private void SqlSelect(object sqlcommand)
        {
            int i = 0;
            foreach (var database in SelectedItem)
            {
                using (NpgsqlConnection connect = new NpgsqlConnection(connectionString + "Database=" + database))
                    try
                    {
                        connect.Open();
                        NpgsqlCommand command = new NpgsqlCommand(sqlcommand.ToString(), connect);
                        NpgsqlDataReader reader = command.ExecuteReader();
                        if (reader.HasRows)
                        {
                            if (Tselect == sampling)
                            {
                                listBox1.Invoke((MethodInvoker)(() => listBox1.Items.Add(database)));
                            }
                            else
                            {
                                while (i != reader.VisibleFieldCount)
                                {
                                    Invoke((MethodInvoker)delegate { dataGridView1.Columns.Add(reader.GetName(i), reader.GetName(i)); }, new object[] { });
                                    i++;
                                }
                                i = 0;
                                foreach (DbDataRecord datarecord in reader)
                                {
                                    Invoke((MethodInvoker)delegate { dataGridView1.Rows.Add(); }, new object[] { });
                                    for (int count = 0; count < reader.VisibleFieldCount; count++)
                                    {
                                        Invoke((MethodInvoker)delegate { dataGridView1.Rows[i].Cells[count].Value = datarecord[count].ToString(); }, new object[] { });
                                    }
                                    i++;
                                }
                            }
                        }
                        else
                        {
                            listBox2.Invoke((MethodInvoker)(() => listBox2.Items.Add(database)));
                        }
                    }
                    catch (NpgsqlException e)
                    {
                        ++id;
                        find_err_lbl.Text = string.Format("Ошибок: {0}", id);
                        find_err_lbl.ToolTipText += database + Environment.NewLine;
                    }
                    finally
                    {
                        connect.Close();
                    }
                Invoke((MethodInvoker)delegate { toolStripProgressBar1.Value++; }, new object[] { });
                Invoke(new SetToolStripDelegate(SetToolStrip), string.Format("Прогресс: {0}%", 100 * ++i / SelectedItem.Count));
            }
            execute.Invoke((MethodInvoker)(() => execute.Text = "Выполнить"));
            execute.Invoke((MethodInvoker)(() => execute.Click -= new EventHandler(secondAction)));
            execute.Invoke((MethodInvoker)(() => execute.Click += new EventHandler(firstAction)));
            Invoke(new SetToolStripDelegate(SetToolStrip), "Готово");
            _thread.ForEach(delegate (Thread thread)
            {
                thread.Abort();
            });
        }