If a DataReader holds one record at a time, then why...

Question

My understanding is that a DataReader can only hold one record in memory at any given time and has to keep the connection to the database open to read subsequent records in a forward only manner. How is it then that I can bind a dataReader to a DataGrid and display multiple rows? I just don't get it. I currently have this code: DbDataReader ddr = GetMetaClasses(); GridView1.DataSource = ddr; GridView1.DataBind(); GetMetaClasses executes this stored procedure: SELECT * FROM MetaClasses; This is what my page displays: ID Name FriendlyName MetaClassType 1 NewsItems News Article 2 ClientPage Client Page Page I don't understand how binding to the dataReader would work successfully and show all the results from the query if a dataReader can only hold one record in memory. Can someone please explain?? Thanks in advance!

Niradhip Chakraborty · Answer

1) DataReader does not implement any specific interface so that it can be bindable 2) DataReader is for reading data.So if some how u r able to bind that,it won't allow u to edit that.So it's of no use. 3) DataReader is forward only,that means u can get a record at a time but can't traverse back to the prev record. This code shows how to bind gridview with data reader Use this code on page load void Page_Load(Object sender, EventArgs e) { String Q; Sql command cmd; Sql DataReader dr; SqlConnection conn = new SqlConnection(); conn.ConnectionString = ConfigurationManager.ConnectionStrings ["cn"].ConnectionString.ToString(); conn.Open(); Q = "select * from tablename"; cmd= New Sqlcommand(Q, conn); dr = cmd.ExecuteReader(); Gridview1.DataSource = dr; Gridview1.DataBind(); }

Kirtan Patel · Answer

When you bind Data reader to gridView it iterates through records one by one and All records Rendered One bye one in HTML Table row so as a result you see data in Grid View .