How to contribute

Error Reports

Please report any issue to the GitHub Issue Tracker:

  1. Provide the Sample SQL (shortened and simplified, properly formatted)

  2. State the exact Version of JSQLParser

  3. State the RDBMS in use and point on the applicable Grammar specification

  4. Please write in English and post Plain Text only (avoiding screen shots or bitmap pictures).

Before reporting any issues, please verify your statement using JSQLFormatter Online.

Feature Requests

JSQLParser is a demand-driven software library, where many contributors have shared solutions for their own needs. Requests for new features have a good chance to get implemented when

  1. the request is about a commonly used feature for one of the major RDBMS

  2. or the request is backed by a sponsor or a bounty, which may attract developers to spend their time on it.

Implementing new Features

The team around JSQLParser warmly welcomes Code Contributions and Pull Requests. Please follow the guidance below and do not hesitate to ask us for assistance.

Create a new Git Branch

When starting afresh, clone JSQLParser from the GitHub repository:

git clone
cd JSqlParser
git branch <new-branch>

When having a local repository already, then pull/merge from the GitHub repository:

cd JSqlParser
git pull origin master
git branch <new-branch>

Amend the Code

The JSQLParser is generated by JavaCC based on the provided Grammar. The Grammar defines how a SQL Text is read and translated into Java Objects. Thus any contribution will depend on the following steps:

  1. Edit the JavaCC Grammar at src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

  2. Add or edit the Java Classes at src/main/java/net/sf/jsqlparser to facilitate this Grammar.

  3. When have added new Java Classes, amend the Visitors, the Visitor Adaptors, the De-Parsers and the Validators.

  4. Provide Java Unit Tests at src/test/java/net/sf/jsqlparser to test the new feature

    • The test should call at least one time the method assertSqlCanBeParsedAndDeparsed()

    • The test should ensure complete coverage of the new Java Classes.

    • The complete test suite must succeed.

  5. Add the description of the new feature to the file, section Extensions.

  6. Build the package with Maven and ensure, all checks do pass (PMD and CheckStyle and Code Formatting).

Manage Reserved Keywords

Since JSQLParser is built by JavaCC from a Token based Grammar, Reserved Keywords need a special treatment. All Tokens of the Grammar would become Reserved Keywords – unless explicitly allowed and white-listened.

White-list Keyword example
-- <K_OVERLAPS:"OVERLAPS"> is a Token, recently defined in the Grammar
-- Although it is not restricted by the SQL Standard and could be used for Column, Table and Alias names
-- Explicitly white-listing OVERLAPS by adding it to the  RelObjectNameWithoutValue() Production will allow for parsing the following statement

SELECT Overlaps( overlaps ) AS overlaps
FROM overlaps.overlaps overlaps
WHERE overlaps = 'overlaps'

So we will need to define and white-list any Keywords which may be allowed for Object Names (such as Schema, Table, Column, Function, Alias). This White-List must be updated whenever the Tokens of the Grammar change (e. g. when adding a new Token or Production).

There is a task updateKeywords for Gradle and Maven, which will:

  1. Parse the Grammar in order to find all Token definitions

  2. Read the list of explicitly Reserved Keywords from net/sf/jsqlparser/parser/

  3. Derive the list of White-Listed Keywords as difference between All Tokens and Reserved Keywords

  4. Modifies the Grammar Productions RelObjectNameWithoutValue... adding all Tokens according to White-Listed Keywords

  5. Run two special Unit Tests to verify parsing of all White-Listed Keywords (as Schema, Table, Column, Function or Alias)

  6. Update the web page about the Reserved Keywords

Gradle updateKeywords Task
    gradle updateKeywords
Maven updateKeywords Task
    mvn exec:java

Without this Gradle Task, any new Token or Production will become a Reserved Keyword automatically and can’t be used for Object Names without quoting.

Commit a Pull Request

cd JSqlParser
git add -A
git commit -m <title> -m <description>
git push –set-upstream origin <new-branch>

Follow the advice on Meaningful Commit Messages and consider using Commitizen when describing your commits.

Please consider using Conventional Commits and structure your commit message as follows:

Conventional Commit Message Structure
<type>[optional scope]: <description>

[optional body]

[BREAKING CHANGE: <change_description>]

[optional footer(s)]
Commit Message Types




introduce a new feature


patches a bug in your codebase (bugfix or hotfix)


changes that affect the build system or external dependencies


updates dependencies and does not relate to fix or feat and does not modify src or test files.


changes that affect the continuous integration process


updates the documentation or introduce documentation


updates the formatting of code; remove white spaces, add missing spaces, remove unnecessary newlines


reactors code segments to optimize readability without changing behavior


improve performance


add/remove/update tests


reverts one or many previous commits

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