hi..
Datareader behavior is read-only, forward only & fetches record one by one. if u want only one select statement then u can use datareader otherwise dataadapter. if u'r connection string is sqlserver then
       SqlDataReader dr=cmd.ExecuteReader()

   GridView providea arrangement of data from dataset in a XML format
     
     GridView1.DataSource=<dataset object>.Tables["alias name of table in dataset"]
    GridView1.DataBind()