In this article I will explain with an example, how to use System.Data.SqlClient package in ASP.Net Core (.Net Core 8) Razor Pages.
Note: For beginners in ASP.Net Core (.Net Core 8) Razor Pages, please refer my article ASP.Net Core 8 Razor Pages: Hello World Tutorial with Sample Program example.
 
 

Explanation

By default, like ASP.Net, ASP.Net MVC and .Net Core 3.0 Razor Pages, System.Data.SqlClient package is not available in ASP.Net Core (.Net Core 8) Razor Pages.
Using System.Data.SqlClient in .Net Core 8.0 Razor Pages
 
Thus, in order to use System.Data.SqlClient package, you need to install the System.Data.SqlClient package from Nuget using Package Manager Console.
 
 

Downloading System.Data.SqlClient package

You will need to install the System.Data.SqlClient package using the following command.
Install-Package System.Data.SqlClient -Version 4.8.5
 
Using System.Data.SqlClient in .Net Core 8.0 Razor Pages
 
Using System.Data.SqlClient in .Net Core 8.0 Razor Pages
 
Once System.Data.SqlClient package is successfully installed, you will need to import the System.Data.SqlClient namespace.
As you can see, the SqlConnection class is available to use.
Using System.Data.SqlClient in .Net Core 8.0 Razor Pages