Why Cursor ignores ORM naming conventions

1---
2description: TypeORM entity conventions
3globs: "src/**/*.entity.ts"
4alwaysApply: true
5---
6
7## TypeORM Naming Rules
8- Database uses snake_case column names
9- Entity properties use camelCase
10- SnakeNamingStrategy is configured in data source
11- Do NOT add explicit @Column({ name: 'snake_case' }) — the strategy handles it
12- Use @CreateDateColumn() for created_at (auto-mapped to snake_case)
13- Use @UpdateDateColumn() for updated_at (auto-mapped to snake_case)
14- Use @PrimaryGeneratedColumn('uuid') for IDs
15- Join columns: @JoinColumn() without explicit name (strategy handles it)
16- Table names: @Entity('table_name') with explicit snake_case name
17
18## NestJS Patterns
19- Entities in src/modules/{module}/entities/
20- DTOs in src/modules/{module}/dto/
21- Repositories use @InjectRepository(Entity)

1// Cursor Chat prompt (Cmd+L):
2// @src/config/data-source.ts @.cursor/rules/typeorm.mdc
3// Generate a Product entity for the 'products' table with:
4// - id (UUID primary key)
5// - name (string, not null)
6// - description (text, nullable)
7// - price (decimal 10,2)
8// - stockQuantity (integer, default 0)
9// - isActive (boolean, default true)
10// - categoryId (UUID foreign key to categories)
11// - createdAt, updatedAt timestamps
12//
13// Our SnakeNamingStrategy maps camelCase properties to
14// snake_case columns automatically.

1import { Entity, Column, PrimaryGeneratedColumn, CreateDateColumn, UpdateDateColumn, ManyToOne, JoinColumn } from 'typeorm';
2import { Category } from './category.entity';
3
4@Entity('products')
5export class Product {
6  @PrimaryGeneratedColumn('uuid')
7  id: string;
8
9  @Column({ type: 'varchar', length: 255 })
10  name: string;
11
12  @Column({ type: 'text', nullable: true })
13  description: string | null;
14
15  @Column({ type: 'decimal', precision: 10, scale: 2 })
16  price: number;
17
18  @Column({ type: 'int', default: 0 })
19  stockQuantity: number;
20
21  @Column({ type: 'boolean', default: true })
22  isActive: boolean;
23
24  @ManyToOne(() => Category)
25  @JoinColumn()
26  category: Category;
27
28  @Column({ type: 'uuid' })
29  categoryId: string;
30
31  @CreateDateColumn()
32  createdAt: Date;
33
34  @UpdateDateColumn()
35  updatedAt: Date;
36}

1// Cursor Chat prompt (Cmd+L, Ask mode):
2// @src/ Find all TypeORM entities and check for:
3// 1. Explicit @Column({ name: '...' }) that conflict with
4//    the SnakeNamingStrategy (double transformation)
5// 2. Properties that don't follow camelCase convention
6// 3. @Entity() without explicit table name
7// 4. Missing @CreateDateColumn or @UpdateDateColumn
8// 5. @JoinColumn with explicit name that conflicts with strategy

1// Cursor Chat prompt (Cmd+L):
2// @src/modules/product/entities/product.entity.ts
3// Generate:
4// 1. CreateProductDto with class-validator decorators
5// 2. UpdateProductDto (Partial of Create)
6// 3. A TypeORM migration that creates the products table
7//    with snake_case column names matching our entity
8//    (stock_quantity, is_active, category_id, created_at, updated_at)