I have written the code as below. here problem is that dt remain null. how to solve thst please tell me. public partial class Form1 : Form { private DataTable DTable; private DataRow drow; public Form1() { InitializeComponent(); } private OleDbConnection getConnection() { OleDbConnection con=new OleDbConnection (@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Documents and Settings\Administrator\My Documents\Visual Studio 2008\Projects\winApp for Student\winApp for Student\App_Data\SchooMgnSystem.mdb;Persist Security Info=True"); return con; } private void button1_Click(object sender, EventArgs e) { InsertData(); } private void InsertData() { if (DTable==null) { DTable = new DataTable(); DTable.Columns.Add("StudID", typeof(string)); DTable.Columns.Add("StudName", typeof (string)); DTable.Columns.Add("Address", typeof(string)); drow = DTable.NewRow(); drow[0] = txtStudID.Text; drow[1] = txtSTudName.Text; drow[2] = txtAddress.Text; DTable.Rows.Add(drow); grdStudent.DataSource = DTable; } else { drow = DTable.NewRow(); drow[0] = txtStudID.Text; drow[1] = txtSTudName.Text; drow[2] = txtAddress.Text; DTable.Rows.Add(drow); grdStudent.DataSource = DTable; } } private void button2_Click(object sender, EventArgs e) { string cmdstr; OleDbCommand cmd; OleDbConnection con = getConnection(); foreach (DataRow Drow in DTable.Rows) { cmdstr = "Insert into Student values('" + drow[0].ToString() + "','" + drow[1].ToString() + "','"+drow [2].ToString()+"')"; cmd = new OleDbCommand(cmdstr,con); try { con.Open(); cmd.ExecuteNonQuery(); } catch (Exception ex) { MessageBox.Show(ex.Message); } finally { con.Close(); } } }

2597

today's peformance is less than yesturday.it took 1 mint and today's performance is 7 mints.guys can anyone answer to mu question in sql

2405

How to view the error log for any specific instance?

2429

hi. i m Anil patel when reconcile 57f4 chalan(subcontraction with out excise)i m facing error like short by material 220 kg. even i have migo all material.

2499

i have created ODBC through Data sources and tests completed sucessfully. when i am Trying to connect SQL Server through ODBC (ODBC :Oracle Open Client Adapter for ODBC 2.0.2.15.0 Microsoft SQL Server 09.00.3054) unable to Connect to SQL*Plus: Release 8.0.4.0.0. it is given following error-message . Error: ORA-03121: NO interface driver connected- function not performed.

2756

What is the use of NOLOCK locking hint?

1723

ORA-26095: unprocessed stream data exists

3517

When i am connect database through toad,one error occured. ORA-12514: TNS:listener does not currently know of service requested in connect descriptor. plz help me thanks advance.............

2755

[ERROR] [main 11:01:20] (JCLLoggerAdapter.java:error:454) Unsuccessful: alter table user.CEN_USER_MASTER add constraint FKF4EDEDC3D0BAAE75 foreign key (ROLE_ID) references user.CEN_ROLE_MASTER [ERROR] [main 11:01:20] (JCLLoggerAdapter.java:error:454) ORA-02275: such a referential constraint already exists in the table

2683

IMG-02003: 2FF03 - incorrect color histogram feature specification

1663

IMP-00060: Warning: Skipping table "string"."string" because object type "string"."string" does not exist or has different identifier

3110

What severity level errors are managed in TRY-CATCH block?

2176

In my project I am using star schema and only diimension tables are loaded and not fact tables any one can help me why it is happening? Plase guide me.

2817

what is the instrument that used in Mechanical Energy??

2632

ORA-26079: file "string" is not part of table string.string

1902