5.7K
DADay 24 SQL 🔥| This SQL NULL mistake can fail your interview ❌
IFNULL vs COALESCE explained simply.
SAVE this and SHARE with your Data Analyst batch 📊
📺 Follow on YouTube: Link in Bio
👉 www.youtube.com/@DataXOdyssey
❓ Problem
Your SQL results may look correct — but still be wrong ❌
When data contains NULL, calculations and reports can break…
✅ IFNULL() – Replace NULL with a default value
SELECT IFNULL(Salary, 0) AS Salary
FROM employees;
👉 If Salary is NULL → replace it with 0
👉 Works with only ONE fallback value
✅ COALESCE() – Pick first non-NULL value
SELECT COALESCE(Salary, Bonus, 0) AS Final_Pay
FROM employees;
👉 Checks values from left to right
👉 Returns the first value that is NOT NULL
👉 Can handle multiple columns
🎯 Interview Tip:
Use COALESCE when multiple fallback values are possible
Use IFNULL when logic is simple and limited
🧠 Understand the difference (IMPORTANT 👇)
• IFNULL
✔ Simple
✔ Only 2 arguments
✔ Good when you need one replacement
• COALESCE
✔ More powerful
✔ Multiple arguments
✔ Works across different SQL databases
✔ Preferred in real-world analytics
📌 This is why COALESCE is more flexible than IFNULL
📌 Part of Daily SQL Series – Day 24
🔁 Missed earlier days? Check out previous videos to learn SQL from scratch
🔁 Save this
📌 Follow for daily SQL learning
🔁 DAY SERIES FLOW
👉 Check Out Day 23: NULL vs IS NULL vs IS NOT NULL
#LearnSQL
#SQLTutorial
#SQLTips
#SQLBeginners
#DataAnalytics
#DataAnalystJourney
#SQLInterview
#TechCareers
#MySQL
#PostgreSQL
#Day24SQL
#DataXOdyssey
@dataxodyssey
