source cantain no data row while using take asp.net

Question

currently when the records are zero i am getting the error source cantain no data row to manage that i have checked it count>0 but still i am getting any idea how to solve this.

dynamic dt = ds.Tables(0);
int totalrowCount = dt.Rows.Count;


//dt.Rows.Count 
//dt.Select().Take(100)
// dt.Rows.Cast(Of System.Data.DataRow)().Take(100)
DataTable dt1 = default(DataTable);
if (totalrowCount > 0) {
    dt1 = dt.AsEnumerable().Take(100).CopyToDataTable();
} else {
    dt1 = dt.AsEnumerable().CopyToDataTable();
}

It's not clear what you expect the check to do - if there are no rows, then `dt.AsEnumerable().Take(100)` would return the same sequence as `dt.AsEnumerable()`. It doesn't help that we don't know *where* you're getting an error. If it's in a later piece of code which requires a non-empty `DataTable`, then you really need to think more carefully about what you want to happen when there simply *aren't* any rows. — Jon Skeet, Jun 06 '17 at 06:57
Right, `CopyToDataTable` is documented as failing when there are no rows. So maybe you need to find a different way of creating a `DataTable` in that case - maybe just use `dt1 = dt;`? — Jon Skeet, Jun 06 '17 at 07:04
ok i have used dt.clone and it's working !! thanks for the help @JonSkeet — , Jun 06 '17 at 07:09

score 1 · Accepted Answer · answered Jun 06 '17 at 07:14

As documented, CopyToDataTable() can't be called on an empty sequence of rows - presumably because then there's no schema information to include. Instead, if you know your original table is empty and you want a new table with the same schema, just clone it. So you'd have:

DataTable dt = ds.Tables(0);
DataTable newTable = dt.Rows.Count > 0
    ? dt.AsEnumerable().Take(100).CopyToDataTable() 
    : dt.Clone();

score -1 · Answer 2 · answered Jun 06 '17 at 07:00

-1

Check number of rows with the following;

if (ds.Tables.Count > 0 && ds.Tables[0] != null && ds.Tables[0].Rows.Count > 0)

however when row nubmer<=0

dt1 = dt.AsEnumerable().CopyToDataTable();

This line does not make sense. Do you need to fetch null rows?

answered Jun 06 '17 at 07:00

Zbidi

116
10

1

If there were no tables, the code would be failing elsewhere. The OP is successfully checking whether or not there are any rows. – Jon Skeet Jun 06 '17 at 07:04

source cantain no data row while using take asp.net

2 Answers2