This repo is a sandbox, not a product. It was written as a trial-and-error exercise to learn how to build a JQL-style query DSL — lexer, parser, AST visitor, and SQL compilation — before taking on the real implementation. Expect incomplete features and a few dead ends.

The "real thing" will be built as a separate project, informed by what was learned here.

• How to design a small grammar and express it with Chevrotain (tokens, CST parser rules, visitors).
• How to turn a parsed tree into an intermediate representation that a downstream compiler can consume.
• How to wire that into TypeORM and go from parsed query → executable SQL.
• How to auto-generate entity classes from a live database schema.

(Entity prop operator value) [And|Or (Entity prop operator value) ...]

Examples:

(User age > 18)
(User gender = "F") And (User age > 18)

Flow:

input string
  → lexer (Chevrotain tokens)
  → parser (CST)
  → visitor (normalized IR)
  → query builder (SQL string)

• Tokenizing and parsing the grammar above.
• Visiting the CST into a flat list of VisitedStatements joined by conjunctions.
• Compiling that list into a SELECT * FROM <entity> WHERE … string.
• Validating entity and property names against a supplied metadata map.
• Generating TypeORM entity classes from a database via typeorm-model-generator.

npm install
npm test          # Jasmine suite
npm run dev       # Nodemon on src/index.ts
npm run tsc       # Type-check + build to main/

Configure .env:

HOST=localhost
DB_NAME=my_db
USER_NAME=my_user
PASSWORD=***
DB_TYPE=mysql
OUTPUT_PATH=./src/lib/ORM/

Then:

npm run generate-types

src/
├── index.ts
└── lib/
    ├── lexer/       # Chevrotain tokens
    ├── parser/      # CST parser rules
    ├── visitor/     # CST → IR
    └── ORM/
        ├── db-connector/    # TypeORM DataSource factory
        ├── query-builder/   # IR → SQL
        ├── entities/        # Generated entity classes
        └── scripts/         # generate-types.js

• FilterManager — part one, the consumer of the DSL this branch was exploring.

Archived as a reference. The production implementation lives elsewhere (or will). Please don't depend on this package.