Spelling SQL column name wrong, then it works

You can learn all of this in weeks. Knowing SQL ≠ Being job ready Can you write queries without guidance? Can you debug when it breaks? That’s the real test.

“Here is some basic SQL notes… saved for future me (and anyone else who needs it).” Because let’s be honest — we all learn SQL… and then forget the syntax the moment we actually need it 😅 So instead of pretending I’ll remember everything, I decided to document the basics: - Core queries - Filtering - Aggregations - Joins & more Nothing fancy. Just the stuff that actually gets used. Sometimes the smartest thing in tech isn’t knowing everything… it’s knowing where you saved it 😉 #SQL #DataAnalytics #DataScience #LearningInPublic #TechNotes

🗓️ SQL Challenge Day #27: Biggest Single Number 🔹 Find the largest number that appears exactly once! 🔢 🔹 Problem:   Return the biggest "single" number (appears only once):   ✅ If no such number exists, return NULL  🔹 Solution:  SELECT     MAX(num) AS num FROM (     SELECT         num,         COUNT(1) AS cnt     FROM         MyNumbers     GROUP BY         num     HAVING         cnt = 1 ) t;   ✅ Result: Accepted  💡 Key Takeaway:   **MAX() handles NULL gracefully!** The outer query returns NULL automatically if the inner subquery finds no single numbers – no extra logic needed. This is cleaner than using CASE or IFNULL here.  👇 Your turn:   What’s your go-to pattern for handling "return NULL if empty result" scenarios in SQL?  #SQL #LeetCode #DataEngineering #ProblemSolving #Coding #LearningInPublic #Database #DataAnalytics

SQL is the backbone of data work, but even the pros forget the specific order of a WINDOW FUNCTION or the difference between UNION and UNION ALL sometimes. I put together this comprehensive SQL Cheat Sheet to keep all the essentials in one place—from basic DML to advanced CTEs and Triggers. ✅ What’s inside: Joins & Set Operations Window Functions & Aggregations Date/Time formatting Transaction control Save this post 📌 so you can find it during your next project, and Tag a friend who’s currently learning SQL! #SQL #DataScience #DataAnalytics #Coding #Database #ProgrammingTips

🚀 EXISTS in SQL 💡 What is EXISTS? ✔️ Check if a subquery returns any rows ✔️ Returns TRUE if at least 1 row exists ✔️ Returns FALSE if no rows 🔍 How it works: ➡️ Outer query runs ➡️ Inner query checks for matching rows ➡️ If a match is found, the row is included ➡️ If no match, the row is excluded 🗝️ Key Concept 👉 EXISTS does not care about values 👉 It only checks if rows exist 🧠 Even if the subquery returns NULL ➡️ EXISTS can still be TRUE #SQL #DataAnalytics #LearningSQL #TechTips #InterviewPrep #DataEngineering

Day 18 of my SQL learning journey has been insightful as I explored the CASE Statement. I applied IF-THEN logic in SQL, categorized data using conditions, and created dynamic columns. A key takeaway from today is the importance of transforming data using logic, not just queries. SQL continues to grow in power every day. #SQL #LearningJourney #Day18 #DataAnalytics #TechSkills

Window Functions in SQL always felt confusing to me — especially OVER(), PARTITION BY and ORDER BY. So I tried breaking it down in the simplest way possible. A detailed explanation on all window functions will be in the next post. Till then, happy learning 🚀 #SQL #DataEngineering #WindowFunctions #openfornewopportunity #datalearning

🗓️ SQL Challenge Day #32: Consecutive Numbers 🔹 Find numbers appearing 3+ times in a row! 🔢 🔹 Problem:   Identify values with ≥3 consecutive occurrences:   ✅ Consecutive = sequential `id` values   ✅ Return distinct numbers only  🔹 Solution (Window Function Approach):  SELECT distinct num AS ConsecutiveNums FROM (     SELECT         num,         id,         LEAD(id) OVER (PARTITION BY num ORDER BY id) AS l1,         LEAD(id, 2) OVER (PARTITION BY num ORDER BY id) AS l2     FROM Logs ) t WHERE l1 - id = 1   AND l2 - l1 = 1; ✅ Result: Accepted  💡 Key Takeaway:   **LEAD() checks sequence gaps!** By comparing current `id` with next two `id`s:   - `l1 - id = 1` → next record is immediate successor   - `l2 - l1 = 1` → third record is also consecutive   ⚠️ Why partition by `num`? Ensures we only compare same numbers!  👇 Your turn:   Have you used LAG/LEAD for detecting sequences in logs or time-series data? What patterns did you find?  #SQL #LeetCode #DataEngineering #ProblemSolving #Coding #LearningInPublic #Database #DataAnalytics

Day 15 of My DSA Journey - SQL Shifted focus to SQL today and worked on multiple problems from the SQL study plan on LeetCode What I learned: • How to retrieve and filter data using SELECT • Using JOINs to combine multiple tables • Applying GROUP BY and aggregate functions • Writing clean and structured queries Progress so far: • 23 out of 50 SQL problems completed Insight: SQL problems are less about syntax and more about understanding the data and relationships between tables. Once the logic is clear, writing the query becomes straightforward. #DSA #SQL #ProblemSolving #LearningJourney #Database