cur.execute("UPDATE BD SET test1 = ? WHERE test2 = ?", (0, "123"))

import sys
from PyQt5.QtWidgets import QApplication, QWidget
from PyQt5.QtGui import QIcon

class Example(QWidget):
	def __init__(self):
		super().__init__()
		self.initUI()
		self.myclose = False # myclose = True - закроете X

	def initUI(self):
		self.setGeometry(300, 300, 300, 220)
		self.setWindowTitle('Icon')
		self.show()

	def closeEvent(self,event):
		if self.myclose:
			print("Закрылось")
		else:
			event.ignore()
			print("Не закрывается")

if __name__ == '__main__':
	app = QApplication(sys.argv)
	ex = Example()
	sys.exit(app.exec_())