title: Insert, Delete or Update cannot be performed?
body: <p><strong>My query seems to be correct but why is this happening?</strong></p>
  
  <p><img src="https://i.stack.imgur.com/4rDwP.jpg" alt="enter image description here"></p>
  
  <pre><code>        OleDbConnection con = new OleDbConnection();
  
          con.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\Sparrow vivek\Documents\Billing.accdb";
          con.Open();
          DateTime a = Convert.ToDateTime(label2.Text);
          String query = "INSERT INTO balancesheet (BillNumber,CusName,Date,Amount) values (?,?,?,?)";
          OleDbCommand cmd = new OleDbCommand(query, con);
          cmd.Parameters.AddWithValue("?",label3.Text);
          cmd.Parameters.AddWithValue("?", label4.Text);
          cmd.Parameters.AddWithValue("?", a.ToString("yyyy-MM-dd"));
          cmd.Parameters.AddWithValue("?", label6.Text);
          cmd.ExecuteNonQuery();
          con.Close();
  </code></pre>