where is the parameter coming from?

Question

I have this method

public DataTable getStudents(SqlCommand cmd)
{
string CS = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
using (SqlConnection con = new SqlConnection(CS))
{
SqlDataAdapter da = new SqlDataAdapter(cmd);

DataTable dt = new DataTable();
cmd.Connection = con;
da.Fill(dt);
return dt;
}

I am trying to get student information by id when they click on button.On button click i have this code

int id = Convert.ToInt32(txtId.Text);
SqlCommand cmd = new SqlCommand("select id, first_name,last_name,birthdate,gender,phone,address,picture from students where id = " + id);

DataTable dt =student.getStudents(cmd);

In objectdatasource control when i add this method on SELECT button it is asking me where you are getting cmd parameter from? I do not understand which one give ?

Thanks

Jignesh Kumar · Answer

Hi, Please change your method as below, public DataTable getStudents( int Id) { string CS = ConfigurationManager.ConnectionStrings[ "DBCS" ].ConnectionString; using (SqlConnection con = new SqlConnection(CS)) { SqlCommand cmd = new SqlCommand( "select id, first_name,last_name,birthdate,gender,phone,address,p icture from students where id = " + id); SqlDataAdapter da = new SqlDataAdapter(cmd); DataTable dt = new DataTable(); cmd.Connection = con; da.Fill(dt); return dt; } Call your method as below from click button, int id = Convert.ToInt32(txtId.Text); DataTable dt =student.getStudents(id);

entry level · Answer

This is webform application. If I change the method it won't be reusable. Thanks

Nitin Sontakke · Answer

There are quite a few approaches for getting data from SQL Server to the application. I sincerely believe that you are most probably mixing them incorrectly. If at all possible, please try to understand different approaches, and then stick to just one approach from start to finish. The approach wherein each layer is written separately and works independently is probably the best approach. Is this the Windows Forms desktop application?