Leetcode 14 || 🔥 Leetcode #2356 SQL Solution | SQL Interview Question Explained

👋 Hey everyone! Welcome back to the channel.
Today, we’re solving Leetcode Problem 2356 – Number of Unique Subjects Taught by Each Teacher using SQL.
Let’s say we have a Teacher table with columns teacher_id and subject. Some teachers teach the same subject multiple times — we only want to count unique subjects per teacher.
✅ Here’s the goal: For each teacher, return the number of distinct subjects they teach.
🔍 To do this, we’ll use:
COUNT(DISTINCT subject)
GROUP BY teacher_id

Видео Leetcode 14 || 🔥 Leetcode #2356 SQL Solution | SQL Interview Question Explained канала Siri bhargavi