# 1127. User Purchase Platform

<https://leetcode.com/problems/user-purchase-platform>

## Description

Table: `Spending`

```
+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| user\_id     | int     |
| spend\_date  | date    |
| platform    | enum    | 
| amount      | int     |
+-------------+---------+
The table logs the spendings history of users that make purchases from an online shopping website which has a desktop and a mobile application.
(user\_id, spend\_date, platform) is the primary key of this table.
The platform column is an ENUM type of ('desktop', 'mobile').
```

Write an SQL query to find the total number of users and the total amount spent using mobile **only**, desktop **only** and **both** mobile and desktop together for each date.

The query result format is in the following example:

```
Spending table:
+---------+------------+----------+--------+
| user\_id | spend\_date | platform | amount |
+---------+------------+----------+--------+
| 1       | 2019-07-01 | mobile   | 100    |
| 1       | 2019-07-01 | desktop  | 100    |
| 2       | 2019-07-01 | mobile   | 100    |
| 2       | 2019-07-02 | mobile   | 100    |
| 3       | 2019-07-01 | desktop  | 100    |
| 3       | 2019-07-02 | desktop  | 100    |
+---------+------------+----------+--------+
Result table:
+------------+----------+--------------+-------------+
| spend\_date | platform | total\_amount | total\_users |
+------------+----------+--------------+-------------+
| 2019-07-01 | desktop  | 100          | 1           |
| 2019-07-01 | mobile   | 100          | 1           |
| 2019-07-01 | both     | 200          | 1           |
| 2019-07-02 | desktop  | 100          | 1           |
| 2019-07-02 | mobile   | 100          | 1           |
| 2019-07-02 | both     | 0            | 0           |
+------------+----------+--------------+-------------+ 
On 2019-07-01, user 1 purchased using **both** desktop and mobile, user 2 purchased using mobile **only** and user 3 purchased using desktop **only**.
On 2019-07-02, user 2 purchased using mobile **only**, user 3 purchased using desktop **only** and no one purchased using **both** platforms.
```

## ac

```java
```