Артём Зубков

select a.id, a.name, count(b.id) from users a
left join articles b on b.user_id = a.id
group by a.id, a.name

вот как отрабатывает

Ответ на вопрос в предыдущем комментарии.

private static void InitConnectSetting() {
	Configuration config = ConfigurationManager.
		OpenExeConfiguration(ConfigurationUserLevel.None);

	var path = DebugMode ? DebugModeDbPath() : Application.StartupPath;
	
	Dictionary<string, string> db = new Dictionary<string, string>() {
		{"ec", string.Format("{0}\\db\\{1}", path, /*DebugMode ? "data.db" : */"data.db")},
	};

	var conSets = config.ConnectionStrings;

	foreach (var key in db.Keys) {
		var sName = key + "Entities";
		var conSet = conSets.ConnectionStrings[sName];
		if (conSet != null)
			conSets.ConnectionStrings.Remove(conSet);
		conSet = new ConnectionStringSettings();
		conSet.ProviderName = "System.Data.EntityClient";
		conSet.Name = sName;				
		conSet.ConnectionString = 
			string.Format("metadata=res://*/{0}Model.csdl|res://*/{0}Model.ssdl|res://*/{0}Model.msl;" + 
				"provider=System.Data.SQLite;" +
				"provider connection string=\"data source={1}\"", key, db[key]);
		conSets.ConnectionStrings.Add(conSet);
		var file = new FileInfo(db[key]);
		if (false && !file.Exists) {
			using (BinaryWriter binWriter =
						new BinaryWriter(File.Open(db[key], FileMode.Create))) {
				switch (key) {
					case "ec":
						binWriter.Write(Properties.Resources.kladr, 0, Properties.Resources.kladr.Length);
						break;							
				}
			}
		}
	}
	conSets.SectionInformation.ForceSave = true;
	conSets.SectionInformation.RequirePermission = false;
	config.Save(ConfigurationSaveMode.Modified);

	ConfigurationManager.RefreshSection(conSets.SectionInformation.Name);
}

UPD: При запуске предлагать выбрать бд а затем изменять строки подключения.