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README.md

@@ -152,6 +152,7 @@ To make the daily tasks of creating a new file and updating the index easier, th
 | 121   | [Find Followers Count](https://leetcode.com/problems/find-followers-count/description/)                                                                       | [Solution](solutions/121_find_followers_count.md)                                     | LeetCode    | Easy         |   |
 | 122   | [Biggest Single Number](https://leetcode.com/problems/biggest-single-number/description/)                                                                     | [Solution](solutions/122_biggest_single_number.md)                                    | LeetCode    | Easy         |   |
 | 123   | [Customers Who Bought All Products](https://leetcode.com/problems/customers-who-bought-all-products/description/)                                             | [Solution](solutions/123_customers_who_bought_all_products.md)                        | LeetCode    | Medium       |   |
+| 124   | [The Number of Employees Which Report to Each Employee](https://leetcode.com/problems/the-number-of-employees-which-report-to-each-employee/description/)     | [Solution](solutions/124_the_number_of_employees_which_report_to_each_employee.md)    | LeetCode    | Easy         |   |
 
 ## Author(s)
 

solutions/124_the_number_of_employees_which_report_to_each_employee.md

@@ -0,0 +1,64 @@
+# SQL Everyday \#124
+
+## The Number of Employees Which Report to Each Employee
+
+Site: LeetCode\
+Difficulty per Site: Easy
+
+## Problem
+
+Write a solution to report the ids and the names of all *managers*, the number of employees who report *directly* to them, and the average age of the reports rounded to the nearest integer.
+
+Return the result table ordered by `employee_id`. [[Full Description](https://leetcode.com/problems/the-number-of-employees-which-report-to-each-employee/description/)]
+
+## Submitted Solution
+
+```sql
+-- Submitted Solution
+SELECT 
+    e1.employee_id
+    ,e1.name
+    ,COUNT(e2.employee_id) AS reports_count
+    ,ROUND(AVG(e2.age)) AS average_age
+FROM Employees e1
+JOIN Employees e2 ON e1.employee_id = e2.reports_to
+WHERE e2.reports_to IS NOT NULL
+GROUP BY e1.employee_id
+ORDER BY e1.employee_id
+;
+```
+
+## Site Solution
+
+```sql
+-- LeetCode Solution 
+SELECT 
+  reports_to AS employee_id, 
+  (
+    SELECT 
+      name 
+    FROM 
+      employees e1 
+    WHERE 
+      e.reports_to = e1.employee_id 
+  ) AS name, 
+  COUNT(reports_to) AS reports_count, 
+  ROUND(
+    AVG(age)
+  ) AS average_age 
+FROM 
+  employees e 
+GROUP BY 
+  reports_to 
+HAVING 
+  reports_count > 0 
+ORDER BY 
+  employee_id
+```
+
+## Notes
+
+TODO
+
+Go to [Table of Contents](/README.md#contents)\
+Go to [Overview](/README.md)