SQL Server的Exception Handling

   parameters.Add("user_name", userName);
   try
   {
   ExecuteCommand(procedureName, parameters);
   return true;
   }
   catch (Exception ex)
   {
   if (ex.Message == ErrorUserExists)
   {
   Console.WriteLine("The user \"{0}\" you specify is already existent!",userName);
   return false; ;
   }
   Console.WriteLine("A unhandled exception is thrown for some unknown reason!");
   return false;
   }
   }
  
   public static bool CreateRole(string roleName)
   {
   string procedureName = "P_ROLES_I";
   Dictionary<string, object> parameters = new Dictionary<string, object>();
   parameters.Add("role_id", Guid.NewGuid().ToString());
   parameters.Add("role_name", roleName);
   try
   {
   ExecuteCommand(procedureName, parameters);
   return true;
   }
   catch (Exception ex)
   {
   if (ex.Message==ErrorRoleExists)
   {
   Console.WriteLine("The role \"{0}\" you specify is already existent!",roleName);
   return false; ;
   }
   Console.WriteLine("A unhandled exception is thrown for some unknown reason!");
   return false;
   }
   }
  
   public static bool AddUserInRole(string userName, string roleName)
   {
   string procedureName = "P_USERS_IN_ROLES_I";
   Dictionary<string, object> parameters = new Dictionary<string, object>();
   parameters.Add("user_name", userName);
   parameters.Add("role_name", roleName);
   try
   {
   ExecuteCommand(procedureName, parameters);
   return true;
   }
   catch (Exception ex)
   {
   if (ex.Message==ErrorUserNotExists)
   {
   Console.WriteLine("The user \"{0}\" you specify is not existent!", userName);
   return false;
   }
   if (ex.Message==ErrorRoleNotExists)
   {
   Console.WriteLine("The role \"{0}\" you specify is not existent!",roleName);
   return false;
   }
   if (ex.Message == ErrorUserInRole)
   {
   Console.WriteLine("The user \"{0}\" is in the role \"{1}\"!",userName,roleName);
   return false;
   }
   Console.WriteLine("A unhandled exception is thrown for some unknown reason!");
   return false;
   }
   }
   public static void Clear()
   {
   ExecuteCommand("P_CLEAR_DATA", new Dictionary<string, object>());
   }
  
  6． Programs
  
  
  class Program
   {
   static void Main(string[] args)
   {
   Utility.Clear();
   if (Utility.CreateUser("Artech"))
   {
   Console.WriteLine("The user \"{0}\" has been sucessully created!", "Artech");
   }
   if (Utility.CreateUser("Artech"))
   {
   Console.WriteLine("The user \"{0}\" has been sucessully created!", "Artech");
   }
   if (Utility.CreateRole("Administrator"))
   {
   Console.WriteLine("\nThe role \"{0}\" has been sucessully created!", "Administrator");
   }
   if (Utility.CreateRole("Administrator"))
   {
   Console.WriteLine("The role \"{0}\" has been sucessully created!", "Administrator");
   }
   if (Utility.AddUserInRole("Artech", "Administrator"))
   {
   Console.WriteLine("\nThe user \"{0}\" has been successfully added in the role \"{1}\"", "Artech", "Administrator");
   }
  

（编辑：IT资讯之家 www.it55.com）