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
Library
Everything you need to level up your coding skills.
XML
Converting CSV to XML With a Template That Escapes Correctly
Build XML from CSV rows without string templates that break on an ampersand. Use lxml or escape every value, and handle control characters and empty cells.
7 min read
Excel
IF and IFS Versus CASE WHEN in SQL Compared Side by Side
Translate IF, nested IF, IFS and SWITCH into SQL CASE WHEN, with AND and OR, NULL handling, branch types and what each returns when nothing matches.
7 min read
JSON
Adding and Removing Keys From JSONB With jsonb_set and Minus
Add, rename, merge and delete keys and array elements in PostgreSQL JSONB with jsonb_set, jsonb_insert, || and minus, and see where each does nothing.
8 min read
CSV
MySQL Error 1290 The Server Is Running With secure file priv
Error 1290 blocks LOAD DATA INFILE and INTO OUTFILE outside one directory. Find the allowed path, move the file there, or switch to LOCAL and know the cost.
6 min read
Excel
COUNTIF Versus COUNT With a Filter in SQL Compared
Translate COUNTIF, COUNTIFS, COUNTA and COUNTBLANK into SQL with count star, count of a column and FILTER, and handle distinct counts and blanks correctly.
6 min read
CSV
Using LOAD DATA INFILE to Import a CSV Into MySQL Tables
Every clause of LOAD DATA INFILE that matters for a CSV, from the tab default to NULL handling, with the output of each variant on MySQL 8.4.
7 min read
XML
Converting XML to YAML for Config Review and What It Breaks
Convert an XML config to YAML so a person can read and diff it, and learn why a YAML 1.1 loader turns the strings no and NO into false and 0755 into 493.
7 min read
JSON
Updating One Key Inside a JSONB Column Without Losing Data
Change a single field in a PostgreSQL JSONB document with jsonb_set or subscripts, increment a counter, and avoid the lost-update and rewrite costs.
8 min read
Editor's pick
CSVGuide
How to Import a CSV File Into MySQL the Reliable Way
LOAD DATA LOCAL turns bad values into warnings and still reports success. Import a CSV into MySQL safely, with a script that checks before it swaps.
23 min read
YAML
Finding Tab Characters Hiding in a YAML File Quickly
Find tabs and non-breaking spaces in YAML with grep, cat -A and git grep, fix them with sed or expand, and keep them out with editor settings and a hook.
6 min read
Excel
SUMIF and SUMIFS Versus GROUP BY in SQL Compared in Depth
Translate SUMIF and SUMIFS into SQL with WHERE, GROUP BY and FILTER, including criteria, wildcards, dates, OR conditions and the blank and case traps.
7 min read
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