#SQLtips

SQL beginners: WHERE vs HAVING WHERE filters rows before grouping. HAVING filters groups after aggregation. Example: SELECT department, COUNT() FROM employees WHERE salary > 100000 GROUP BY department HAVING COUNT() > 5; Master this #SQLTips #DataAnalysis

How to practice SQL when you don’t have a job yet 1/ Use free online tools (SQLZoo, Mode Analytics dataset, or Excel Power Query) 2/ Download free public data (sales, or government open data) 3/ Build 3 simple projects and put them on GitHub or LinkedIn #SQLTips #DataAnalysis

5 SQL mistakes Beginners make (and how to fix them) 1 Writing SELECT * every time. 2 Forgetting WHERE. 3 Mixing JOIN types randomly. 4 Not using aliases. 5 Copy-pasting code without understanding. Reply SQL #SQLTips #DataAnalysis #LearnSQL

SQL tip that saved me hours: Use CTEs (WITH) instead of nested subqueries. They are easier to read and debug. Example: WITH sales AS ( SELECT customer_id, SUM(amount) AS total FROM orders GROUP BY customer_id ) SELECT * FROM sales WHERE total > 1000; #SQLTips #DataAnalysis

SQL tip: Always use aliases. Bad: SELECT orders.amount Good: SELECT o.amount FROM customers c JOIN orders o Your future self (and anyone reviewing your code) will thank you. #SQLTips #DataAnalysis #CleanCode

Two tables, one UNION. How many rows come back? 🤔 #SQLQuiz #LearnSQL #SQLTips #DataAnalytics #SQLChallenge

SQL tip beginners miss: COUNT(*) counts all rows. COUNT(column) ignores NULLs. Use COUNT(*) when you want total records. Use COUNT(column) when you want non-empty values only. Small difference, big accuracy impact. Save this. #SQLTips #DataAnalysis

Scary SQL moment 😬 UPDATE students SET city = 'Delhi'; No WHERE clause = every row gets updated! Safe habit: Run a SELECT with the same WHERE condition first. Verify the rows, then UPDATE. One missing WHERE can change the whole table! #SQL #SQLTips

Which skill are you focusing on this weekend? ExcelTips SQLTips PowerBI Reply after voting if you want a free practice file for that skill. #DataAnalysis #ExcelTips #SQLTips #PowerBI

Power BI + SQL combo tip: Don’t clean everything in Power Query if you can clean it in SQL first. Push the heavy lifting to the database. Your reports will load faster. Small habit. Big difference. #PowerBI #SQLTips #DataAnalysis

Робота з SQL стає простішою, коли основні функції доведено до автоматизму. Від агрегацій і віконних функцій до роботи з рядками, датами, умовною логікою та фільтрацією — це саме ті інструменти, які аналітики використовують постійно. #SQL #SQLTips #DataAnalytics #DataAnalyst