Input string was not in a correct format.[Answered] RSS

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  donpisci

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  176 Posts

  Input string was not in a correct format.

  Jun 27, 2010 12:30 PM|donpisci|LINK

  Hi folks,

  I'm getting the above error when I get to the following line:

  string result = Convert.ToString(command.ExecuteScalar());

  am really confused because everything I've read tells me that that line is correct!

  Thanks in advance!

  
  

  My code is as follows:

  public bool Login(string userName, string password)
      {
          // read the coonection string from web.config
          string conString = ConfigurationManager.ConnectionStrings["MySqlDatabase"].ConnectionString;
  
  
          //Encrypt encrypt = new Encrypt();
          //encrypt.EncodePassword(password);
          using (MySql.Data.MySqlClient.MySqlConnection mySqlConn = new MySql.Data.MySqlClient.MySqlConnection(conString))
          {
              try
              {
  
  
                  mySqlConn.Open();
                  MySql.Data.MySqlClient.MySqlCommand command = new MySql.Data.MySqlClient.MySqlCommand
                                       ("SELECT UserName FROM Users WHERE UserName = @UserName AND Password = MDS('@Password')");
                  
  
                  command.Parameters.Add("@UserName", SqlDbType.Char).Value = userName;
                  command.Parameters.Add("@Password", SqlDbType.VarChar).Value = password;
  
  
                  command.Connection = mySqlConn;
  
  
                  string result = Convert.ToString(command.ExecuteScalar());
  
  
                  if (string.IsNullOrEmpty(result))
                  {
                      //invalid user/password , return flase
                      return false;
                  }
                  else
                  {
                      // valid login
                      return true;
                  }
              }
              catch (Exception)
              {
  
  
                  throw;
              }
  
  
          }
      }
  }

  
  
  

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  SGWellens

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  Re: Input string was not in a correct format.

  Jun 27, 2010 12:37 PM|SGWellens|LINK

  As a general rule of thumb:  NEVER nest function calls.

  Try this:

  Object Scalar = command.ExecuteScalar()

  string result = Scalar.ToString();

  Steve Wellens
  
  My blog
  
• • Reply
  donpisci

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  176 Posts

  Re: Input string was not in a correct format.

  Jun 27, 2010 12:51 PM|donpisci|LINK

  Hi mate,

  Thanks for that, I copied it exactly, but am getting the 'object reference not set to an instance of an object'.

  I've also tried doing the following, but get the same error. I know it's simeple, but I can't for the life of me see what I doing wrong!
  

  object scalar = new object()

  scalar = command.ExecuteScalar()

  string result = Scalar.ToString();

  
  

• • Reply
  donpisci

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  176 Posts

  Re: Input string was not in a correct format.

  Jun 27, 2010 01:12 PM|donpisci|LINK

  I know you said it was bad, but I managed to get around the problem using a nested function and instead of having:

  'command.Parameter.Add'

  I've changed it to:

  'command.Parameter.AddWithValue'

  Thanks!
  

  
  

• • Reply
  SGWellens

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  Re: Input string was not in a correct format.

  Jun 27, 2010 06:32 PM|SGWellens|LINK

  Perhaps the function is returning null and it is being converted to zero.  You may still have a problem. 

  Steve Wellens
  
  My blog
  
• • Reply
  donpisci

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  176 Posts

  Re: Input string was not in a correct format.

  Jul 01, 2010 08:22 AM|donpisci|LINK

  Hi Steve,

  Sorry for not getting back sooner....you're right, it is returning null. Will have to re- write me thinks.