The code below produced the error: OUT or INOUT argument 3 for routine mysql.getAuthentication is not a variable or NEW pseudo-variable in BEFORE trigger. Did I miss something?.

using System;
using System.Data.Odbc;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using MySql.Data.MySqlClient;

public partial class _Default : System.Web.UI.Page 
{
    
    protected void Page_Load(object sender, EventArgs e)
    {
        string MyConString = "SERVER=localhost;" +
        "DATABASE=mysql;" +
        "UID=root;" +
        "PASSWORD=12345;";
        MySqlConnection connection = new MySqlConnection(MyConString);
        MySqlCommand command = new MySqlCommand("getAuthentication", connection);
        command.CommandType = CommandType.StoredProcedure;
        command.Parameters.Add(new MySqlParameter("uname", "admbsa1"));
        command.Parameters.Add(new MySqlParameter("pws", "$$!@!#*&"));
        command.Parameters.Add(new MySqlParameter("@total",SqlDbType.Int));
        command.Parameters.Add(new MySqlParameter("@pwsval",SqlDbType.VarChar));
        command.Parameters.Add(new MySqlParameter("@logId",SqlDbType.VarChar));
        command.Parameters.Add(new MySqlParameter("@grpname", SqlDbType.VarChar));
        command.Connection.Open();
        command.ExecuteNonQuery();
        command.Connection.Close();

        string t_return = command.Parameters["@total"].Value.ToString();
        Console.Write(t_return);
    }

    protected void GridView1_SelectedIndexChanged1(object sender, EventArgs e)
    {

    }
}

Correction: you don't need the braces.
Here is an example I just created:

using System;
using System.Collections.Generic;
//
using MySql.Data.MySqlClient;

/* // STORED PROCEDURE //
 create procedure GetWordsByLength(IN len INT)
BEGIN
	SELECT asdf.x
	FROM XXX.asdf
	WHERE (length(x)=len);
END 
*/
namespace DW_398532
{
   using DB_MyLister;
   public class DW_398532
   {
      private static int m_intLen = 3;

      public static bool Load(List<string> master, ref string strError)
      {
         bool blnRetVal = true;
         try
         {
            string strSQL = "call GetWordsByLength(@paramTargetLen)";
            using (MySqlConnection conn = new MySqlConnection(CDB_MyLister.csb.ToString()))
            {
               conn.Open();

               MySqlCommand cmd = new MySqlCommand(strSQL, conn);
               cmd.Parameters.Add("@paramTargetLen", MySqlDbType.Int16).Value = m_intLen;

               using (MySqlDataReader rdr = cmd.ExecuteReader())
               {
                  while (rdr.Read())
                  {
                     master.Add(rdr["x"].ToString().Trim());
                  }
                  //
                  rdr.Close();
               }

               conn.Close();
            }
         }
         catch (Exception exc)
         {
            blnRetVal = false;
            strError = exc.Message;
         }

         return blnRetVal;
      }

      static void Main(string[] args)
      {
         string strError = "";
         List<string> lst_str = new List<string>();
         if (!Load(lst_str, ref strError))
         {
            Console.WriteLine("Could not load: " + strError);
            return;
         }

         Console.WriteLine("Finished");
      }
   }
}

The table contains:
one
two
three
four
five
six
seven
eight
nine
ten

and the result of the query is:
one
two
six
ten

I made the changes but received the error: OUT or INOUT argument 3 for routine mysql.getAuthentication is not a variable or NEW pseudo-variable in BEFORE trigger.

using System;
using System.Data.Odbc;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using MySql.Data.MySqlClient;

public partial class _Default : System.Web.UI.Page 
{
    
    protected void Page_Load(object sender, EventArgs e)
    {
        /*string MyConString = "SERVER=localhost;" +
        "DATABASE=mysql;" +
        "UID=root;" +
        "PASSWORD=sumbat31;";
        MySqlConnection connection = new MySqlConnection(MyConString);
        MySqlCommand command = connection.CreateCommand();
        command.CommandText = "select * from corporate";
        connection.Open();
        MySqlDataAdapter myadapter = new MySqlDataAdapter(command);
        DataSet dts = new DataSet();
        myadapter.Fill(dts);
        dts.Tables[0].Columns[0].ColumnName = "ID";
        GridView1.DataSource = dts.Tables[0];
        GridView1.DataBind();
        connection.Close();*/

        string MyConString = "SERVER=localhost;" +
        "DATABASE=mysql;" +
        "UID=root;" +
        "PASSWORD=abcde;";
        MySqlConnection connection = new MySqlConnection(MyConString);
        MySqlCommand command = connection.CreateCommand();
        command.CommandText = "call getAuthentication(?param1,?param2,@total,@pwsval);";
        command.Parameters.AddWithValue("?param1", "admbsa1");
        command.Parameters.AddWithValue("?param2",null);
        command.Parameters.Add(new MySqlParameter("@total",SqlDbType.Int));
        command.Parameters.Add(new MySqlParameter("@pwsval",SqlDbType.VarChar));
        command.Connection.Open();
        command.ExecuteNonQuery();
        command.Connection.Close();

        string t_return = command.Parameters["@total"].Value.ToString();
        Console.Write(t_return);
    }

    protected void GridView1_SelectedIndexChanged1(object sender, EventArgs e)
    {

    }
}

Is there any reason you're mixing styles of parameter adds?
And shouldn't that SqlDbType be a MySqlDbType?

You could also try something like this (untested code):

protected void Page_Load(object sender, EventArgs e)
      {
         // Get this from elsewhere (like another DLL)
         MySqlConnectionStringBuilder csb = new MySqlConnectionStringBuilder()
         {
            Database = "mysql",
            Server = "localhost",
            UserID = "root",
            Password = "abcde",
         };

         string t_return = ""; // must return no matter what

         try
         {
            using (MySqlConnection connection = new MySqlConnection(csb.ToString()))
            {
               connection.Open(); // can open any time

               string strSQL = "call getAuthentication(@param1,@param2,@total,@pwsval);";
               MySqlCommand command = new MySqlCommand(strSQL, connection);
               //
               command.Parameters.Add("@param1", MySqlDbType.VarChar).Value = "admbsa1";
               command.Parameters.Add("@param2", MySqlDbType.VarChar).Value = DBNull.Value;
               command.Parameters.Add("@total", MySqlDbType.Int16);
               command.Parameters.Add("@pwsval", MySqlDbType.VarChar);
               command.ExecuteNonQuery();
               //
               t_return = command.Parameters["@total"].Value.ToString();

               connection.Close();
            }
         }
         catch (Exception exc)
         {
            t_return = exc.Message;
         }

         Console.Write(t_return);
      }

I made the changes and received the error OUT or INOUT argument 3 for routine mysql.getAuthentication is not a variable or NEW pseudo-variable in BEFORE trigger.

using System;
using System.Data.Odbc;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using MySql.Data.MySqlClient;

public partial class _Default : System.Web.UI.Page 
{
    
    protected void Page_Load(object sender, EventArgs e)
    {
        string MyConString = "SERVER=localhost;" +
        "DATABASE=mysql;" +
        "UID=root;" +
        "PASSWORD=abcde;";
        MySqlConnection connection = new MySqlConnection(MyConString);
        MySqlCommand command = connection.CreateCommand();
        command.CommandText = "call getAuthentication('admbsa1',null,@total,@pwsval);";
        command.Parameters.Add(new MySqlParameter("@total",MySqlDbType.Int64));
        command.Parameters.Add(new MySqlParameter("@pwsval",MySqlDbType.VarChar,20));
        command.Connection.Open();
        command.ExecuteNonQuery();
        command.Connection.Close();

        string t_return = command.Parameters["@total"].Value.ToString();
        Console.Write(t_return);
    }

    protected void GridView1_SelectedIndexChanged1(object sender, EventArgs e)
    {

    }
}
DELIMITER$$
CREATE PROCEDURE getAuthentication(IN uname varchar(12), IN pws VARCHAR(12), OUT total INT, OUT pwsval VARCHAR(12))
BEGIN
   IF(uname IS NOT NULL AND pws IS NOT NULL) THEN
     SELECT COUNT(id) INTO total FROM authentication WHERE loginId=uname and password=pws;
   END IF;
   IF(uname IS NOT NULL AND pws IS NULL) THEN
     SELECT COUNT(id) INTO total FROM authentication WHERE loginId=uname;
     SELECT password INTO pwsval FROM authentication WHERE loginId=uname;
   END IF;
END$$
DELIMITER;


call getAuthentication('admbsa1','$$!@!#*&',@total,@pwsval);
call getAuthentication('admbsa1',null,@total,@pwsval);
select @total as 'total';
select @pwsval as 'pws';
DELIMITER$$
CREATE PROCEDURE getAuthentication(IN uname varchar(12), IN pws VARCHAR(12), OUT total INT, OUT pwsval VARCHAR(12))
BEGIN
   IF(uname IS NOT NULL AND pws IS NOT NULL) THEN
     SELECT COUNT(id) INTO total FROM authentication WHERE loginId=uname and password=pws;
   END IF;
   IF(uname IS NOT NULL AND pws IS NULL) THEN
     SELECT COUNT(id) INTO total FROM authentication WHERE loginId=uname;
     SELECT password INTO pwsval FROM authentication WHERE loginId=uname;
   END IF;
END$$
DELIMITER;


call getAuthentication('admbsa1','$$!@!#*&',@total,@pwsval);
call getAuthentication('admbsa1',null,@total,@pwsval);
select @total as 'total';
select @pwsval as 'pws';

On this page, codegecko says

And it's fixed! Removed the IN and OUT specifications and for variables going OUT, simply passed a null value into the procedure.

I found the solution:

using System;
using System.Data.Odbc;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using MySql.Data.MySqlClient;

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string MyConString = "SERVER=localhost;" +
        "DATABASE=mysql;" +
        "UID=root;" +
        "PASSWORD=abcde;";
        MySqlConnection connection = new MySqlConnection(MyConString);
        MySqlCommand command = connection.CreateCommand();
        command.CommandType = CommandType.StoredProcedure;
        command.CommandText = "getAuthentication";
        command.Parameters.AddWithValue("uname", "admbsa1");
        command.Parameters.AddWithValue("pws", null);
        command.Parameters.Add(new MySqlParameter("@total", MySqlDbType.Int32));
        command.Parameters["@total"].Direction = ParameterDirection.Output;
        command.Parameters.Add(new MySqlParameter("@pwsval", MySqlDbType.VarChar, 12));
        command.Parameters["@pwsval"].Direction = ParameterDirection.Output;
        command.Connection.Open();
        command.ExecuteNonQuery();
        command.Connection.Close();

        string t_return = command.Parameters["@pwsval"].Value.ToString();
        TextBox1.Text = t_return;
    }

    protected void GridView1_SelectedIndexChanged1(object sender, EventArgs e)
    {

    }
}

You're correct. FANTASTIC!
I had gotten the call to not throw an exception, but had forgotten to pull the value FROM the parameter.

This works, too:

public static bool Load(string master, ref string strError)
      {
         bool blnRetVal = true;
         try
         {
            string strSQL = "xxx.GetFirstWordByLength";
            using (MySqlConnection conn = new MySqlConnection(CDB_MyLister.csb.ToString()))
            {
               conn.Open();
               MySqlCommand cmd = new MySqlCommand(strSQL, conn);
               cmd.CommandType = CommandType.StoredProcedure;
               cmd.Parameters.Add("@len", MySqlDbType.Int16).Value = m_intLen;
               cmd.Parameters["@len"].Direction = ParameterDirection.Input;
               cmd.Parameters.Add("@lastword", MySqlDbType.VarChar).Direction = ParameterDirection.Output;
               cmd.ExecuteNonQuery();

               //Console.WriteLine(cmd.Parameters["@lastword"].Value);
               master = cmd.Parameters["@lastword"].Value;
               conn.Close();
            }
         }
         catch (Exception exc)
         {
            blnRetVal = false;
            strError = exc.Message;
         }

         return blnRetVal;
      }

The magic being removing the parameters and any other decorators from the name of the stored procedure.
Only use the procedure name, but the addition of the CommandType.StoredProcedure; is essential.

Edited 5 Years Ago by thines01: fixed code

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