Here’s an example of a C# class that checks if MySQL is installed and, if not, installs it using the command-line tool “choco” (Chocolatey package manager):

using System;
using System.Diagnostics;

public class MySQLInstaller
{
    public static bool IsMySQLInstalled()
    {
        // Check if MySQL is installed by querying the version
        var process = new Process
        {
            StartInfo =
            {
                FileName = "mysql",
                Arguments = "--version",
                RedirectStandardOutput = true,
                UseShellExecute = false,
                CreateNoWindow = true
            }
        };

        process.Start();
        var output = process.StandardOutput.ReadToEnd();
        process.WaitForExit();

        return output.Contains("MySQL");
    }

    public static void InstallMySQL()
    {
        // Install MySQL using Chocolatey package manager
        var process = new Process
        {
            StartInfo =
            {
                FileName = "choco",
                Arguments = "install mysql",
                UseShellExecute = false,
                CreateNoWindow = true
            }
        };

        process.Start();
        process.WaitForExit();
    }

    public static void Main()
    {
        if (IsMySQLInstalled())
        {
            Console.WriteLine("MySQL is already installed.");
        }
        else
        {
            Console.WriteLine("MySQL is not installed. Installing...");
            InstallMySQL();
            Console.WriteLine("MySQL installation completed.");
        }
    }
}

In this example, the IsMySQLInstalled() method checks if MySQL is installed by running the mysql --version command and checking if the output contains “MySQL.” If it does, it returns true; otherwise, it returns false.

The InstallMySQL() method uses Chocolatey package manager to install MySQL by running the choco install mysql command.

In the Main() method, we first check if MySQL is already installed using IsMySQLInstalled(). If it is, we display a message stating that it’s already installed. Otherwise, we proceed with the installation by calling InstallMySQL() and display a completion message.

Note: This code assumes that you have Chocolatey package manager and the mysql package available for installation. Make sure you have Chocolatey installed on your system before running this code.