SQL & Databases — Data Science Roadmap
The primary language for pulling and shaping data before any analysis happens
Steps in SQL & Databases
- SQL Fundamentals (SELECT, WHERE, ORDER BY) — beginner · Querying and filtering rows from a single table
- Joins & Set Operations — beginner · Combining data across tables with INNER/LEFT/RIGHT/FULL joins, UNION and INTERSECT
- Aggregations & GROUP BY — beginner · Summarizing data with COUNT, SUM, AVG and grouping rows into categories
- Window Functions — intermediate · Running totals, rankings and row-by-row comparisons without collapsing rows
- Subqueries & CTEs — intermediate · Breaking complex queries into readable, composable pieces
- Database Design Basics — beginner · Primary/foreign keys, normalization and how schemas are structured
- NoSQL Databases Overview — intermediate · Document, key-value and columnar databases, and when they fit better than SQL
- Query Performance for Analysts — intermediate · Reading a query plan and understanding why a query is slow
Part of
- Data Science roadmap — the full learning path