✅SQL Checklist for Data Analysts 📀🧠
1. SQL Basics⦁ SELECT, WHERE, ORDER BY
⦁ DISTINCT, LIMIT, BETWEEN, IN⦁ Aliasing (AS)
2. Filtering & Aggregation
⦁ GROUP BY & HAVING⦁ COUNT(), SUM(), AVG(), MIN(), MAX()
⦁ NULL handling with COALESCE, IS NULL
3. Joins
⦁ INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN
⦁ Joining multiple tables
⦁ Self Joins
4. Subqueries & CTEs
⦁ Subqueries in SELECT, WHERE, FROM
⦁ WITH clause (Common Table Expressions)
⦁ Nested subqueries
5. Window Functions
⦁ ROW_NUMBER(), RANK(), DENSE_RANK()
⦁ LEAD(), LAG()
⦁ PARTITION BY & ORDER BY within OVER()
6. Data Manipulation
⦁ INSERT, UPDATE, DELETE
⦁ CREATE TABLE, ALTER TABLE
⦁ Constraints: PRIMARY KEY, FOREIGN KEY, NOT NULL
7. Optimization Techniques
⦁ Indexes
⦁ Query performance tips
⦁ EXPLAIN plans
8. Real-World Scenarios
⦁ Writing complex queries for reports
⦁ Customer, sales, and product data
⦁ Time-based analysis (e.g., monthly trends)
9. Tools & Practice Platforms
⦁ MySQL, PostgreSQL, SQL Server
⦁ DB Fiddle, Mode Analytics, LeetCode (SQL), StrataScratch
10. Portfolio & Projects
⦁ Showcase queries on GitHub
⦁ Analyze public datasets (e.g., ecommerce, finance)
⦁ Document business insights
