mysite.com;

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

         @page "/"
         @using System.Data;
         @using System.Data.CData.GraphQL;
         
         <h1>Hello, world!</h1>
         
         Welcome to your Data app.
         
         <div class="row">
             <div class="col-12">
         
                 @using (GraphQLConnection connection = new GraphQLConnection(
                   "AuthScheme=Basic;User=username;Password=password;URL=https://mysite.com;"))
                 {
                     var sql = "SELECT Name, Email FROM Users WHERE UserLogin = 'admin'";
                     var results = new DataTable();
         
                     GraphQLDataAdapter dataAdapter = new GraphQLDataAdapter(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 GraphQL data as an HTML table in the Blazor app.

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