我希望数据库只存储事件。这些事件将来自他们接触RFID的时候。卡将有一个ID/员工编号。
处理数据库信息将允许计算谁在轮班以及轮班工作的长度等。

如果某个员工的录入数为奇数，则您可以假定他们正在轮班。录入数为偶数则表示他们已完成轮班。
我没有你的硬件或数据库，所以我创建了随机RFID读取事件，并使用sqlite3。

import datetime
import random
import sqlite3
import time

class SimpleMFRC522:
    @staticmethod
    def read():
        while random.randint(0, 30) != 10:  # Create some delay/blocking
            time.sleep(1)
        employee_id = random.randint(0, 5)
        return employee_id, f'employee_{employee_id}'

class MyDatabase:
    def __init__(self):
        self.db = sqlite3.connect('/tmp/my-test.db')
        with self.db:
            self.db.execute("""
            CREATE TABLE IF NOT EXISTS workers (
                        id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
                        empl_no INTEGER,
                        name TEXT,
                        tap_event timestamp);
            """)
            self.db.commit()

    def insert_event(self, empl_no, name, timestamp):
        sqlite_insert_with_param = """INSERT INTO 'workers'
                                  ('empl_no', 'name', 'tap_event') 
                                  VALUES (?, ?, ?);"""
        self.db.cursor()
        self.db.execute(sqlite_insert_with_param, (empl_no, name, timestamp))
        self.db.commit()

    def worker_in(self, empl_no):
        sql_cmd = f"SELECT COUNT(*) FROM workers WHERE empl_no = {empl_no};"
        cursor = self.db.execute(sql_cmd)
        event_count, = cursor.fetchone()
        return event_count % 2 == 1 and event_count > 0

    def last_shift(self, empl_no):
        sql_cmd = f"""SELECT tap_event FROM 
                        (SELECT * FROM workers WHERE empl_no = {empl_no} ORDER BY tap_event DESC LIMiT 2) 
                        ORDER BY tap_event ASC ;"""
        cursor = self.db.execute(sql_cmd)
        tap_in, tap_out = cursor.fetchall()
        start = datetime.datetime.fromtimestamp(tap_in[0])
        end = datetime.datetime.fromtimestamp(tap_out[0])
        return end - start

def main():
    db = MyDatabase()
    reader = SimpleMFRC522()
    while True:
        empl_no, name = reader.read()
        print(f"adding tap event for {name}")
        db.insert_event(empl_no, name, datetime.datetime.timestamp(datetime.datetime.now()))
        if db.worker_in(empl_no):
            print(f"\t{name} has started their shift")
        else:
            time_worked = db.last_shift(empl_no)
            print(f"\t{name} has left the building after {time_worked}")

if __name__ == '__main__':
    main()

这给了我一份成绩单如下

adding tap event for employee_5
    employee_5 has started their shift
adding tap event for employee_0
    employee_0 has left the building after 0:02:10.154697
adding tap event for employee_3
    employee_3 has left the building after 0:07:02.465903
adding tap event for employee_3
    employee_3 has started their shift
adding tap event for employee_2
    employee_2 has left the building after 0:06:27.403874
adding tap event for employee_2
    employee_2 has started their shift