XMLGuide
XML Security Problems to Close Before Production Launch
The XML attacks that matter for web services and loaders, how six parsers behave, one parse function with limits, and the tests that keep it closed.
18 min read
Tag
hub
102 posts
ExcelGuide
Understanding Excel Errors When Data Comes From Code
A map of Excel errors seen when scripts write or read workbooks: file and format messages, cell error codes, library exceptions and a debugging order.
19 min read
XMLGuide
Common XML Formats You Will Meet in Real Work Reference
A reference to the XML formats you meet in practice: how to recognize each by root and namespace, what to extract, and the trap each one carries.
19 min read
Editor's pick
CSVGuide
Querying CSV Files With DuckDB Instead of Loading Them
DuckDB runs SQL on a CSV file with no import, no schema and no server. See what it guesses, what that costs, where it fails, and how to make it strict.
22 min read
JSONGuide
Using the JSON Column Type in MySQL Without Regret
A working guide to MySQL 8.4 JSON columns: paths, reading, updating, searching, generated-column and multi-valued indexes, and MariaDB differences.
19 min read
XMLGuide
Analysis on XML Data When Nobody Has Converted It Yet
A method for questions about an XML file nobody has converted: look, profile, sample, pick a tool, answer, then prove the numbers with a second method.
17 min read
ExcelGuide
Pivot Tables and Their SQL Equivalents for Excel Users
For people who know Excel pivot tables and need the SQL behind them: GROUP BY, conditional aggregates, ROLLUP, window functions, unpivoting and checks.
19 min read
YAMLGuide
Structuring YAML Configuration Files That Last for Years
How to lay out YAML config so it stays correct: base and overlays, secret references, a schema, strict loading, key style, comments and a CI check, tested.
17 min read
Editor's pick
CSVGuide
Importing CSV Files Into SQLite From the Command Line
The sqlite3 .import command loads a CSV in seconds and reports problems as warnings with exit status zero. Import safely with types, checks and a swap.
20 min read
YAMLGuide
Working With YAML From the Terminal Using yq and Friends
A tested command-line guide to YAML: query, edit, merge, convert, lint, validate and diff with yq, yamllint and check-jsonschema, plus the traps found.
20 min read
XMLGuide
Validating XML Against an XSD Schema Step by Step Guide
How to check XML files against an XSD: write the schema, run xmllint and lxml, read the errors, add Schematron for business rules, and test changes safely.
18 min read
YAMLGuide
Reading and Writing YAML in Python Safely and Cleanly
A tested Python guide to YAML: safe loading, speed, strict keys, validation, clean output, round trips, merging, env substitution and a reference module.
20 min read