JSON
JSON Columns and Schema Drift and How to Find It Early
Measure schema drift in a jsonb column with key counts and type counts, see how it changes a sum, and stop it with a NOT VALID check constraint.
6 min read
Tag
quality
52 posts
CSV
Logging Rejected Rows From a CSV Import for Review
Capture every row an import refuses, with its line, column and reason, in a form a person can fix and replay. A DuckDB example with real reject tables.
6 min read
Excel
Giving Users a Template Instead of Rules for Uploads
Replace a page of upload rules with a ready template: built-in formats, dropdowns, an example row, a stable link and a note on what the file is for.
7 min read
Excel
Rejecting Files That Do Not Match the Template Cleanly
Reject Excel files that do not match the template in a way senders can act on: staged checks, stable codes, specific messages, quarantine and a retry path.
7 min read
Excel
Versioning Template Layouts So Old Files Still Import
Version Excel template layouts so the loader recognizes old files: a version cell, compatible changes, migration rules, a support window and a changelog.
8 min read
Excel
Reserving Notes in a Separate Sheet of Import Templates
Give notes, comments and instructions their own place in an import template so the data sheet stays a clean table, and make the loader ignore strays.
7 min read
Excel
Data Types per Column in Templates That Feed a Database
Map Excel template columns to database types: text for identifiers, real dates, fixed-decimal numbers, flags and lists, with validation and checks.
7 min read
Excel
Naming Sheets and Columns for Machines in Excel Templates
Name sheets and columns in Excel templates so code and databases can use them: lowercase snake case, no punctuation, stable keys, label mapping.
7 min read
Excel
One Header Row and No Merged Cells in Import Templates
Why import templates need one header row and no merged cells, how to detect both in code, and how to repair files that arrive with titles and merged headings.
7 min read
YAML
Documenting Datasets in YAML and Catching Schema Drift
Describe a dataset in YAML, render a Markdown table from it and compare it with the live table to catch columns added or dropped without a doc.
6 min read
ExcelGuide
Building Excel Templates That Import Cleanly Every Time
Design Excel templates that load into a database without cleanup: one header row, machine names, typed columns, a notes sheet, versions and rejection rules.
17 min read
JSON
Versioning a JSON Schema Without Breaking Consumers
Which schema changes break old producers and old consumers: a tested compatibility matrix, open versus closed objects, version numbers and a CI check.
8 min read