Question

我是iOS新手。我正在创建一个应用程序，用户将根据他们指定的日期将客户端名称存储在数据库中。

id Day         Client1    Client2    Client3    Client4    Client5    Client6
0  Monday      Nitin      Vijay      Akshay     Ajit       Sahil      Ravi
1  Tuesday     Ravi       Akshay     Nitin      Sahil      Vijay      Ajit    
2  Wednesday   Vijay      Nitin      Vijay      Akshay     Ravi       Ajit
3  Thursday    Akshay     Ajit       Nitin      Ravi       Sahil      Vijay
4  Friday      Nitin      Nitin      Akshay     Sahil      Ravi       Vijay

有些客户每天都会重复，如何计算每个客户遇到我的次数，并将其每天保存到int。

例如

Monday
Nitin = 1
Vijay = 1
Akshay = 1
Ajit = 1
Sahil = 1
Ravi = 1

这应该每天上午12:00更新，如果我要求数据库在周二显示计数，它应该附带（周一计数+周二计数）

Tuesday
Nitin = 2
Vijay = 2
Akshay = 2
Ajit = 2
Sahil = 2
Ravi = 2

我应该如何实现它？

Answer 1

假设您已使用以下表格对数据库进行了规范化：

Days:  id  Day
       0   Monday
       1   Tuesday
       2   Wednesday
       ...

Appointments:  DayID  Client
               0      Nitin
               0      Vijay
               0      Akshay
               0      Ajit
               0      Sahil
               0      Ravi
               1      Ravi
               1      Akshay
               1      Nitin
               ...

然后您可以简单地计算每个客户的记录：

SELECT Client, COUNT(*)
FROM Appointments
WHERE DayID BETWEEN 0 AND 1  -- Monday and Tuesday
GROUP BY Client

计算数据库中的条目

1 个答案: