How to Check whether data is present or not in SQLDataReader

Question

Hi All,

I have DataReader with some sample data.
I need to check that whether data is present or not

i used following statement to check that

if((oDR["Team_AppRate"]!= null))

_iCount++;

So my requirement is i need to check whether data is present or not in Team_AppRate column in the database

but i got the following error

Invalid attempt to read when no data is present

How can i check that whether data is present or not in that column in database

Krishna Garad · Answer

try it using if(dr.HasRow) { if(dr["Column"]!=DbNull.Value) { // } }

Satyapriya Nayak · Answer

Hi Siva, Try this... using System; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.Data.SqlClient; public partial class _Default : System.Web.UI.Page { string connStr = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString; SqlCommand com ; string str ; protected void Button1_Click(object sender, EventArgs e) { SqlConnection con = new SqlConnection(connStr); con.Open(); str = "select count(*)from employee"; com = new SqlCommand(str, con); int count = Convert.ToInt32(com.ExecuteScalar()); if (count > 0) { lblMessage.Text = "Records present"; } else { lblMessage.Text = "Records Not present"; } } } Thanks

Krishna Garad · Answer

try in this way if (dr.HasRows) { if (dr.Read()) { if (dr["ColumnName"] is DBNull) { Response.Write("Value Is Null"); } else { Response.Write(dr["ColumnName"].ToString()); } } }

SIVA · Answer

Hi Krishna, again it showing the following exception. Invalid attempt to read when no data is present.

Mukesh Kumar · Answer

Hi, Try this while (reader.HasRows) { Console.WriteLine("	{0}	{1}", reader.GetName(0), reader.GetName(1)); while (reader.Read()) { Console.WriteLine("	{0}	{1}", reader.GetInt32(0), reader.GetString(1)); } reader.NextResult(); }

Muralidharan Deenathayalan · Answer

You can check like this... if(datareader.HasRows) { process the record here... } http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqldatareader.hasrows.aspx http://msdn.microsoft.com/en-us/library/haa3afyz(v=vs.80).aspx Hope this helps you.