Dataaccess help in three tier asp.net architecture - asp.net

Question

I have DAL function as
public DataTable executeSelectQuery(String _query, SqlParameter[] sqlParameter)
{
SqlCommand myCommand = new SqlCommand();
DataTable dataTable = new DataTable();
dataTable = null;
DataSet ds = new DataSet();
try
{
myCommand.Connection = openConnection();
myCommand.CommandText = _query;
myCommand.Parameters.AddRange(sqlParameter);
myCommand.ExecuteNonQuery();
myAdapter.SelectCommand = myCommand;
myAdapter.Fill(ds);
dataTable = ds.Tables[0];
}
catch (SqlException e)
{
Console.Write("Error - Connection.executeSelectQuery - Query:
" + _query + " \nException: " + e.StackTrace.ToString());
return null;
}
finally
{
}
return dataTable;
}
My button click
public void save_click(object sender,EventArgs e)
{
try
{
string query = "Insert into customer_master(customer_title,customer_name)values(#parameter1,#parameter2)";
SqlParameter[] sqlparam = new SqlParameter[2];
sqlparam[0] = new SqlParameter("#parameter1", SqlDbType.VarChar, 50);
sqlparam[0].Value = ddl_title.SelectedValue;
sqlparam[1] = new SqlParameter("#parameter2", SqlDbType.VarChar, 50);
sqlparam[1].Value = txt_group_name.Text;
string id = ms.insert(query, sqlparam);
catch(Exception ex)
{
throw ex;
}
}
I want the button click function values to passed not as sqlparameter but as sql command object.How to do this with sqlcommand object instead of sqlparameter.

Answer 1

Why do you want to pass around SqlCommand objects?? I wouldn't consider that an improvement of your current code - in the contrary!
Your UI code should really only pass values to the DAL function - just a List<int> or two strings or something. The DAL should do all the database-related stuff like creating SqlCommand and SqlParameters
So in your case here, I would have a method InsertCustomer on your DAL something like this:
public void InsertCustomer(string customerName, string customerTitle)
{
.... // do all the DB stuff here - create SqlCommand, fill in SqlParameter,
// execute the query
}
and your UI code should call this like this:
MyDAL dal = new MyDAL();
dal.InsertCustomer(txt_group_name.Text, ddl_title.SelectedValue);
There should be no trace whatsoever of ADO.NET classes or function in your UI code layer! So don't create SqlCommand or even SqlParameter in your UI layer - encapsulate this in the DAL layer! That what it's for!