task: #2356

Author: Ivanbyone

README.md

@@ -63,6 +63,7 @@ Have a good contributing!
     - [1729. Find Followers Count](./leetcode/easy/1729.%20Find%20Followers%20Count.sql)
     - [1741. Find Total Time Spent by Each Employee](./leetcode/easy/1741.%20Find%20Total%20Time%20Spent%20by%20Each%20Employee.sql)
     - [1965. Employees With Missing Information](./leetcode/easy/1965.%20Employees%20With%20Missing%20Information.sql)
+    - [2356. Number of Unique Subjects Taught by Each Teacher](./leetcode/easy/2356.%20Number%20of%20Unique%20Subjects%20Taught%20by%20Each%20Teacher.sql)
 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)

leetcode/easy/2356. Number of Unique Subjects Taught by Each Teacher.sql

@@ -0,0 +1,27 @@
+/*
+Question 2356. Number of Unique Subjects Taught by Each Teacher
+Link: https://leetcode.com/problems/number-of-unique-subjects-taught-by-each-teacher/description/?envType=study-plan-v2&envId=top-sql-50
+
+Table: Teacher
+
++-------------+------+
+| Column Name | Type |
++-------------+------+
+| teacher_id  | int  |
+| subject_id  | int  |
+| dept_id     | int  |
++-------------+------+
+(subject_id, dept_id) is the primary key (combinations of columns with unique values) of this table.
+Each row in this table indicates that the teacher with teacher_id teaches the subject subject_id in the department dept_id.
+ 
+
+Write a solution to calculate the number of unique subjects each teacher teaches in the university.
+
+Return the result table in any order.
+*/
+
+SELECT
+    teacher_id,
+    COUNT(DISTINCT subject_id) AS cnt
+FROM Teacher
+GROUP BY teacher_id