Tutorial
Hands-on walkthroughs for SQL, Python, Excel and visualisation tools — every example is runnable, not a screenshot.
119 articles in Tutorial · Page 1 of 14
Power BI + GenAI Analyst Workflows
Insight briefs, GenAI QA loops, stakeholder self-serve pages: the 3 systems that get analysts promoted, with build steps and success metrics.
Nested Query to CTE in 4 Steps
Turn a 3-level nested subquery into a readable CTE interviewers can maintain at 2am: a 4-step refactor worksheet with before-and-after SQL code.
Excel to SQL: Full Translation Map
VLOOKUP to JOIN, PivotTables to GROUP BY, filters to WHERE: every Excel skill mapped one-to-one to SQL, with a live practice path included inside.
SQL Date Functions Guide: Practical Examples (2026)
Master sql date functions with practical examples. Learn DATE_TRUNC, EXTRACT, interval rolling windows, and how to avoid the timestamp BETWEEN trap.
Window Functions in SQL: Practical Guide & Examples
Master window functions in sql with practical examples. Learn OVER, PARTITION BY, running totals, rankings, and lead lag calculations step by step.
How to Use Leetcode Alternatives: Complete Guide & Examples
Master how to use LeetCode alternatives to solve real-world SQL and Python problems. Explore hands-on platforms, code walkthroughs, and error fixes.
Understanding Null Semantics In Sql: 2026 Guide & Examples
Master three-valued logic and traps by understanding null semantics in sql. Learn NOT IN pitfalls, WHERE vs HAVING filtering, and safe COALESCE math.
Full Outer Join In Sql: 2026 Guide & Examples
Master the full outer join in sql with practical examples, billing reconciliation queries, syntax rules, and NULL handling for data analysts.
LEFT JOIN vs LEFT OUTER JOIN in SQL: Key Differences
Is there any difference between LEFT JOIN and LEFT OUTER JOIN in SQL? Learn ANSI syntax rules, performance benchmarks, and common WHERE clause traps.