Parameterize SQL query

Question

Many posts about Parameters in SQL with C# but I am still missing something. I am not getting an error message but no data is inserted. What is missing? I have text boxes na

Answer 1

You forgot to execute the command ;)

EDIT: you also didn't use the parameters that you created at the beginning of the method.

    ...
    try
    {
        conn.Open();
        //SqlTransaction trans = conn.BeginTransaction();
        //comm.Transaction = trans;
        comm.Parameters.Add(firstparam);
        comm.Parameters.Add(lastparam);
        comm.Parameters.Add(addressparam);
        comm.Parameters.Add(cityparam);
        comm.Parameters.Add(stateparam);
        comm.Parameters.Add(zipparam);

        // This is what you forgot:
        comm.ExecuteNonQuery();
    }
    ...

BTW, don't do things like that:

    catch (Exception ex1)
    {
        throw new Exception(ex1.ToString(), ex1);
    }

It's useless, it just adds a new level of exception without adding anything useful. Just let the exception bubble up the stack until it reaches a catch block that actually does something useful.