TypeScript Lab: Safe Batch Delete

LAB / EXPLORATION

TypeScript Lab: Safe Batch Delete

Planned

LAB 115 — Database Transactions
Delete several selected records as one controlled operation.

LAB TypeScript Lab: Safe Batch Delete Preview coming soon

LAB 115

TypeScript Lab: Safe Batch Delete

Concept

Batch deletion validates IDs and removes related rows within one transaction.

Concept

Batch deletion validates IDs and removes related rows within one transaction.

Objective & Explanation

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

Learning Target

Objective

Delete several selected records as one controlled operation.

Explanation

Batch deletion validates IDs and removes related rows within one transaction.

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 → bulkDeleteRecords()

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.

const marks = ids.map(() => "?").join(", ");

database.prepare(`
  DELETE FROM records
  WHERE id IN (${marks})
`).run(...ids);

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: delete several selected records as one controlled operation.

Data: SQLite