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

Getting Started

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Install the CData ADO.NET Provider for OData

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

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

Create a OData-Connected Blazor App

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

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

SELECT OData Services from the Blazor App

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

   The User and Password properties, under the Authentication section, must be set to valid OData user credentials. In addition, you will need to specify a URL to a valid OData server organization root or OData services file.

   For example: URL=http://services.odata.org/V4/Northwind/Northwind.svc;UseIdUrl=True;OData Version=4.0;Data Format=ATOM;

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

         @page "/"
         @using System.Data;
         @using System.Data.CData.OData;
         
         <h1>Hello, world!</h1>
         
         Welcome to your Data app.
         
         <div class="row">
             <div class="col-12">
         
                 @using (ODataConnection connection = new ODataConnection(
                   "URL=http://services.odata.org/V4/Northwind/Northwind.svc;UseIdUrl=True;OData Version=4.0;Data Format=ATOM;"))
                 {
                     var sql = "SELECT Orders.Freight, Customers.ContactName FROM Customers INNER JOIN Orders ON Customers.CustomerId=Orders.CustomerId";
                     var results = new DataTable();
         
                     ODataDataAdapter dataAdapter = new ODataDataAdapter(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 OData services as an HTML table in the Blazor app.

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