Query

A powerful JS library that provides a robust and fluent interface to build, parse, and execute queries. Designed with the principles of modularity, the library consists of a collection of classes that work in unison to create complex query expressions, translate them into an Abstract Syntax Tree (AST), and execute them.

Features

• Supports Various Query Operations: like $eq, $gt, $lte, $in, etc.
• Extensible: Incorporate OOP principles and design patterns.
• Fluent API: Chainable methods for intuitive query building.
• Customizable: Use the Factory to replace or extend the built-in classes.

Installation

Install the package with:

npm install @basd/query

Usage

First, import the Query library.

import Query from '@basd/query'

or

const Query = require('@basd/query')

Create a new Query

const query = new Query({
  // Optional configurations...
})

Build a Query

Using the QueryBuilder class:

const builder = new QueryBuilder()
builder.where('age').gte(18).and().lt(30)
const resultQuery = builder.build()

Parsing a Query

Once you have a built query, use QueryParser to parse it:

const parser = new QueryParser()
const parsed = parser.parse(resultQuery)

Interpreting a Query

Execute a parsed query using the QueryInterpreter:

const interpreter = new QueryInterpreter()
const result = interpreter.interpret(parsed, yourEntity)

Using the Query Engine

To perform database operations like refine, filter, and find:

const engine = new QueryEngine()
engine.find({ age: { $gte: 18, $lt: 30 } })

Documentation

• API Reference

Classes

• Query: Main class to manage query building, parsing, and execution.
• QueryBuilder: Helps construct query objects in a fluent manner.
• QueryParser: Transforms a query object into an abstract syntax tree.
• QueryInterpreter: Evaluates an entity against the parsed query.
• QueryVisitor: Visit AST nodes to evaluate them against an entity.
• QueryFactory: Factory for creating instances of other classes.
• QueryEngine: Provides higher-level database operations.

Tests

In order to run the test suite, simply clone the repository and install its dependencies:

git clone https://gitlab.com/frenware/framework/plaindb/query.git
cd query
npm install

To run the tests:

npm test

Contributing

Thank you! Please see our contributing guidelines for details.

Donations

If you find this project useful and want to help support further development, please send us some coin. We greatly appreciate any and all contributions. Thank you!

Bitcoin (BTC):

1JUb1yNFH6wjGekRUW6Dfgyg4J4h6wKKdF

Monero (XMR):

46uV2fMZT3EWkBrGUgszJCcbqFqEvqrB4bZBJwsbx7yA8e2WBakXzJSUK8aqT4GoqERzbg4oKT2SiPeCgjzVH6VpSQ5y7KQ

License

@basd/query is MIT licensed.