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(); } } }

2704

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

1996

What is the meaning of lock escalation and why/how to stop this?

2704

IMP-00064: Definition of LOB was truncated by export

6464

IMP-00063: Warning: Skipping table "string"."string" because object type "string"."string" cannot be created or has different identifier

2777

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

3219

What is SCD (Slowly Changing Dimensions)? What are its types?

2714

What is the use of NOLOCK locking hint?

1829

How to resolve QSM-01108 error. I have no OR conditions in my query, but do have 9 IN conditions. The error says the max limit is 2 while I have 257 number of disjuncts. However, if I remove even a single IN condition, the query is rewritten. I cannot change my query. How can I resolve this issue?

2760

IMP-00070: Lob definitions in dump file are inconsistent with database.

1796

ORA-26029: index string.string partition string initially in unusable state

2223

When you get following error? Error 3154: The backup set holds a backup of a database other than the existing database.

2576

ORA-26027: unique index string.string partition string initially in unusable state

6785

ORA-26094: stream format error: input column overflow

2852

How to solve -805 error i.e. Bind issue. There are two conditions- 1) If you have access to the database table 2) If you don't have access to the table

2694