SQL Lesson 1: SELECT — Reading Data
Your first SQL queries: what tables, rows and columns are, install DB Browser for SQLite, SELECT columns, SELECT *, calculated columns with AS, DISTINCT…
Read article →Coding
Start-to-finish programming for people who work with data: Python, SQL, Java, R, JavaScript, Rust and PowerShell.
Why Learn Rust? Your First Rust Program, Explained for Beginners
Why Learn Rust? Your First Rust Program, Explained for Beginners
What makes Rust different — speed without crashes — and a gentle walk through your first program: variables, ownership, and a tiny CSV-style summary.
Read article →What Is an API? A Plain-English Guide With a Real Example
What Is an API? A Plain-English Guide With a Real Example
APIs explained with a restaurant analogy, then a real example: fetch exchange rates with a URL, read the JSON, and pull it into Excel…
Read article →R Lesson 4: dplyr — filter, mutate, summarise
R Lesson 4: dplyr — filter, mutate, summarise
Analyse data with dplyr verbs: filter rows, mutate new columns, arrange, group_by and summarise — the R equivalent of filters, formulas and pivot tables.
Read article →SQL from Zero: A Complete Beginner’s Guide (with Practice)
SQL from Zero: A Complete Beginner’s Guide (with Practice)
Learn SQL from the very beginning: tables, SELECT, WHERE, ORDER BY, aggregates, GROUP BY, JOINs, NULLs, subqueries, CTEs, window functions and changing data —…
Read article →SQL for Excel Users: 10 Queries That Replace Everyday Excel Work
SQL for Excel Users: 10 Queries That Replace Everyday Excel Work
Learn SQL through tasks you already do in Excel — filters, sorting, pivot tables, VLOOKUP and remove duplicates — with 10 queries you can…
Read article →Google Sheets QUERY Function for Excel Users
Google Sheets QUERY Function for Excel Users
Google Sheets’ QUERY function lets you filter, group and sort with SQL-like syntax in one formula. Learn it with examples mapped to Excel features…
Read article →SQL Window Functions: Running Totals, Rankings and Month-on-Month in One Query
SQL Window Functions: Running Totals, Rankings and Month-on-Month in One Query
A practical guide to SQL window functions: OVER and PARTITION BY, ROW_NUMBER, RANK and DENSE_RANK, running totals, moving averages, LAG/LEAD for month-on-month change, and…
Read article →Docker for Beginners: Run Any App Without Installing It
Docker for Beginners: Run Any App Without Installing It
What containers are, why “works on my machine” disappears, and your first Docker commands — run a database, a Jupyter notebook and your own…
Read article →JSON Explained Simply (for Excel People)
JSON Explained Simply (for Excel People)
What JSON is, how to read it, how it maps to rows and columns, and how to load JSON into Excel with Power Query…
Read article →Java Lesson 8: Project — An Invoice Calculator
Java Lesson 8: Project — An Invoice Calculator
Bring it together: an Invoice class with validated lines, GST calculation, item summaries with a Map and formatted output, plus next steps (Maven, Apache…
Read article →Java Lesson 7: Exceptions and Files
Java Lesson 7: Exceptions and Files
Handle errors with try/catch/finally, throw meaningful exceptions, and read and write text files with java.nio.file.Files.
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