TypeScript Lab: BEGIN and COMMIT Simulator

LAB / EXPLORATION

TypeScript Lab: BEGIN and COMMIT Simulator

Planned

LAB 112 — Database Transactions
Show changes becoming permanent only after a commit.

LAB TypeScript Lab: BEGIN and COMMIT Simulator Preview coming soon

LAB 112

TypeScript Lab: BEGIN and COMMIT Simulator

Concept

Transactions group several database changes into one atomic operation.

Concept

Transactions group several database changes into one atomic operation.

Objective & Explanation

What the project should make visible and why the concept matters.

Learning Target

Objective

Show changes becoming permanent only after a commit.

Explanation

Transactions group several database changes into one atomic operation.

Project Plan

Structure, technologies, data boundary, and source connection.

Structure

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

Technologies

TypeScript
Node.js
SQLite
HTML
CSS

Data Layer

Use SQLite learning rows. Isolate destructive practice from important Sandbox records.

Sandbox Source

src/local-editor/server.ts

Build Instructions

Build only the focused behavior, then use the visual layer to inspect it.

Setup

Create the standalone project folder and listed files.

Implement

Implement the smallest version that demonstrates the concept.

Run & Inspect

Render the returned or changed data in the browser.

Code & Configuration

Starter configuration plus the focused implementation example.

Focused TypeScript

Implement this behavior first, then alter the input.

database.exec("BEGIN;");
try {
  updateFirst();
  updateSecond();
  database.exec("COMMIT;");
} catch (error) {
  database.exec("ROLLBACK;");
  throw error;
}

Starter Configuration

Keep the project independently buildable.

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"]
}

Expected Visual Result

The output is the proof that the concept is working.

Visible Proof

The browser should visibly demonstrate: show changes becoming permanent only after a commit.

Data: SQLite