SqlDataReader

Question

User-797751191 posted

Hi

  I want sdr.read() should be executed if there is record else it should give message

using (SqlDataReader sdr = cmd.ExecuteReader())
                {
                    sdr.Read();
                    txtStoreAddress.Text = sdr["Address0"].ToString() + " " + sdr["Address1"].ToString();
                    txtStoreCity.Text = sdr["City"].ToString();
                    txtStorePostCode.Text = sdr["PostCode"].ToString();
                }

Thanks

Answer 1

User-821857111 posted

using (SqlDataReader sdr = cmd.ExecuteReader())
{
    if(sdr.HasRows)
    {
        sdr.Read();
	txtStoreAddress.Text = sdr["Address0"].ToString() + " " + sdr["Address1"].ToString();
	txtStoreCity.Text = sdr["City"].ToString();
	txtStorePostCode.Text = sdr["PostCode"].ToString();
    }
    else
    {
        // no records
    }
}

https://docs.microsoft.com/en-us/dotnet/api/system.data.sqlclient.sqldatareader.hasrows?view=netframework-4.8

Answer 2

User753101303 posted

Hi,

You can use https://docs.microsoft.com/en-us/dotnet/api/system.data.sqlclient.sqldatareader.hasrows?view=netframework-4.8 to test if a DataReader returned at least one row :

using (SqlDataReader sdr = cmd.ExecuteReader())
{
   if (sdr.HasRows())
   {
      sdr.Read();
      txtStoreAddress.Text = sdr["Address0"].ToString() + " " + sdr["Address1"].ToString();
      txtStoreCity.Text = sdr["City"].ToString();
      txtStorePostCode.Text = sdr["PostCode"].ToString();
   }

   else // Whatever
}

Not directly related but if using Web Forms 4.5 or later I would suggest to have a look at https://docs.microsoft.com/en-us/aspnet/web-forms/overview/presenting-and-managing-data/model-binding/retrieving-data. 

Answer 3

User-797751191 posted

Hi

  It is giving me below error

Error 54 Non-invocable member 'System.Data.Common.DbDataReader.HasRows' cannot be used like a method. 

Thanks

Answer 4

User-821857111 posted

HasRows is a property, not a method. Remove the () after it: HasRows, not HasRows()

Answer 5

User-797751191 posted

Hi

   It is showing HasRows = true but still it is giving error Invalid attempt to read when no data is present

using (SqlDataReader sdr = cmd.ExecuteReader())
            {
                if (sdr.HasRows)
                {
                    Session["InvoiceNo"] = sdr["InvoiceNo"].ToString();
}
}

Thanks

Answer 6

User-797751191 posted

sdr.read was not written

Thanks