private void cboDb_SelectedIndexChanged(object sender, EventArgs e) { if (cboDb.SelectedIndex > 0) { var id = (int)cboDb.SelectedValue; var conn = _proj.ProjectDatabases.Where(d => d.ProjectDatabaeId == id).First(); DBWorker worker = new DBWorker(); var entityList = worker.GetEntitiesFromDatabase(conn); // exclude entities already in the system List <string> nameList = _proj.Entities.Select(a => a.EntityName).ToList(); var list = entityList.Where(a => !nameList.Contains(a.EntityName)).ToList(); entityBindingSource.DataSource = list; // select all entities SelectRows(true); } }