如何在SQL(nvarchar(50)字段)中插入类参数，并在c#中使用

我将从cls1插入任何数据到SQL Server (Nvarchar(50)列)。这里显示的代码是来自我的项目

的示例

请帮帮我

感谢

class Cls1
{
    public static string projectid;
    public static string projectname;
}
using (SqlCommand cmdInsert = con.CreateCommand())
{
    cmdInsert.CommandType = CommandType.Text;
    cmdInsert.CommandText = string.Format(@"INSERT INTO total(projectid)" +
                                           "values(@projectid)");
    cmdInsert.Parameters.AddWithValue("@projectid", (ClsPQR1. projectid));
}

using (SqlCommand cmdInsert = con.CreateCommand())
{
    cmdInsert.CommandType = CommandType.Text;
    cmdInsert.CommandText = string.Format(@"INSERT INTO total(projectid)" +
                                           "values(@projectid)");
    cmdInsert.Parameters.AddWithValue("@projectid", (ClsPQR1. projectid));
    cmdInsert.ExecuteNonQuery();
}