вам нужно будет использовать ProcessStartInfo
под using System.Diagnostics;
// Calls the sqlcmd
ProcessStartInfo info = new ProcessStartInfo("sqlcmd", @" -S .\sqlexpress -i C:\YourFileName.sql");
// Indicades if the Operative System shell is used, in this case it is not
info.UseShellExecute = false;
//No new window is required
info.CreateNoWindow = true;
//The windows style will be hidden
info.WindowStyle = ProcessWindowStyle.Hidden;
//The output will be read by the starndar output process
info.RedirectStandardOutput = true;
Process proc = new Process();
proc.StartInfo = info;
//Start the process
proc.Start();