Live PostgreSQL syntax checking for ```sql code blocks in Markdown files.
Errors show up as red squiggles as you type, exactly like any other linter — powered by
libpg_query, the actual PostgreSQL parser
extracted from the server source (the same library behind the pg_query Ruby gem).
That means the error messages match what psql would tell you, with accurate line and
column positions.
Why
Course material, homework assignments, and documentation sometimes embed SQL in Markdown
code fences. Every SQL linter we could find wants a .sql file
(SQLFluff explicitly declined markdown support),
and "inline SQL" extensions target strings inside Python/Go/JS — not Markdown.
This extension fills that gap.
Features
Lints every ```sql / ```postgresql / ```pgsql fence on open and as you type (debounced)
Real PostgreSQL syntax errors with exact positions, squiggle on the offending token
Heuristic Hint: lines for common mistakes — trailing comma before FROM, keyword
typos (SELEC → "Did you mean SELECT?"), unclosed parentheses, reserved words used
as table names
Multi-statement blocks supported
Pure-WASM parser bundled with the extension — no Python, no database, nothing to install
~~~ fences, longer fence markers, and case-insensitive info strings all handled
Settings
Setting
Default
Description
markdownSqlLint.enable
true
Master switch
markdownSqlLint.fenceLanguages
["sql", "postgres", "postgresql", "pgsql"]
Fence info strings treated as SQL
markdownSqlLint.debounceMs
300
Idle delay before re-linting
Limitations (by design, for now)
Syntax only.SELECT * FROM tabel_with_typo parses fine — the parser can't know
your schema. Semantic checks (unknown table/column) would need a live database; planned
as an opt-in feature.
One error per block. The parser stops at the first syntax error in a block
(subsequent blocks are still checked independently).
PostgreSQL dialect. MySQL/SQLite-specific syntax will be flagged. Other dialects
would need a different parser backend.
Contributing
Bug reports, hint heuristics, and dialect ideas welcome — see CONTRIBUTING.md
in the repository for setup and the extension-testing workflow.
