Filling an arraylist from a datareader

I have a problem with how to fill an array list from a data reader

string queryDTL = " SELECT * FROM tbl1  ";                 

connection.Connect();
cmd = new OracleCommand(queryDTL, connection.getConnection());
dr_DTL = qcmd2.ExecuteReader();

ArrayList RecordsInfo = new ArrayList();
while (dr_DTL.Read())
{
    RecordsInfo = dr_DTL["number"].ToString();
}   

The problem is the datareader contain alot of info other than the number but I don't know how to put them in their correct position.

I am still a beginner in this开发者_Python百科 sorry if it sounds stupid.

You can't put a String in an ArrayList. You have to add the string to the list. Ex. :

ArrayList RecordsInfo = new ArrayList();   
while (dr_DTL.Read())   
{
       RecordsInfo.Add(dr_DTL["number"].ToString());   
}      

If you want a list of String the best way is using List<String>. Ex. :

List<String> RecordsInfo = new List<String>(); 
while (dr_DTL.Read()) 
{    
    RecordsInfo.Add(dr_DTL["number"].ToString()); 
}    

I think you would be better off with a DataTable and an adapter:

    SqlConnection Conn = new SqlConnection(MyConnectionString);
    Conn.Open();

    SqlDataAdapter Adapter = new SqlDataAdapter("Select * from Employees", Conn);

    DataTable Employees = new DataTable();

    Adapter.Fill(Employees);

    GridView1.DataSource = Employees;
    GridView1.DataBind();

Of course in your case, use the Oracle versions of the objects.

Hi you have to do RecordInfo.Add, currently you are reassigning the whole arraylist...

Also if you are retrieving too many columns, just query the columns you need, in your case number, not simply SELECT * ...