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

Install the CData ADO.NET Provider for CouchDB

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

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

Create a CouchDB-Connected Blazor App

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

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

SELECT CouchDB Data from the Blazor App

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

   Set the following to connect:

   • Url: The Url of your instance. For example: http://localhost:5984
   • User The Apache CouchDB user account used to authenticate.
   • Password The Apache CouchDB password associated with the authenticating user.

   For example: Url=http://localhost:5984;User=abc123;Password=abcdef;

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

    @page "/"
    @using System.Data;
    @using System.Data.CData.ApacheCouchDB;
    
    <h1>Hello, world!</h1>
    
    Welcome to your Data app.
    
    <div class="row">
    <div class="col-12">
    
    @using (ApacheCouchDBConnection connection = new ApacheCouchDBConnection(
    "Url=http://localhost:5984;User=abc123;Password=abcdef;"))
    {
    var sql = "SELECT MovieRuntime, MovieRating FROM Movies WHERE MovieRating = 'R'";
    var results = new DataTable();
    
    ApacheCouchDBDataAdapter dataAdapter = new ApacheCouchDBDataAdapter(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 CouchDB data as an HTML table in the Blazor app. 👁 Query CouchDB from Blazor app.
   

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