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

Install the CData ADO.NET Provider for Greenplum

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

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

Create a Greenplum-Connected Blazor App

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

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

SELECT Greenplum Data from the Blazor App

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

   To connect to Greenplum, set the Server, Port (the default port is 5432), and Database connection properties and set the User and Password you wish to use to authenticate to the server. If the Database property is not specified, the default database for the authenticate user is used.

   For example: User=user;Password=admin;Database=dbname;Server=127.0.0.1;Port=5432;

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

         @page "/"
         @using System.Data;
         @using System.Data.CData.Greenplum;
         
         <h1>Hello, world!</h1>
         
         Welcome to your Data app.
         
         <div class="row">
             <div class="col-12">
         
                 @using (GreenplumConnection connection = new GreenplumConnection(
                   "User=user;Password=admin;Database=dbname;Server=127.0.0.1;Port=5432;"))
                 {
                     var sql = "SELECT Freight, ShipName FROM Orders WHERE ShipCountry = USA";
                     var results = new DataTable();
         
                     GreenplumDataAdapter dataAdapter = new GreenplumDataAdapter(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 Greenplum data as an HTML table in the Blazor app.

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