How to check if a datareader is closed or opened?

1 Answers  

---

How To Update A Column In A DataGrid Using C#.NET? I am getting InvalidCastException as (Specified cast is not valid) while updating 2nd column in a datagrid? Id,firstname,lastname are the three columns of my datagrid respectively. I wanted to edit the second column(lastname) and update it. I did the following code in DataGrid's updatecommand(),but failed to update ! Int varid=(int)DataGrid1.DataKeys[e.Item.ItemIndex]; TextBox lnm=(TextBox)e.Item.Cells[2].Controls[0]; string str=lnm.Text ; SqlCommand cmd=new SqlCommand("update customer set lastname='" + str + "' where id=" + varid + "",con); cmd.ExecuteNonQuery(); DataGrid1.EditItemIndex=- 1; DataGrid1.DataBind();

2 Answers   Mind Tree, TCS,

---

Explain the basic use of "dataview" and explain its methods.

0 Answers  

---

What?s the role of the DataReader class in ADO.NET connections?

7 Answers   Honeywell, Ksb,

---

What are the advantage of ado.net?

0 Answers  

---

What is the difference in record set and dataset?

0 Answers  

---

List the 4 common ado.net namespaces?

0 Answers  

---

Explain the different row versions available in table?

0 Answers  

---

Is it possible to load multiple tables in a Dataset?

0 Answers  

---

what is the syntax code to oledb to connect oracle

6 Answers   IBM,

---

What is the use of data grid?

0 Answers  

---

Why sql Data Reader object not created

9 Answers   Matrix,

---