Question

I just learn Visual Studio C# for 2 months. Recently, I write the code that can connect with Microsoft Access 2007 and it run smoothly (it can show data and can delete record as I expect) However, when I build the project, it still show data but cannot delete record.(it show error message box “Unhandled exception has occurred in your application. If you click Continue, the application will ignore this error and attempt to continue. If you click Quit, the application will close immediately”)
I don’t know what’s wrong with it. I try many ways for the solution but not yet succeed.
I upload the project to 4shared.com so please download by this link –>
http://www.4shared.com/zip/bxhZC3Wp/WindowsFormsApplication32.html?

After download, please open and try running the code (file name WindowsFormsApplication32)
you will see 3 textboxes, type 1 and click button1, it will show name in textbox2 and city in textbox3. Now click button2 to delete the record, you can see that it will delete the record successfully. Then, open the folder iii>Debug, install the program (file name iii),and open the program (may located at C:\Program Files (x86)\Default Company Name\iii). You can try the same way as when you run the code but after click button2 to delete the record, it will show messagebox error (please download the picture of the message error by this link –> http://www.4shared.com/photo/FgUODfoW/error_messagebox.html? )
Anyone please help me.

PS. This is how I Build the project.

1. Open Visual Studio2010 by Right Click and select ‘Run as
   administrator’.
2. Open my project
3. ‘File’ > ‘Add’ > ‘New Project’
4. In ‘Add New Project’ Window, select ‘Other Project Types’>’Setup and Deployment’> ‘Visual Studio Installer’ select ‘Setup Project’
5. In ‘File System’ tab, right click ‘Application Folder’> ‘Add’ > ‘Project Output…’
6. In ‘File System’ tab, right click ‘Application Folder’> ‘Add’ > ‘File…’ and select my Microsoft Access 2007’s file.
7. in ‘Solution Explorer’ window, right click my project and select ‘Build’
   Is this way can import the database to my project correctly?

Below is the code.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;

namespace WindowsFormsApplication32
{
public partial class Form1 : Form
  {
    public Form1()
    {
        InitializeComponent();
    }
    private OleDbConnection connection;
    private OleDbDataAdapter adapter;

    private OleDbCommand command;
    private string sql;

    private void Form1_Load(object sender, EventArgs e)
    {
        string con = @"Provider=Microsoft.ACE.OLEDB.12.0;
                        Data Source=|DataDirectory|\bbb.accdb;
                        Persist Security Info=False;";
        connection = new OleDbConnection(con);
        if (connection.State == ConnectionState.Closed)
            connection.Open();
    }

    private void button1_Click(object sender, EventArgs e)
    {

        sql = "SELECT * FROM test WHERE id=" + textBox1.Text;

        command = new OleDbCommand(sql, connection);

        adapter = new OleDbDataAdapter(command);
        DataSet data = new DataSet();
        adapter.Fill(data, "abc");
        if (data.Tables["abc"].Rows.Count == 0) return;

        else
        {

            textBox2.Text = Convert.ToString(data.Tables["abc"].Rows[0]["Name"]);
            textBox3.Text = Convert.ToString(data.Tables["abc"].Rows[0]["City"]);
        }


    }

    private void button2_Click(object sender, EventArgs e)
    {
        DialogResult result = MessageBox.Show("are you sure to delete", "delete", MessageBoxButtons.OKCancel);
        if (result == DialogResult.Cancel) return;
        sql = "DELETE FROM test WHERE ID=" + textBox1.Text;
        command = new OleDbCommand(sql, connection);
        int r = (int)command.ExecuteNonQuery();
        if (r > 0)
        {
            MessageBox.Show("already delete");
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
        }
        else MessageBox.Show("error to delete");


        }
    }
}

Answer 1

The error is because of the folder permissions. If you are using Window 7, after you installed the application, go to the installed directory and right click on the executable. Click on “Run as administrator” and now try deleting the record. This time it will be successful.

Alternate method to work in any OS
Provide modify permission to local system Users (MYPC\Users) and try again. It will work.