[SQL]LeetCode262.行程和用戶 | Trips and Users

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SQL架構

 1 Create table If Not Exists Trips (Id int, Client_Id int, Driver_Id int, City_Id int, Status ENUM('completed', 'cancelled_by_driver', 'cancelled_by_client'), Request_at varchar(50))
 2 Create table If Not Exists Users (Users_Id int, Banned varchar(50), Role ENUM('client', 'driver', 'partner'))
 3 Truncate table Trips
 4 insert into Trips (Id, Client_Id, Driver_Id, City_Id, Status, Request_at) values ('1', '1', '10', '1', 'completed', '2013-10-01')
 5 insert into Trips (Id, Client_Id, Driver_Id, City_Id, Status, Request_at) values ('2', '2', '11', '1', 'cancelled_by_driver', '2013-10-01')
 6 insert into Trips (Id, Client_Id, Driver_Id, City_Id, Status, Request_at) values ('3', '3', '12', '6', 'completed', '2013-10-01')
 7 insert into Trips (Id, Client_Id, Driver_Id, City_Id, Status, Request_at) values ('4', '4', '13', '6', 'cancelled_by_client', '2013-10-01')
 8 insert into Trips (Id, Client_Id, Driver_Id, City_Id, Status, Request_at) values ('5', '1', '10', '1', 'completed', '2013-10-02')
 9 insert into Trips (Id, Client_Id, Driver_Id, City_Id, Status, Request_at) values ('6', '2', '11', '6', 'completed', '2013-10-02')
10 insert into Trips (Id, Client_Id, Driver_Id, City_Id, Status, Request_at) values ('7', '3', '12', '6', 'completed', '2013-10-02')
11 insert into Trips (Id, Client_Id, Driver_Id, City_Id, Status, Request_at) values ('8', '2', '12', '12', 'completed', '2013-10-03')
12 insert into Trips (Id, Client_Id, Driver_Id, City_Id, Status, Request_at) values ('9', '3', '10', '12', 'completed', '2013-10-03')
13 insert into Trips (Id, Client_Id, Driver_Id, City_Id, Status, Request_at) values ('10', '4', '13', '12', 'cancelled_by_driver', '2013-10-03')
14 Truncate table Users
15 insert into Users (Users_Id, Banned, Role) values ('1', 'No', 'client')
16 insert into Users (Users_Id, Banned, Role) values ('2', 'Yes', 'client')
17 insert into Users (Users_Id, Banned, Role) values ('3', 'No', 'client')
18 insert into Users (Users_Id, Banned, Role) values ('4', 'No', 'client')
19 insert into Users (Users_Id, Banned, Role) values ('10', 'No', 'driver')
20 insert into Users (Users_Id, Banned, Role) values ('11', 'No', 'driver')
21 insert into Users (Users_Id, Banned, Role) values ('12', 'No', 'driver')
22 insert into Users (Users_Id, Banned, Role) values ('13', 'No', 'driver')

---

The Trips table holds all taxi trips. Each trip has a unique Id, while Client_Id and Driver_Id are both foreign keys to the Users_Id at the Users table. Status is an ENUM type of (‘completed’, ‘cancelled_by_driver’, ‘cancelled_by_client’).

+----+-----------+-----------+---------+--------------------+----------+
| Id | Client_Id | Driver_Id | City_Id |        Status      |Request_at|
+----+-----------+-----------+---------+--------------------+----------+
| 1  |     1     |    10     |    1    |     completed      |2013-10-01|
| 2  |     2     |    11     |    1    | cancelled_by_driver|2013-10-01|
| 3  |     3     |    12     |    6    |     completed      |2013-10-01|
| 4  |     4     |    13     |    6    | cancelled_by_client|2013-10-01|
| 5  |     1     |    10     |    1    |     completed      |2013-10-02|
| 6  |     2     |    11     |    6    |     completed      |2013-10-02|
| 7  |     3     |    12     |    6    |     completed      |2013-10-02|
| 8  |     2     |    12     |    12   |     completed      |2013-10-03|
| 9  |     3     |    10     |    12   |     completed      |2013-10-03| 
| 10 |     4     |    13     |    12   | cancelled_by_driver|2013-10-03|
+----+-----------+-----------+---------+--------------------+----------+

The Users table holds all users. Each user has an unique Users_Id, and Role is an ENUM type of (‘client’, ‘driver’, ‘partner’).

+----------+--------+--------+
| Users_Id | Banned |  Role  |
+----------+--------+--------+
|    1     |   No   | client |
|    2     |   Yes  | client |
|    3     |   No   | client |
|    4     |   No   | client |
|    10    |   No   | driver |
|    11    |   No   | driver |
|    12    |   No   | driver |
|    13    |   No   | driver |
+----------+--------+--------+

Write a SQL query to find the cancellation rate of requests made by unbanned users between Oct 1, 2013 and Oct 3, 2013. For the above tables, your SQL query should return the following rows with the cancellation rate being rounded to two decimal places.

+------------+-------------------+
|     Day    | Cancellation Rate |
+------------+-------------------+
| 2013-10-01 |       0.33        |
| 2013-10-02 |       0.00        |
| 2013-10-03 |       0.50        |
+------------+-------------------+

---

Trips 表中存全部出租車的行程信息。每段行程有惟一鍵 Id，Client_Id 和 Driver_Id 是 Users 表中 Users_Id 的外鍵。Status 是枚舉類型，枚舉成員爲 (‘completed’, ‘cancelled_by_driver’, ‘cancelled_by_client’)。

+----+-----------+-----------+---------+--------------------+----------+
| Id | Client_Id | Driver_Id | City_Id |        Status      |Request_at|
+----+-----------+-----------+---------+--------------------+----------+
| 1  |     1     |    10     |    1    |     completed      |2013-10-01|
| 2  |     2     |    11     |    1    | cancelled_by_driver|2013-10-01|
| 3  |     3     |    12     |    6    |     completed      |2013-10-01|
| 4  |     4     |    13     |    6    | cancelled_by_client|2013-10-01|
| 5  |     1     |    10     |    1    |     completed      |2013-10-02|
| 6  |     2     |    11     |    6    |     completed      |2013-10-02|
| 7  |     3     |    12     |    6    |     completed      |2013-10-02|
| 8  |     2     |    12     |    12   |     completed      |2013-10-03|
| 9  |     3     |    10     |    12   |     completed      |2013-10-03| 
| 10 |     4     |    13     |    12   | cancelled_by_driver|2013-10-03|
+----+-----------+-----------+---------+--------------------+----------+

Users 表存全部用戶。每一個用戶有惟一鍵 Users_Id。Banned 表示這個用戶是否被禁止，Role 則是一個表示（‘client’, ‘driver’, ‘partner’）的枚舉類型。

+----------+--------+--------+
| Users_Id | Banned |  Role  |
+----------+--------+--------+
|    1     |   No   | client |
|    2     |   Yes  | client |
|    3     |   No   | client |
|    4     |   No   | client |
|    10    |   No   | driver |
|    11    |   No   | driver |
|    12    |   No   | driver |
|    13    |   No   | driver |
+----------+--------+--------+

寫一段 SQL 語句查出 2013年10月1日 至 2013年10月3日 期間非禁止用戶的取消率。基於上表，你的 SQL 語句應返回以下結果，取消率（Cancellation Rate）保留兩位小數。

+------------+-------------------+
|     Day    | Cancellation Rate |
+------------+-------------------+
| 2013-10-01 |       0.33        |
| 2013-10-02 |       0.00        |
| 2013-10-03 |       0.50        |
+------------+-------------------+

---

158ms

1 # Write your MySQL query statement below
2 select request_at Day, round(sum(if(t.Status like 'cancelled%',1,0))/ count(t.Status),2) as 'Cancellation Rate'
3 from trips t
4 join users u
5 on t.client_id = u.users_id
6 and u.banned = 'No'
7 where request_at BETWEEN '2013-10-01' AND '2013-10-03'
8 group by request_at;

---

160ms

 1 select
 2     R1.Request_at as `Day`,
 3         round(sum(case when R1.Status !='completed' -- in ('cancelled_by_driver','cancelled_by_client') 
 4         then 1
 5         else 0
 6     end)/count(1),2)
 7          as `Cancellation Rate`
 8 from
 9     Trips R1 
10     left join Users R2 on R1.Client_Id = R2.Users_Id
11     left join Users R3 on R1.Driver_Id = R3.Users_Id 
12 where
13             R1.Request_at between '2013-10-01' and '2013-10-03'
14     and R2.Banned = 'No'
15     and R3.Banned = 'No'
16 group by R1.Request_at
17 order by R1.Request_at

---

162ms

 1 # Write your MySQL query statement below
 2 select
 3 a.request_at as Day,
 4 round(sum(case when status like 'cancelled_by_%'then 1 else 0 end)/count(id),2) as 'Cancellation Rate'
 5 from
 6 trips a
 7 left join
 8 users b
 9 on a.client_id=b.users_id 
10 where b.role='client' and b.banned='No' and a.request_at between '2013-10-01' and '2013-10-03'
11 group by 1
12 order by 1

---

164ms

1 # Write your MySQL query statement below
2 SELECT T.Request_at as Day, ROUND(SUM(IF(T.Status like "cancelled%", 1, 0))/COUNT(T.Status), 2) as "Cancellation Rate"
3 From Trips as T
4 WHERE (T.Client_Id IN (SELECT Users_Id as aUsers From Users WHERE (Banned like "No") AND (Role like "client"))) 
5         AND (T.Driver_Id IN (SELECT Users_Id as aDrivers From Users WHERE (Banned like "No") AND (Role like "driver")))
6         AND (Request_at BETWEEN "2013-10-01" AND "2013-10-03")
7 GROUP BY Day