How do I control which database to use when a Blazor Server app starts?

Question

How do I control which database to use when a Blazor Server app starts?

Falanga, Rod, DOH 290

I'm working on a rewrite of an old WebForms application. I want to be able to control, through a GitHub Action running in a self-hosted runner, which database (test or production) the application should run against. I thought I could do this with the OnInitializedAsync() method, but I realized that I'm overriding it:

protected override async Task OnInitializedAsync()
{
    try
    {
        // Call the Jobs API endpoint
        var response = await Http.GetFromJsonAsync<APIResponse>("api/getjobs/true/true");   // getjobs/{prodConn}/{Active}

        if (response != null && response.IsSuccess && response.Result is JsonElement jsonElement)
        {

	// The rest left off for brevity

I would think I couldn't pass in a parameter to OnInitializedAsync(), without dropping override. I looked elsewhere, and came across Blazor - Lifecycle Methods. The OnParametersSet and OnParametersSetAsync methods looked very promising. However, I then read that those parameters come from the querystring. I don't want the user to be able to change which database they run against by changing the querystring. So, how do I change what database is accessed, when a GitHub Action builds and deploys the app?

2 answers

Your answer

Answer 1

Bruce (SqlWork.com) 79,101 Volunteer Moderator

Typically you would use GitHub actions variables to modify the appsettings.

https://github.com/IntentArchitect/Docs/blob/master/articles/module-building/templates-csharp/how-to-update-appsettings-json-files/how-to-update-appsettings-json-files.md

Answer 2

Raymond Huynh (WICLOUD CORPORATION) 620 Microsoft External Staff

Here’s how you can do it:

1. Set Environment Variables in GitHub Actions:

In your GitHub Actions workflow, set the ASPNETCORE_ENVIRONMENT variable to specify which environment the app should use (e.g., Production or Staging).

2. Use Environment-Specific appsettings Files:

In your project, create different appsettings files for each environment, each with its own connection string:

appsettings.Production.json (for production DB)
appsettings.Staging.json (for test DB)

3. Update appsettings in CI/CD:

If you need to dynamically update the connection string or other settings during your GitHub Action, you can add a step to modify the appropriate appsettings file before deploying.

Here’s a helpful guide:

[How to update appsettings.json files in GitHub Actions] (https://github.com/IntentArchitect/Docs/blob/master/articles/module-building/templates-csharp/how-to-update-appsettings-json-files/how-to-update-appsettings-json-files.md)

This approach keeps your database selection secure and controlled by your deployment process, not by user input or code changes.

Hope this helps!

Raymond Huynh (WICLOUD CORPORATION) 620 Reputation points Microsoft External Staff

2025-07-08T10:31:52.3833333+00:00

Please let me know if you need any further help!
Falanga, Rod, DOH 290 Reputation points

2025-07-10T18:11:02.4866667+00:00

Something I am not clear on concerning Intent Architect, is when it gets invoked. Does that happen when I create the Visual Studio project? Or does it happen later, like when the GitHub Action runs?
Raymond Huynh (WICLOUD CORPORATION) 620 Reputation points Microsoft External Staff

2025-07-11T02:39:21.41+00:00
Intent Architect is a code generation and modeling tool that works at design time, not during your GitHub Actions or runtime. It gets invoked when you're actively developing in Visual Studio - typically when you:

Create/modify Intent Architect models - When you define your domain models, entities, and relationships in the Intent Architect designer

Generate code - When you trigger code generation from your models (usually through Visual Studio extensions or the Intent Architect tooling)

Apply patterns - When you use Intent Architect's pattern system to apply architectural patterns to your codebase

The link I shared in my previous answer was just a reference for how to update appsettings.json files during CI/CD - it wasn't specifically about Intent Architect itself. Intent Architect is separate from your deployment process.

For your Blazor Server app database control scenario, you don't actually need Intent Architect at all. The approach I suggested (environment-specific appsettings files + GitHub Actions environment variables) is a standard .NET pattern that works independently of any code generation tools.
Raymond Huynh (WICLOUD CORPORATION) 620 Reputation points Microsoft External Staff

2025-08-12T10:03:00.78+00:00

Hi,

If you find this solution helpful, feel free to interact with system accordingly!

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How do I control which database to use when a Blazor Server app starts?

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