task: #1158

Author: Ivanbyone

README.md

@@ -1,8 +1,8 @@
 # Leetcode (PostgreSQL)
 
+![Postgres](https://img.shields.io/badge/postgres-%23316192.svg?style=for-the-badge&logo=postgresql&logoColor=white)
 [![MIT licensed](https://img.shields.io/badge/License-MIT-yellow.svg)](./LICENSE)
 [![CI](https://github.com/ivanbyone/leetcode-sql/actions/workflows/ci.yml/badge.svg)](https://github.com/Ivanbyone/leetcode-sql//actions)
-![Postgres](https://img.shields.io/badge/postgres-%23316192.svg?style=for-the-badge&logo=postgresql&logoColor=white)
 
 ## Description
 
@@ -46,6 +46,7 @@ Have a good contributing!
 2. [Medium](./leetcode/medium/)
     - [176. Second Highest Salary](./leetcode/medium/176.%20Second%20Highest%20Salary.sql)
     - [184. Department Highest Salary](./leetcode/medium/184.%20Department%20Highest%20Salary.sql)
+    - [1158. Market Analysis 1](./leetcode/medium/1158.%20Market%20Analysis%201.sql)
 
 ## License
 

leetcode/medium/1158. Market Analysis 1.sql

@@ -0,0 +1,60 @@
+/*
+Question 1158. Market Analysis 1
+Link: https://leetcode.com/problems/market-analysis-i/description/
+
+Table: Users
+
++----------------+---------+
+| Column Name    | Type    |
++----------------+---------+
+| user_id        | int     |
+| join_date      | date    |
+| favorite_brand | varchar |
++----------------+---------+
+user_id is the primary key (column with unique values) of this table.
+This table has the info of the users of an online shopping website where users can sell and buy items.
+ 
+
+Table: Orders
+
++---------------+---------+
+| Column Name   | Type    |
++---------------+---------+
+| order_id      | int     |
+| order_date    | date    |
+| item_id       | int     |
+| buyer_id      | int     |
+| seller_id     | int     |
++---------------+---------+
+order_id is the primary key (column with unique values) of this table.
+item_id is a foreign key (reference column) to the Items table.
+buyer_id and seller_id are foreign keys to the Users table.
+ 
+
+Table: Items
+
++---------------+---------+
+| Column Name   | Type    |
++---------------+---------+
+| item_id       | int     |
+| item_brand    | varchar |
++---------------+---------+
+item_id is the primary key (column with unique values) of this table.
+ 
+
+Write a solution to find for each user, the join date and the number of orders they made as a buyer in 2019.
+
+Return the result table in any order.
+*/
+
+SELECT 
+    u.user_id AS buyer_id,
+    u.join_date,
+    COUNT(o.order_id) AS orders_in_2019
+FROM Users AS u
+LEFT JOIN 
+    Orders AS o
+    ON 
+        u.user_id = o.buyer_id
+        AND o.order_date BETWEEN '2019-01-01' AND '2019-12-31'
+GROUP BY u.user_id, u.join_date