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

Install the CData ADO.NET Provider for CSV

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

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

Create a CSV-Connected Blazor App

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

1. Create a Blazor project on Visual Studio.
👁 Create a Blazor app project.

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.CSV.dll, typically located at C:\Program Files\CData\CData ADO.NET Provider for CSV\lib etstandard2.0).
👁 Reference ADO.NET for CSV .dll in the Blazor app.

SELECT CSV Data from the Blazor App

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

   Connecting to Local or Cloud-Stored (Box, Google Drive, Amazon S3, SharePoint) CSV Files

   CData Drivers let you work with CSV files stored locally and stored in cloud storage services like Box, Amazon S3, Google Drive, or SharePoint, right where they are.

   Setting connection properties for local files

   Set the URI property to local folder path.

   Setting connection properties for files stored in Amazon S3

   To connect to CSV file(s) within Amazon S3, set the URI property to the URI of the Bucket and Folder where the intended CSV files exist. In addition, at least set these properties:

   • AWSAccessKey: AWS Access Key (username)
   • AWSSecretKey: AWS Secret Key

   Setting connection properties for files stored in Box

   To connect to CSV file(s) within Box, set the URI property to the URI of the folder that includes the intended CSV file(s). Use the OAuth authentication method to connect to Box.

   Dropbox

   To connect to CSV file(s) within Dropbox, set the URI proprerty to the URI of the folder that includes the intended CSV file(s). Use the OAuth authentication method to connect to Dropbox. Either User Account or Service Account can be used to authenticate.

   SharePoint Online (SOAP)

   To connect to CSV file(s) within SharePoint with SOAP Schema, set the URI proprerty to the URI of the document library that includes the intended CSV file. Set User, Password, and StorageBaseURL.

   SharePoint Online REST

   To connect to CSV file(s) within SharePoint with REST Schema, set the URI proprerty to the URI of the document library that includes the intended CSV file. StorageBaseURL is optional. If not set, the driver will use the root drive. OAuth is used to authenticate.

   Google Drive

   To connect to CSV file(s) within Google Drive, set the URI property to the URI of the folder that includes the intended CSV file(s). Use the OAuth authentication method to connect and set InitiateOAuth to GETANDREFRESH.

   For example: URI=/PATH/TO/MyCSVFilesFolder;

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

    @page "/"
    @using System.Data;
    @using System.Data.CData.CSV;
    
    <h1>Hello, world!</h1>
    
    Welcome to your Data app.
    
    <div class="row">
    <div class="col-12">
    
    @using (CSVConnection connection = new CSVConnection(
    "URI=/PATH/TO/MyCSVFilesFolder;"))
    {
    var sql = "SELECT City, SUM(TotalDue) FROM Customer GROUP BY City";
    var results = new DataTable();
    
    CSVDataAdapter dataAdapter = new CSVDataAdapter(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 CSV data as an HTML table in the Blazor app. 👁 Query CSV from Blazor app.
   

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