Error With Dynamically Created SQL Insert statement
cmd.CommandText = "INSERT INTO LogIn(Username,Password) VALUES('" + AddUsernameTextBox.Text + "','" + AddPasswordTextBox.Text + "')";

cmd.CommandText = "INSERT INTO LogIn([Username],[Password]) VALUES('" + AddUsernameTextBox.Text + "','" + AddPasswordTextBox.Text + "')";

command.CommandText = "INSERT INTO Login([Username],[Password]) VALUES(@Username, @Password)";

  //Not sure how you create your commands in your project
  //here I'm using the ProviderFactory to create instances of provider specific DbCommands.

  var parameter = dbProviderFactory.CreateParameter();
  parameter.DbType = System.Data.DbType.String;
  parameter.ParameterName = "@Username";
  parameter.Value = AddUsernameTextBox.Text;
  command.Parameters.Add(parameter);

  parameter = dbProviderFactory.CreateParameter();
  parameter.DbType = System.Data.DbType.String;
  parameter.ParameterName = "@Password";
  parameter.Value = AddPasswordTextBox.Text;
  command.Parameters.Add(parameter);

ConnectionStringSettings connectionStringSettings = ConfigurationManager.ConnectionStrings["SomeConnectionName"];
  if (connectionStringSettings == null)
    throw new Exception("Application config file does not contain a connectionStrings section with a connection called "SomeConnectionName"");
  DbProviderFactory dbProviderFactory = DbProviderFactories.GetFactory(connectionStringSettings.ProviderName);
  using (var dbConnection = dbProviderFactory.CreateConnection())
  {
    dbConnection.ConnectionString = connectionStringSettings.ConnectionString;
    dbConnection.Open();
    using (var command = dbConnection.CreateCommand())
    {
      command.CommandText = "INSERT INTO Login([Username],[Password]) VALUES(@Username, @Password)";

      var parameter = dbProviderFactory.CreateParameter();
      parameter.DbType = System.Data.DbType.String;
      parameter.ParameterName = "@Username";
      parameter.Value = AddUsernameTextBox.Text;
      command.Parameters.Add(parameter);

      parameter = dbProviderFactory.CreateParameter();
      parameter.DbType = System.Data.DbType.String;
      parameter.ParameterName = "@Password";
      parameter.Value = AddPasswordTextBox.Text;
      command.Parameters.Add(parameter);

      var dbTransaction = dbConnection.BeginTransaction();
      try
      {
        command.ExecuteNonQuery();
        dbTransaction.Commit();
      }
      catch (Exception)
      {
        dbTransaction.Rollback();
        throw;
      }
    }
  }

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <connectionStrings>
    <add name="SomeConnectionName" providerName="System.Data.OleDb" connectionString="Your Provider Specific Connection String" />
  </connectionStrings>
</configuration>

using (var con = new OleDbConnection(_constring))
            {
                con.Open();
                using (
                    var cmd =
                        new OleDbCommand(
"UPDATE LogIn SET Username=@Username, Password=@Password WHERE (ID = @Id)",
                            con))
                {
                    try
                    {

                        cmd.Parameters.AddWithValue("@Username",EditUsernameTextBox.Text);
                        cmd.Parameters.AddWithValue("@Password",EditPasswordTextBox.Text);
                        cmd.Parameters.AddWithValue("@Id",IDTextBox.Text);


                        cmd.ExecuteNonQuery();
                    }
                    catch (Exception ex)
                    {
                        throw;
                    }
                    finally
                    {
                        con.Close();
                    }

                }

' ; DROP TABLE login

"UPDATE
    LogIn
SET
    Username = '" + EditUsernameTextBox.Text + "'
    ,Password = '" + EditPasswordTextBox.Text + "'
WHERE
    (ID = '" + IDTextBox.Text + "')";

WHERE (ID ='" + IDTextBox.Text + "')";