SQL JOIN

ROSETTA STONE

Planned

ROSETTA 12 — Implementation Comparison
Compare many-to-many JOIN handling across languages.

Rosetta Stone SQL JOIN Preview coming soon

ROSETTA 12

Rosetta Stone SQL JOIN

Comparison Contract

Retrieve related technologies through the same junction-table relationship.

Comparison Contract

Retrieve related technologies through the same junction-table relationship.

Objective & Comparison Rule

Build each implementation without changing the shared behavior or visual target.

Rosetta Contract

Objective

Compare many-to-many JOIN handling across languages.

Comparison Rule

Retrieve related technologies through the same junction-table relationship.

Keep equivalent input, behavior, and visible output in every later language version.

Implementation Plan

Keep the comparison surface fixed while language syntax and runtime details change.

Structure

project/
├── data/
│   └── learning.db
├── expected/
│   └── output.json
├── package.json
├── tsconfig.json
├── index.html
├── styles.css
└── src/
    ├── client.ts
    └── server.ts

Initial Implementation

JavaScript / modern ECMAScript
Node.js
SQLite
HTML
CSS

Comparison Languages

JavaScript / modern ECMAScript
TypeScript
Angular
Python
Java
C#
PHP

Source Learning Project

Source Learning Project — TypeScript Lab: Technology JOIN Explorer

src/datastore/queries.ts → getTechnologiesForRecord()

Technologies

JavaScript / modern ECMAScript

TypeScript

Angular

Python

Java

PHP

Build Instructions

Start with the first technology listed under Technologies, then reproduce the same behavior in each following implementation.

Freeze the Contract

Define the exact input, visible behavior, and expected output.

Build Initial Implementation

Implement the reference version with the same standalone visual layer.

Later Comparison

Rebuild without changing the contract.

TypeScript Implementation Reference

This implementation becomes the first concrete Rosetta comparison point.

Reference Code

Use the same input when building later language versions.

const rows = database.prepare(`
  SELECT technologies.name
  FROM technologies
  JOIN record_technologies
    ON technologies.id = record_technologies.technology_id
  WHERE record_technologies.record_id = ?
`).all(recordId);

TypeScript Implementation Configuration

Keep the TypeScript implementation independently buildable; each implementation should keep its own required setup.

package.json

{
  "type": "module",
  "scripts": {
    "build": "tsc",
    "start": "npm run build && node --enable-source-maps dist/server.js"
  },
  "devDependencies": {
    "@types/node": "^26.4.0",
    "typescript": "^7.0.2"
  }
}

tsconfig.json

{
  "compilerOptions": {
    "rootDir": "./src",
    "outDir": "./dist",
    "target": "ES2022",
    "module": "ES2022",
    "lib": ["ES2022", "DOM"],
    "types": ["node"],
    "strict": true,
    "sourceMap": true
  },
  "include": ["src/**/*.ts"]
}

Comparison Dimensions

Record differences that teach language and runtime behavior rather than cosmetic syntax.

Compare

Syntax and data declarations
Typing and validation
Collections and standard-library operations
Modules and file organization
Runtime and build requirements
Database or HTTP APIs when applicable
Visible output and behavioral equivalence