Primary key duplication ? using ADO.net

hi,

you have to put Indentity to Id column in database so it will increment automatically no need to insert it from front end .

1st make the Studentid column to identity and primary key

then try this code:

  protected void Button7_Click(object sender, EventArgs e)
  {
 
 
  cmd.CommandText = string.Format("insert into studentform(studentname,emailid,contactno,course,level,semister,username,password) values({0},'{1}','{2}',{3},{4},{5},{6},'{7}')", TextBox2.Text, TextBox3.Text, TextBox4.Text, TextBox5.Text, TextBox6.Text, TextBox7.Text, TextBox8.Text, TextBox9.Text);
  con.Open();
  int count = cmd.ExecuteNonQuery();
  Response.Write("ssss" + count);
  con.Close();
  }