public enum Department
{
    Icu,
    GeneralMedicine,
    Emergency,
    Cardiology,
    Surgery,
    Pediatrics
}

public static class DepartmentExtensions
{
    public static string ToDbString(this Department d) => d switch
    {
        Department.Icu             => "ICU",
        Department.GeneralMedicine => "GENERAL_MEDICINE",
        Department.Emergency       => "EMERGENCY",
        Department.Cardiology      => "CARDIOLOGY",
        Department.Surgery         => "SURGERY",
        Department.Pediatrics      => "PEDIATRICS",
        _ => throw new ArgumentOutOfRangeException(nameof(d))
    };

    public static Department FromDbString(string v) => v switch
    {
        "ICU"              => Department.Icu,
        "GENERAL_MEDICINE" => Department.GeneralMedicine,
        "EMERGENCY"        => Department.Emergency,
        "CARDIOLOGY"       => Department.Cardiology,
        "SURGERY"          => Department.Surgery,
        "PEDIATRICS"       => Department.Pediatrics,
        _ => throw new ArgumentOutOfRangeException(nameof(v), $"Unknown department: '{v}'")
    };
}