def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def stroke_rectangle(self, x, y, w, h):
		self.line(x,y,w,True)
		self.line(x,y+h-1,w,True)
		self.line(x,y,h,False)
		self.line(x+w-1,y,h,False)