The other day I found that there is a ​​.NET wrapper​​​ for ​​sqlite​​. sqlite is a very cool embeddable SQL-92 database engine. It's a single library that gives you a very fast, very scalable (2TB), single file, multi-user database. I thought the .NET wrapper is exceptionally handy because ADO is slow, and is hard to use (compared to this) and a HUGE overkill for smaller apps. It lets smaller apps have a real relational database without huge numbers of dependencies, complicated installs, or the complexity of ADO. Here is a really quick example program I wrote to try it out:

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using SQLite.NET;

namespace WindowsApplication2
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.ListBox listBox1;
private System.ComponentModel.Container components = null;
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.Button button1;
private SQLiteClient db;

public Form1()
{
db = new SQLiteClient("test.db");
InitializeComponent();
UpdateList();
}

public void UpdateList()
{
SQLiteResultSet results;

results = db.Execute("select name, phone from people order by name;");
listBox1.Items.Clear();
foreach(ArrayList row in results.Rows)
{
listBox1.Items.Add(row[0]);
}
}

protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}

#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.listBox1 = new System.Windows.Forms.ListBox();
this.textBox1 = new System.Windows.Forms.TextBox();
this.button1 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// listBox1
//
this.listBox1.Location = new System.Drawing.Point(8, 8);
this.listBox1.Name = "listBox1";
this.listBox1.Size = new System.Drawing.Size(136, 199);
this.listBox1.TabIndex = 0;
//
// textBox1
//
this.textBox1.Location = new System.Drawing.Point(192, 24);
this.textBox1.Name = "textBox1";
this.textBox1.Size = new System.Drawing.Size(120, 20);
this.textBox1.TabIndex = 1;
this.textBox1.Text = "textBox1";
//
// button1
//
this.button1.Location = new System.Drawing.Point(320, 24);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(72, 16);
this.button1.TabIndex = 2;
this.button1.Text = "button1";
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(408, 349);
this.Controls.Add(this.button1);
this.Controls.Add(this.textBox1);
this.Controls.Add(this.listBox1);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);

}
#endregion

/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}

private void button1_Click(object sender, System.EventArgs e)
{
db.Execute("insert into people values ('" + textBox1.Text.Replace("'","''") + "','111');");
UpdateList();
}
}
}
http://jclement.ca/devel/dotnet/sqlite.html

Using sqlite with .NET_.net