insert value textbox into mysql database

I have problems inserting a textboxvalue into a mysql database - there's no errormessage and no inserting. What am I doing wrong

 private void RegisterCustomer()
    {
        string firstname = txtfirstname.ToString();

        OdbcConnection conn;
        conn = new OdbcConnection(ConfigurationManager.ConnectionStrings["jConnString"].ConnectionString);
        conn.Open();

        string sql = "insert into klant (firstname) values (@firstname)";
        OdbcCommand cmd = new OdbcCommand(sql, conn);
        cmd.Parameters.Add("@firstname", OdbcType.VarChar).Value = firstname;
      开发者_JAVA百科  try
        {
            cmd.ExecuteNonQuery();
        }
        catch (Exception ex)
        {
            Check.Text += ex.ToString() + sql;
        }
        finally
        {
            conn.Close();
            conn.Dispose();
            Check.Text += "OK";
        }
    }

According to MSDN.
http://msdn.microsoft.com/en-us/library/system.data.odbc.odbccommand.parameters.aspx

When CommandType is set to Text, the .NET Framework Data Provider for ODBC does not support passing named parameters to an SQL statement or to a stored procedure called by an OdbcCommand. In either of these cases, use the question mark (?) placeholder.

So your query should be:

string sql = "insert into klant (firstname) values (?)"

If you have multiple parameters, they are set in the order you add them.

In addition, I think the line

string firstname = txtfirstname.ToString();

should read

string firstname = txtfirstname.Text();

But that is not what is causing your immediate problem.

"insert into klant values (firstname) values (@firstname)"

I think the right query would be:

"insert into klant values (@firstname)";

Your query:

string sql = "insert into klant values (firstname) values (@firstname)";

Is specifying values twice. It should be in the form:

INSERT [LOW_PRIORITY | DELAYED | HIGH_PRIORITY] [IGNORE]
[INTO] tbl_name [(col_name,...)]
{VALUES | VALUE} ({expr | DEFAULT},...),(...),...
[ ON DUPLICATE KEY UPDATE
  col_name=expr
    [, col_name=expr] ... ]

So remove the extra values and you should be good.

You have values twice. I've never seen it that way. You INSERT INTO table (columm_names...) VALUES (value1, 'value2',...)

edit: maybe you should try straight text and eliminate the box to see if it enters. At least you'll know where to look.

edit: I'd also echo my firstname variable to see what it has.

More accurately, it should be:

insert into klant (firstname) values (@firstname)