5.7K
DADay 24 SQL π₯| This SQL NULL mistake can fail your interview β
IFNULL vs COALESCE explained simply.
SAVE this and SHARE with your Data Analyst batch π
πΊ Follow on YouTube: Link in Bio
π www.youtube.com/@DataXOdyssey
β Problem
Your SQL results may look correct β but still be wrong β
When data contains NULL, calculations and reports can breakβ¦
β
IFNULL() β Replace NULL with a default value
SELECT IFNULL(Salary, 0) AS Salary
FROM employees;
π If Salary is NULL β replace it with 0
π Works with only ONE fallback value
β
COALESCE() β Pick first non-NULL value
SELECT COALESCE(Salary, Bonus, 0) AS Final_Pay
FROM employees;
π Checks values from left to right
π Returns the first value that is NOT NULL
π Can handle multiple columns
π― Interview Tip:
Use COALESCE when multiple fallback values are possible
Use IFNULL when logic is simple and limited
π§ Understand the difference (IMPORTANT π)
β’ IFNULL
β Simple
β Only 2 arguments
β Good when you need one replacement
β’ COALESCE
β More powerful
β Multiple arguments
β Works across different SQL databases
β Preferred in real-world analytics
π This is why COALESCE is more flexible than IFNULL
π Part of Daily SQL Series β Day 24
π Missed earlier days? Check out previous videos to learn SQL from scratch
π Save this
π Follow for daily SQL learning
π DAY SERIES FLOW
π 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
