How to parse / tokenize an SQL statement in Node.js

Yves M. picture Yves M. · Aug 6, 2014 · Viewed 13.4k times · Source

I'm looking for a way to parse / tokenize SQL statement within a Node.js application, in order to:

  • Tokenize all the "basics" SQL keywords defined in the ISO/IEC 9075 standard or here.
  • Validate the SQL syntax.
  • Find out what the query is gonna do (e.g. read or write?).

Do you have any solution or advises peeps?

Linked: Any Javascript/Jquery Library To validate SQL statment?


I've done research and I found out some ways to do it:

Using existing node.js libraries

I did a Google search and I didn't found a consensual and popular library to use. I found those ones:

  • simple-sql-parser (22 stars on github, 16 daily download on npm)
    • Supports only SELECT, INSERT, UPDATE and DELETE
    • There is a v2 branch on the road
  • sql-parser (90 stars on github, 6 daily downloads on npm)
    • Only supports basic SELECT statements
    • Based on jison
  • sqljs (17 stars on github, 5 daily downloads on npm)
    • v0.0.0-3, under development... No documentation at all :)

Unfortunately, none of those libraries seams to be complete and trustful.

Doing it myself based on a node.js low level tokenizer library

I can do it my self with a low level tokenizer library like:

Doing it myself based on existing Javascript code beautifier

CodeMirror is a pretty cool Javascript library (browser side) that can recognize SQL keywords, strings, etc. Check ou the demo.

I can build a node.js library tokenizer based on CodeMirror. The SQL mode is here on github, I can maybe adapt it to get tokens within a node application.

PS: CodeMirror have 5,046 stars on github and is well maintained.


I figured out that there are 2 distinct problems: Tokenization and Syntax validation (which is related to tokenization).

I made myself a SQL tokenizer for Node.js based on the SQL mode of the excellent CodeMirror (5,046 stars on github, well maintained). CodeMirror's SQL mode take in charge "generic" SQL and some SQL particularities like MSSQL, MySQL, PL/SQL, Cassandra, Hive and MariaDB.

When my project will be mature enough, I will (probably) put it public on GitHub and let you know.

About the SQL syntax validation, I found no JavaScript tool (or open source project to adapt in JS) yet...

Answer

aleclarson picture aleclarson · Aug 11, 2018

I recently published the sql-ast package, which parses SQL scripts and returns an array of AST nodes. (I couldn't find anything similar that's maintained)

It's very limited at the moment. I've only implemented what I need from it. If you have time, please contribute. I've tried hard to make the codebase understandable.

Give it a star if you're interested in seeing it developed further. I will update this answer as the library is improved.