Tutorial
Hands-on walkthroughs for SQL, Python, Excel and visualisation tools — every example is runnable, not a screenshot.
109 articles in Tutorial · Page 6 of 13
SUM Formula in Excel: AutoSum, Ranges, and 3D Sheet Sums (with Examples)
Master the sum formula in excel: learn syntax, AutoSum shortcut Alt + =, multi-range additions, 3D sheet sums, and troubleshooting silent errors.
Tableau Complete Guide: Master Business Intelligence and Dashboards (2026)
Master Tableau for business intelligence: data connections, visual analytics, calculated fields, LOD expressions, table calculations, and interactive dashboards.
Transpose Excel: How to Switch Rows and Columns (Formula & Shortcut)
Learn how to transpose excel data: switch rows to columns using Paste Special Transpose, the dynamic =TRANSPOSE() formula, and Power Query.
How to Unhide Columns in Excel: 5 Methods (with Shortcuts)
How to unhide columns in Excel: drag headers, right-click Unhide, Ctrl+Shift+0, Go To Special, and fixes for columns that refuse to reappear. Full guide.
VLOOKUP Formula in Excel: Syntax, Step-by-Step Guide, and Common Fixes
Master the vlookup formula in excel: understand all 4 arguments, build exact lookups, fix #N/A errors, and compare with XLOOKUP and INDEX MATCH.
What Is SQL? The Complete Beginner to Pro Database Guide (2026)
What is SQL? Learn how Structured Query Language works, relational database concepts, SELECT queries, JOINs, DDL vs DML commands, and analyst workflows.
XLOOKUP Formula in Excel: Syntax, Examples, and VLOOKUP Migration
XLOOKUP formula in Excel explained: syntax, exact match, reverse lookup, and if_not_found. Real examples plus VLOOKUP migration tips for analysts daily.
Connect VS Code to PostgreSQL with SQLTools (Step-by-Step)
Connect Visual Studio Code to PostgreSQL using SQLTools in 4 steps: install drivers, configure host/port credentials, fix search_path errors, and run queries.
A/B Testing in Python: Sample Size, Hypothesis Testing & P-Value Analysis
Complete A/B testing guide for data analysts in Python. Calculate sample sizes with statsmodels, detect Sample Ratio Mismatch (SRM), run proportion z-tests and Welch's t-tests, and avoid the peeking problem.