Select SQL Server table data using ASP.NET - asp.net

Question

I want to select/retrieve all data from SQL Server using ASP.NET.
I've tried this code...
SqlCommand cmdd = new SqlCommand("select * from comment where ID='" + st + "'", con);
SqlDataReader drr;
drr = cmdd.ExecuteReader();
while(drr.Read())
{
user_name.Text = drr["Username"].ToString();
date.Text = drr["Date_Created"].ToString();
userrcomment.Text = drr["Comment"].ToString();
}
The code works fine but it can select only one record from database but I want to select all the records...
Also can any one tell me that how to use two/multiple queries using only one data reader....
Any help will be appreciated...
Update: problem is when the query run then only the last record will show, but I want that all the record will show against the mentioned id...
Update 2 this is my page code, as I am new in asp.net, so how can I get the username and other data in span or p tag...
<asp:Panel ID="Panel1" runat="server" Height="140px" Width="378px">
<p>
<asp:Label ID="user_name" runat="server"></asp:Label> Commented on <asp:Label ID="date" runat="server"></asp:Label></p>
<asp:Label ID="userrcomment" runat="server" Height="31px" Width="378px"></asp:Label>
</asp:Panel>

Answer 1

If you are getting only one records then there are two possibilities.
"select * from comment where ID='" + st + "'" In your where condition satisfy for only one record.
You are using SqlDataReader in while loop if there are many records you got but you can only see last record bcoz it will be overwrite last record in every loop.
while(drr.Read())
{
user_name.Text = drr["Username"].ToString();
date.Text = drr["Date_Created"].ToString();
userrcomment.Text = drr["Comment"].ToString();
}
the user_name.Text will replaced with last record.

Answer 2

Assuming your code is otherwise working, and you want to see all the data in just the three text boxes instead of some more tabular format.
SqlCommand cmdd = new SqlCommand("select * from comment where ID='" + st + "'", con);
SqlDataReader drr;
drr = cmdd.ExecuteReader();
while(drr.Read())
{
user_name.Text += drr["Username"].ToString();
date.Text += drr["Date_Created"].ToString();
userrcomment.Text += drr["Comment"].ToString();
}
Notice instead of overwriting the value of the textbox, I'm appending strings to it because I used +=. You might want to concatenate a , to it also.
More likely with multiple records though, you want to have them get in a table. The easiest and most straightforward way to do this is:
Code Behind
var cmd = new SqlCommand("select * from comment where ID=#id");
cmd.Parameters.AddWithValue("id", st);
var dt = new DataTable();
using(var con = new SqlConnection(connectionString))
{
con.Open();
dt.Load(cmd.ExecuteReader());
}
GridView1.DataSource = dt;
GridView1.DataBind();
Markup
<asp:GridView runat="server" id="GridView1" AutoGenerateColumns="true" />

Answer 3

You can execute multiple select queries using a single DataReader. There is an article namely,"Executing multiple SQL statements as one against SQL Server" in CodeProject. Please read it, you will get solution for sure.
using(SqlConnection conn=new SqlConnetion(ConnectionString))
{
using(SqlCommand cmdd = new SqlCommand("select * from comment where ID='" + st + "'", con))
{
using(SqlDataAdapter adapter=new SqlDataAdapter(cmdd))
{
DataTable dt=new DataTable();
adapter.Fill(dt);
//Bind the datasource with a repeater control in which you can place textbox control. It will repeat for every data rows.
}
}
}

Answer 4

You need to place the record into a dataset for you to get all the data you're trying to Retrieve
SqlCommand cmdd = new SqlCommand("select * from comment where ID='" + st + "'", con);
SqlDataReader drr = new SqlDataReader(cmdd);
DataSet ds = new DataSet();
da.Fill(ds);
foreach(DataRow dr in ds.Tables[0].Rows)
{
user_name.Text = dr["Username"].ToString();
date.Text = dr["Date_Created"].ToString();
userrcomment.Text = dr["Comment"].ToString();
}

Answer 5

select/retrieve all data from SQL-Server using ASP.NET
using this SqlDataReader (sqldr) GetValue for all the records
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionStringsName"].ConnectionString);
string sql = "select * from comment where ID='" + st + "'";
con.Open();
SqlCommand cmd = new SqlCommand(sql, con);
SqlDataReader sqldr = cmd.ExecuteReader();
if (sqldr.Read() == true)
{
user_name.Text = sqldr.GetValue(2).ToString();
date.Text = sqldr.GetValue(3).ToString();
userrcomment.Text = sqldr.GetValue(4).ToString();
}
sqldr.Close();
con.Close();