NestJS Drizzle CRUD Generator

Overview

This skill automatically generates complete CRUD (Create, Read, Update, Delete) modules for NestJS applications using Drizzle ORM. It creates all necessary files following the zaccheroni-monorepo patterns.

When to Use

• Creating new entity modules with full CRUD endpoints
• Building database-backed features in NestJS
• Generating type-safe DTOs with Zod validation
• Adding services with Drizzle ORM queries
• Creating unit tests with mocked database

Instructions

Step 1: Identify Feature Requirements

Before generating, gather:

• Entity name (e.g., user, product, order)
• List of fields with types
• Required fields vs optional fields

Step 2: Run the Generator

Execute the generation script:

python scripts/generate_crud.py --feature <name> --fields '<json-array>' --output <path>

Step 3: Field Definition Format

Fields must be defined as JSON array with name, type, and required properties.

Step 4: Integrate Module

After generation, integrate the module into your NestJS application.

Examples

Example 1: Generate a User module

python scripts/generate_crud.py \
  --feature user \
  --fields '[{"name": "name", "type": "string", "required": true}, {"name": "email", "type": "string", "required": true}, {"name": "password", "type": "string", "required": true}]' \
  --output ./libs/server

Example 2: Generate a Product module

python scripts/generate_crud.py \
  --feature product \
  --fields '[{"name": "title", "type": "string", "required": true}, {"name": "price", "type": "number", "required": true}, {"name": "description", "type": "text", "required": false}, {"name": "inStock", "type": "boolean", "required": false, "default": true}]' \
  --output ./libs/server

Quick Start

Step 1: Identify Feature Requirements

Before generating, gather:

• Entity name (e.g., user, product, order)
• List of fields with types
• Required fields vs optional fields

Step 2: Run the Generator

Execute the generation script:

python scripts/generate_crud.py --feature <name> --fields '<json-array>' --output <path>

Step 3: Field Definition Format

Fields must be defined as JSON array:

[
  {"name": "name", "type": "string", "required": true},
  {"name": "email", "type": "string", "required": true},
  {"name": "age", "type": "integer", "required": false},
  {"name": "isActive", "type": "boolean", "required": false, "default": true},
  {"name": "price", "type": "number", "required": true},
  {"name": "description", "type": "text", "required": false},
  {"name": "uuid", "type": "uuid", "required": false}
]

Step 4: Example Commands

Generate a User module:

python scripts/generate_crud.py \
  --feature user \
  --fields '[{"name": "name", "type": "string", "required": true}, {"name": "email", "type": "string", "required": true}, {"name": "password", "type": "string", "required": true}]' \
  --output ./libs/server

Generate a Product module:

python scripts/generate_crud.py \
  --feature product \
  --fields '[{"name": "title", "type": "string", "required": true}, {"name": "price", "type": "number", "required": true}, {"name": "description", "type": "text", "required": false}, {"name": "inStock", "type": "boolean", "required": false, "default": true}]' \
  --output ./libs/server

Generated Structure

The generator creates this directory structure:

libs/server/{feature-name}/
├── src/
│   ├── index.ts
│   └── lib/
│       ├── {feature}-feature.module.ts
│       ├── controllers/
│       │   ├── index.ts
│       │   └── {feature}.controller.ts
│       ├── services/
│       │   ├── index.ts
│       │   ├── {feature}.service.ts
│       │   └── {feature}.service.spec.ts
│       ├── dto/
│       │   ├── index.ts
│       │   └── {feature}.dto.ts
│       └── schema/
│           └── {feature}.table.ts

Supported Field Types

Features

Module

• Uses forRootAsync pattern for lazy configuration
• Exports generated service for other modules
• Imports DatabaseModule for feature tables

Controller

• Full CRUD endpoints: POST, GET, PATCH, DELETE
• Query parameter validation for pagination
• Zod validation pipe integration

Service

• Drizzle ORM query methods
• Soft delete support (via deletedAt column)
• Pagination with limit/offset
• Filtering support
• Type-safe return types

DTOs

• Zod schemas for Create and Update
• Query parameter schemas for filtering
• NestJS DTO integration

Tests

• Jest test suite
• Mocked Drizzle database
• Test cases for all CRUD operations

Manual Integration

After generation, integrate into your app module:

// app.module.ts
import { {{FeatureName}}FeatureModule } from '@your-org/server-{{feature}}';

@Module({
  imports: [
    {{FeatureName}}FeatureModule.forRootAsync({
      useFactory: () => ({
        defaultPageSize: 10,
        maxPageSize: 100,
      }),
    }),
  ],
})
export class AppModule {}

Field Options

Each field supports:

• name: Field name
• type: Data type (string, text, number, integer, boolean, date, uuid, email)
• required: Boolean for mandatory fields
• default: Default value for non-required fields
• maxLength: Maximum length for strings
• minLength: Minimum length for strings

Dependencies

The generated code requires:

• @nestjs/common
• @nestjs/core
• drizzle-orm
• drizzle-zod
• zod
• nestjs-zod

Best Practices

1. Verify generated code: Always review generated files before committing
2. Run tests: Execute unit tests to verify the generated code works
3. Customize as needed: Add business logic to services after generation
4. Database migrations: Manually create migrations for the generated schema
5. Type safety: Use the generated types in your application code

Constraints and Warnings

• Soft delete only: The generated delete method uses soft delete (sets deletedAt). Hard deletes require manual modification
• No authentication: Generated code does not include auth guards - add them separately
• Basic CRUD only: Complex queries or business logic must be implemented manually
• JSON field escaping: When passing fields JSON on command line, use single quotes around the JSON array