refactor 262

Author: fishercoder1534

database/_262.sql

@@ -1,48 +1,3 @@
---262. Trips and Users
---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 clients 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        |
---+------------+-------------------+
---Credits:
---Special thanks to @cak1erlizhou for contributing this question, writing the problem description and adding part of the test cases.
-
 select t.Request_at as Day,
 round(sum(case when t.Status like 'cancelled_%' then 1 else 0 end)/count(*), 2) as 'Cancellation Rate'
 from Trips t