How to Auto-Generate Documentation from a CREATE TABLE Statement

Most teams have a schema documentation page somewhere — a Confluence page, a wiki, a README — and most of those pages are at least a little wrong, because updating them is a separate manual step from actually running a migration. The migration ships; the doc doesn't, until someone notices during onboarding or debugging that they don't match.

The actual source of truth is already the SQL

A CREATE TABLE statement already contains everything a documentation page is trying to describe: column names and types, which columns are nullable, default values, primary keys, and foreign key relationships to other tables. Generating docs directly from that statement — instead of maintaining a separate prose description of it — means the documentation can't drift from reality between updates, because there's nothing to keep in sync by hand.

What good generated documentation should include

• Every column, with its type, nullability, and default value — the same questions someone new to the table would otherwise have to ask in a chat thread.
• Primary and foreign keys, so relationships between tables are explicit rather than something you have to infer from column naming conventions.
• An ER diagram, since a visual map of how tables connect is usually faster to orient with than reading several CREATE TABLE statements in sequence — especially useful for onboarding someone new to a schema with a dozen-plus tables.

Keeping it from going stale again

Auto-generating docs from schema solves the "nobody updated the wiki" problem, but it introduces a smaller version of the same question: when do you regenerate? Two patterns work well in practice:

• Regenerate and re-paste the updated schema as part of the same PR that changes it — treat "update the docs" as a checklist item on any migration, not a separate task that can be forgotten.
• Keep it a five-minute manual step (paste current schema in, publish the output) rather than trying to fully automate it into CI immediately — a lightweight habit that actually happens beats an automated pipeline that never gets built.

Paste your schema below

Schema Docs below takes your CREATE TABLE statements and generates readable documentation — column details, table descriptions, and an ER diagram — directly from the SQL, with nothing uploaded anywhere.