MEDIUM

Author: evanmathew

1193. Monthly Transactions I.sql

@@ -1,3 +1,56 @@
+-- Problem:
+
+/*
+Table: Transactions
+
++---------------+---------+
+| Column Name   | Type    |
++---------------+---------+
+| id            | int     |
+| country       | varchar |
+| state         | enum    |
+| amount        | int     |
+| trans_date    | date    |
++---------------+---------+
+id is the primary key of this table.
+The table has information about incoming transactions.
+The state column is an enum of type ["approved", "declined"].
+ 
+
+Write an SQL query to find for each month and country, the number of transactions and their total amount, the number of approved transactions and their total amount.
+
+Return the result table in any order.
+
+The query result format is in the following example.
+
+ 
+
+Example 1:
+
+Input: 
+Transactions table:
++------+---------+----------+--------+------------+
+| id   | country | state    | amount | trans_date |
++------+---------+----------+--------+------------+
+| 121  | US      | approved | 1000   | 2018-12-18 |
+| 122  | US      | declined | 2000   | 2018-12-19 |
+| 123  | US      | approved | 2000   | 2019-01-01 |
+| 124  | DE      | approved | 2000   | 2019-01-07 |
++------+---------+----------+--------+------------+
+Output: 
++----------+---------+-------------+----------------+--------------------+-----------------------+
+| month    | country | trans_count | approved_count | trans_total_amount | approved_total_amount |
++----------+---------+-------------+----------------+--------------------+-----------------------+
+| 2018-12  | US      | 2           | 1              | 3000               | 1000                  |
+| 2019-01  | US      | 1           | 1              | 2000               | 2000                  |
+| 2019-01  | DE      | 1           | 1              | 2000               | 2000                  |
++----------+---------+-------------+----------------+--------------------+-----------------------+`
+*/
+
+-------------------------------------------------------------------------------
+
+-- Solution:
+
 SELECT 
     DATE_FORMAT(trans_date, "%Y-%m") AS month,
     country,