我想将社会维护账单存储在每个用户数据节点中。所以我可以根据需要访问它们。我想用新记录更新已存在的记录，但我不知道如果firebase生成随机密钥，我如何获得特定记录。在这里，我评论了推送数据的行。我将如何以from Tkinter import *
from pymodbus.client.sync import ModbusTcpClient as ModbusClient
import time
import datetime
import RPi.GPIO as GPIO
import MySQLdb
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(0)
#-------------------------------------------------------GPIO
GPIO.setup(21, GPIO.OUT)#red led
GPIO.setup(20, GPIO.OUT)#yellow led
GPIO.setup(16, GPIO.OUT)#green led
GPIO.output(21, GPIO.HIGH)
GPIO.output(20, GPIO.HIGH)
GPIO.output(16, GPIO.HIGH)
#-------------------------------------------------------GPIO
class Screen(Frame):
def __init__(self, master):
Frame.__init__(self, master)
#-------------------------------------------------------Main
self.lbttn_clicks = 0
self.start_button()
self.material_button()
self.receive_button()
self.emergency_button()
self.lap_button()
self.finish_button()
self.minutes = 0
self.seconds = 0
#-------------------------------------------------------Modbus Var
self.LedRed_State = False
self.LedYellow_State = False
self.LedGreen_State = False
self.db = MySQLdb.connect("localhost","root","raspberry","DB_ASSY")
self.sql = "INSERT INTO Table_Assembly (Finished Product, Lap Time) VALUES (%s, %s)"
self.c= self.db.cursor()
self.client = ModbusClient('192.168.4.166')
self.client.connect()
print "ModbusClient connected..."
#-------------------------------------------------------Modbus Var
self.time_start = time.time()
self.pack(fill=BOTH, expand=1)
#-------------------------------------------------------Main
#-------------------------------------------------------Stopwatch
self._start = 0.0
self._elapsedtime = 0.0
self._running = 0
self.timestr = StringVar()
# self.makeWidgets()
#-------------------------------------------------------Stopwatch
#--------------------------------------------------------------------Main funcs
def start_button(self):
self.gbttn = Button(self)
self.gbttn['text'] = "Start"
self.gbttn['command'] = lambda: [ f() for f in [self.Start,
self.LedGreen, self.LedYellowOff, self.LedRedOff]]
self.gbttn.place(x = 100, y = 0)
def material_button(self):
self.ybttn = Button(self)
self.ybttn['text'] = "Request Material"
self.ybttn['command'] = self.LedYellow
self.ybttn.place(x=100, y=50)
def receive_button(self):
self.rbttn = Button(self)
self.rbttn ['text'] = "Receive Material"
self.rbttn ['command'] = self.LedYellowOff
self.rbttn.place(x=100, y=100)
def emergency_button(self):
self.ebttn = Button(self)
self.ebttn['text'] = "Emergency"
self.ebttn['command'] = lambda: [f() for f in [self.LedRed, self.LedYellowOff, self.LedGreenOff]]
self.ebttn.place(x=100,y=150)
def lap_button(self):
self.lbttn = Button(self)
self.lbttn['text'] = "Lap"
self.lbttn['command'] = lambda: [ f() for f in [self.lap_count, self.Start, self.insert_to_db]]
self.lbttn.place(x=100,y=200)
def finish_button(self):
self.fbttn = Button(self)
self.fbttn['text'] = "Finish"
self.fbttn['command'] = lambda: [f() for f in [self.Finish, self.Stop, self.Reset]]
self.fbttn.place(x=100, y=250)
def lap_count(self):
self.lbttn_clicks += 1
print str(self.lbttn_clicks)
# def stop_watch(self):
# print self.seconds
# time.sleep(1)
# self.seconds = int(time.time() - self.time_start)
#--------------------------------------------------------------------------------------Main funcs
#--------------------------------------------------------------------------------------Modbus funcs
#--------------------------------------------------------------------------------------Modbus funcs
#--------------------------------------------------------------------------------------Stopwatch funcs
# def makeWidgets(self):
# """ Print the time. """
# l = Label(self, textvariable=self.timestr)
# self._setTime(self._elapsedtime)
# l.pack(fill=X, expand=NO, pady=2, padx=2)
def _print(self):
print self._elapsedtime
def _update(self):
""" Update the label with elapsed time. """
self._elapsedtime = time.time() - self._start
self._setTime(self._elapsedtime)
self._timer = self.after(50, self._update)
def _setTime(self, elap):
""" Set the time string to Minutes:Seconds:Hundreths """
minutes = int(elap / 60)
seconds = int(elap - minutes * 60.0)
hseconds = int((elap - minutes * 60.0 - seconds) * 100)
self.timestr.set('%02d:%02d:%02d' % (minutes, seconds, hseconds))
def Start(self):
""" Start the stopwatch, ignore if running. """
print self._elapsedtime
if not self._running:
self._start = time.time() - self._elapsedtime
self._update()
self._running = 1
def insert_to_db(self):
self.sql = "INSERT INTO Table_Assembly ('Finished_Product', 'Lap_Time') VALUES (%s, %s)"
try:
self.execute(sql,( str(self.lbttn_clicks), str(self._elapsedtime)))
self.db.commit()
except:
self.db.rollback()
def read_from_db(self):
try:
#c.execute("SELECT * FROM TTAB_CPU WHERE ID = (SELCET MAX(ID) FROM TAB_CPU)")
self.c.execute("SELECT * FROM Table_Assembly ORDER BY ID DESC LIMIT 1")
self.result = self.c.fetchall()
if result is not None:
print ('Finished_Product: ' , result[0][1], '| Lap_Time: ' , result[0][2])
except:
print ("read error")
def LedGreen(self):
self.rr = self.client.read_coils(0,6)
print "Start Button Pressed"
if self.LedGreen_State == False:
self.rr.bits[3] = True
self.rq = self.client.write_coil(3, True)
self.rq = self.client.write_coil(0, True)
GPIO.output(16, GPIO.LOW)
self.LedGreen_State = True
def LedGreenOff(self):
self.rr = self.client.read_coils(0,6)
print "Green light is off"
if self.LedGreen_State == True:
self.rr.bits[3] = False
self.rq = self.client.write_coil(3, False)
self.rq = self.client.write_coil(0, False)
GPIO.output(16, GPIO.HIGH)
self.LedGreen_State = False
def LedYellow(self):
self.rr = self.client.read_coils(0,6)
print "Request Material"
if self.LedYellow_State == False:
self.rr.bits[4] = True
self.rq = self.client.write_coil(4, True)
self.rq = self.client.write_coil(1, True)
GPIO.output(20, GPIO.LOW)
self.LedYellow_State = True
def LedYellowOff(self):
self.rr = self.client.read_coils(0,6)
print "Material replenished"
if self.LedYellow_State == True:
self.rr.bits[4] = False
self.rq = self.client.write_coil(4, False)
self.rq = self.client.write_coil(1, False)
GPIO.output(20, GPIO.HIGH)
self.LedYellow_State = False
def LedRed(self):
self.rr = self.client.read_coils(0,6)
print "Assembly process jammed"
if self.LedRed_State == False:
self.rr.bits[5] = True
self.rq = self.client.write_coil(5, True)
self.rq = self.client.write_coil(2, True)
GPIO.output(21, GPIO.LOW)
self.LedRed_State = True
def LedRedOff(self):
self.rr = self.client.read_coils(0,6)
print "Red light is off"
if self.LedRed_State == True:
self.rr.bits[5] = False
self.rq = self.client.write_coil(5, False)
self.rq = self.client.write_coil(2, False)
GPIO.output(21, GPIO.HIGH)
self.LedRed_State = False
def Finish(self):
self.rr = self.client.read_coils(0,6)
print "Assembly is finished"
if self.LedGreen_State == True:
self.rr.bits[3] = False
self.rq = self.client.write_coil(3, False)
self.rq = self.client.write_coil(0, False)
GPIO.output(16, GPIO.HIGH)
self.LedGreen_State = False
if self.LedYellow_State == True:
self.rr.bits[4] = False
self.rq = self.client.write_coil(4, False)
self.rq = self.client.write_coil(1, False)
GPIO.output(20, GPIO.HIGH)
self.LedYellow_State = False
if self.LedRed_State == True:
self.rr.bits[5] = False
self.rq = self.client.write_coil(5, False)
self.rq = self.client.write_coil(2, False)
GPIO.output(21, GPIO.HIGH)
self.LedRed_State = False
def Stop(self):
""" Stop the stopwatch, ignore if stopped. """
if self._running:
self.after_cancel(self._timer)
self._elapsedtime = time.time() - self._start
self._setTime(self._elapsedtime)
self._running = 0
GPIO.cleanup()
def Reset(self):
""" Reset the stopwatch. """
self._start = time.time()
self._elapsedtime = 0.0
self._setTime(self._elapsedtime)
def main():
while 1:
insert_to_db()
read_from_db()
if __name__ == '__main__':
try:
db = MySQLdb.connect("localhost","root","raspberry","DB_ASSY")
self.c= self.db.cursor()
except:
print ("No connection to server...")
win = Tk()
win.title("Screen")
win.geometry('800x400')
app = Screen(win)
win.mainloop()
为每条记录生成自动生成的推送键的方式保存和检索数据？
这是我想要存储在特定用户节点中的代码：
firebase realtime database答案 0 :(得分：2)
从我在代码中看到的，数据结构是：
users: {
"$year": {
"$month": {
bill_eml: "...",
bill_name: "...",
bill_due_date: "...",
bill_period: "...",
status: "...",
total: ...,
bill_id: "..."
}
}
}
}
在您当前的数据结构中，您可以轻松加载特定年份或该年内特定月份的所有帐单。如果不加载所有账单并在应用程序代码中过滤，就无法查询此结构中特定用户的所有账单。
在NoSQL数据库中，您必须修改数据模型以允许您为应用程序使用的用例。例如：如果您想允许列出特定用户的账单，您可以修改现有数据结构以存储每个用户的账单：
users: {
"$uid": {
"$year": {
"$month": {
bill_eml: "...",
bill_name: "...",
bill_due_date: "...",
bill_period: "...",
status: "...",
total: ...,
bill_id: "..."
}
}
}
}
}
现在，您可以通过加载/users/$uid来获取特定用户的帐单。
但是，当然，通过这种修改后的结构，现在再也无法为特定月份的所有用户获取账单。如果您想要两个用例（特定用户的所有账单，特定月份所有用户的所有账单），您可能需要复制一些数据。例如：
users: {
"$uid": {
"$year": {
"$month": {
}
}
}
}
months: {
"$year": {
"$month": {
}
}
如果您是这种数据结构的新手，我强烈建议您阅读NoSQL data modeling。如果您来自更传统的关系数据库背景，我建议您观看Firebase for SQL developers。