sqllens SQL

Multi-dialect SQL language support for VS Code, powered by the sqllens analyzer via sqllens-language-server. Fully self-contained: the language server is bundled with the extension, so installing it is the only step.

Source-first and semantics-first: SQL is understood statically, across ten real dialects, without a database connection.

Features

• Diagnostics: positioned syntax errors plus semantic errors (unknown table/column/field) when a schema catalog is configured.
• Typed hover (with nullability where provable), go-to-definition, find references, document highlight, document symbols, code lens.
• Scope-aware completion (works mid-edit), signature help, inlay hints, semantic highlighting, folding and selection ranges.

Dialects: databricks, tsql, snowflake, bigquery, redshift, postgres, duckdb, trino, sqlite, mysql.

Configuration: .sqllens.json

Optional, at the workspace root. Maps files to dialects (first match wins) and points at a schema catalog that switches on the semantic tier:

{
	"dialects": [{ "files": "tsql/**/*.sql", "dialect": "tsql" }],
	"default": "duckdb",
	"schema": "schema.json"
}

schema.json is a plain { "table": { "column": "type" } } catalog. Without any config, files fall back to the databricks dialect and the syntax tiers still work.

No config file at all? The language picker doubles as a dialect picker: set a file (or a files.associations glob) to "SQL (DuckDB)", "SQL (BigQuery)", ... and that binds its dialect directly.

Plugins

JavaScript plugins declared in .sqllens.json add live schema catalogs and custom diagnostics/hover/completion hooks; tutorial in PLUGINS.md.

Feedback

Issues and suggestions: GitHub issues.

Development

This folder is a self-contained sub-package of the sqllens-language-server repo:

npm install
npm run build        # tsc → dist/
npm run package      # vsce → .vsix

The bundled server version is pinned by this package's dependency on sqllens-language-server; extension releases mirror server releases.

License

MIT