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

Install the CData ADO.NET Provider for Parquet

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

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

Create a Parquet-Connected Blazor App

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

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

SELECT Parquet Data from the Blazor App

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

   Connect to your local Parquet file(s) by setting the URI connection property to the location of the Parquet file.

   For example: URI=C:/folder/table.parquet;

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

         @page "/"
         @using System.Data;
         @using System.Data.CData.Parquet;
         
         <h1>Hello, world!</h1>
         
         Welcome to your Data app.
         
         <div class="row">
             <div class="col-12">
         
                 @using (ParquetConnection connection = new ParquetConnection(
                   "URI=C:/folder/table.parquet;"))
                 {
                     var sql = "SELECT Id, Column1 FROM SampleTable_1 WHERE Column2 = 'SAMPLE_VALUE'";
                     var results = new DataTable();
         
                     ParquetDataAdapter dataAdapter = new ParquetDataAdapter(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 Parquet data as an HTML table in the Blazor app.

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