Postgres Language Server

A Language Server for Postgres. Not SQL with flavors, just Postgres.

Warning

This is in active development and is only ready for collaborators. But we are getting there! You can find the current roadmap and opportunities to contribute in #136.

Features

The Language Server Protocol is an open protocol between code editors and servers to provide code intelligence tools such as code completion and syntax highlighting. This project implements such a language server for Postgres, significantly enhancing the developer experience within your favorite editor by adding:

• Lint
• Hover
• Typechecking
• Syntax Error Diagnostics
• Inlay Hints
• Auto-Completion
• Code actions such as Execute the statement under the cursor, or Execute the current file
• Formatter
• ... and many more

We plan to support all of the above for SQL and PL/pgSQL function bodies too!

Motivation

Despite the rising popularity of Postgres, support for the PL/pgSQL in IDEs and editors is limited. While there are some generic SQL Language Servers¹ offering the Postgres syntax as a "flavor" within the parser, they usually fall short due to the ever-evolving and complex syntax of PostgreSQL. There are a few proprietary IDEs² that work well, but the features are only available within the respective IDE.

This Language Server is designed to support Postgres, and only Postgres. The server uses libpg_query, therefore leveraging the PostgreSQL source to parse the SQL code reliably. Using Postgres within a Language Server might seem unconventional, but it's the only reliable way of parsing all valid PostgreSQL queries. You can find a longer rationale on why This is the Way™ here. While libpg_query was built to execute SQL, and not to build a language server, any shortcomings have been successfully mitigated in the parser crate. You can read the commented source code for more details on the inner workings of the parser.

Once the parser is stable, and a robust and scalable data model is implemented, the language server will not only provide basic features such as semantic highlighting, code completion and syntax error diagnostics, but also serve as the user interface for all the great tooling of the Postgres ecosystem.

Installation

Warning

This is not ready for production use. Only install this if you want to help with development.

Note

Interested in setting up a release process and client extensions for Neovim and VS Code? Please check out #136!

Neovim

Add the postgres_lsp executable to your path, and add the following to your config to use it.

local util = require 'lspconfig.util'
local lspconfig = require 'lspconfig'

require('lspconfig.configs').postgres_lsp = {
  default_config = {
    name = 'postgres_lsp',
    cmd = { 'postgres_lsp' },
    filetypes = { 'sql' },
    single_file_support = true,
    root_dir = util.root_pattern 'root-file.txt',
  },
}

lspconfig.postgres_lsp.setup { force_setup = true }

Building from source

You'll need nightly Cargo, Node, and npm installed.

Install the libpg_query submodule by running:

git submodule update --init --recursive

If you are using VS Code, you can install both the server and the client extension by running:

cargo xtask install

If you're not using VS Code, you can install the server by running:

cargo xtask install --server

The server binary will be installed in .cargo/bin. Make sure that .cargo/bin is in $PATH.

Github CodeSpaces

Currently, Windows does not support libpg_query. You can setup your development environment on CodeSpaces.

After your codespace boots up, run the following command in the shell to install Rust:

curl --proto '=https' --tlsv1.2 https://sh.rustup.rs -sSf | sh

Proceed with the rest of the installation as usual.

Contributors

• psteinroe (Maintainer)

Footnotes

Footnotes

1. Generic SQL Solutions: sql-language-server, pgFormatter, sql-parser-cst ↩

2. Proprietary IDEs: DataGrip ↩