ExcelGuide
Excel Security Problems Developers Overlook in Pipelines
Excel risks a data pipeline inherits: formula injection, macros, zip bombs, XML entity attacks, hidden data and weak passwords, with the checks for each.
17 min read
Library
Everything you need to level up your coding skills.
JSON
Flattening Nested JSON With LATERAL FLATTEN in Snowflake
Use FLATTEN in Snowflake to turn VARIANT arrays and objects into rows, chain it for nested levels, keep empty parents with OUTER, and read its output columns.
6 min read
CSV
Reading a CSV File in C Sharp With CsvHelper Correctly
Read CSV in C# with CsvHelper 33: case-sensitive headers, typed ZIP codes, silent ragged rows, and a de-DE culture that made a total 91 times too big.
10 min read
XML
Choosing XML Element Names and Casing That Hold Up
XML names are case sensitive and follow strict character rules. Compare camelCase, snake_case and kebab-case for elements, with the rules that decide.
5 min read
YAML
Why Loading Untrusted YAML Can Run Code and How to Stop It
How a YAML tag makes a loader build arbitrary objects, with a harmless proof in PyYAML, what safe_load and full_load did with it, and Ruby and Java behavior.
6 min read
Excel
Converting Excel to CSV for Every Sheet in a Workbook
Export every sheet of an Excel workbook to its own CSV with pandas, openpyxl or LibreOffice, with safe file names, UTF-8, ISO dates and a manifest.
8 min read
CSV
Parsing CSV in Rust With the csv Crate and Serde Types
Parse CSV in Rust with the csv crate: StringRecord, ByteRecord and serde, UnequalLengths errors, typed ZIP codes and an unclosed quote it accepts.
9 min read
PostgreSQL
Nested Loop Hash Join and Merge Join Compared in Plans
Nested loop, hash join and merge join compared in PostgreSQL: how each works, cost shape, memory and batches, plan clues and fixes when the choice is wrong.
7 min read
JSON
Querying VARIANT Columns With Colon Syntax in Snowflake
Read JSON stored in a Snowflake VARIANT column with colon and bracket paths, cast the results, and handle JSON null, missing keys and case sensitivity.
7 min read
XMLGuide
Designing XML Documents That Age Well From Day One
A practical guide to XML format design: names, attributes, lists, optional data, binary, namespaces and versions, with a tested worked example.
19 min read
CSV
Reading CSV Files in R With readr and fread Safely
Compare read_csv, fread and base read.csv on the same files: type guessing and ZIP codes, ragged rows, bad quotes, the BOM, and speed on 2,000,000 rows.
10 min read
ExcelGuide
Converting Excel to CSV JSON XML and YAML in Practice
Convert Excel workbooks to CSV, JSON, XML and YAML without losing data: choose a format, read types, dates and headers, then verify with counts and schemas.
17 min read
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