NestJS 数据库操作：TypeORM 集成与最佳实践

在上一篇文章中，我们介绍了 NestJS 的基础概念和核心功能。本文将深入探讨如何在 NestJS 中集成 TypeORM，实现数据库操作的最佳实践。

TypeORM 集成配置

1. 安装依赖

首先安装必要的依赖包：

npm install @nestjs/typeorm typeorm pg
# 如果使用 MySQL
# npm install @nestjs/typeorm typeorm mysql2

2. 数据库配置

// src/config/database.config.ts
import { TypeOrmModuleOptions } from '@nestjs/typeorm';

export const databaseConfig: TypeOrmModuleOptions = {
  type: 'postgres',
  host: process.env.DB_HOST || 'localhost',
  port: parseInt(process.env.DB_PORT) || 5432,
  username: process.env.DB_USERNAME || 'postgres',
  password: process.env.DB_PASSWORD || 'postgres',
  database: process.env.DB_DATABASE || 'nestjs_db',
  entities: ['dist/**/*.entity{.ts,.js}'],
  synchronize: process.env.NODE_ENV !== 'production',
  logging: process.env.NODE_ENV !== 'production',
  ssl: process.env.DB_SSL === 'true',
};

// src/app.module.ts
import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';
import { databaseConfig } from './config/database.config';

@Module({
  imports: [
    TypeOrmModule.forRoot(databaseConfig),
    // 其他模块
  ],
})
export class AppModule {}

实体设计与关系映射

1. 基础实体设计

// src/entities/base.entity.ts
import { 
  PrimaryGeneratedColumn, 
  CreateDateColumn, 
  UpdateDateColumn,
  DeleteDateColumn 
} from 'typeorm';

export abstract class BaseEntity {
  @PrimaryGeneratedColumn('uuid')
  id: string;

  @CreateDateColumn()
  createdAt: Date;

  @UpdateDateColumn()
  updatedAt: Date;

  @DeleteDateColumn()
  deletedAt: Date;
}

// src/users/entities/user.entity.ts
import { Entity, Column, OneToMany } from 'typeorm';
import { BaseEntity } from '../entities/base.entity';
import { Post } from './post.entity';

@Entity('users')
export class User extends BaseEntity {
  @Column({ length: 100 })
  name: string;

  @Column({ unique: true })
  email: string;

  @Column({ select: false })
  password: string;

  @OneToMany(() => Post, post => post.author)
  posts: Post[];
}

// src/posts/entities/post.entity.ts
import { Entity, Column, ManyToOne, JoinColumn } from 'typeorm';
import { BaseEntity } from '../entities/base.entity';
import { User } from './user.entity';

@Entity('posts')
export class Post extends BaseEntity {
  @Column()
  title: string;

  @Column('text')
  content: string;

  @Column({ default: false })
  published: boolean;

  @ManyToOne(() => User, user => user.posts)
  @JoinColumn({ name: 'author_id' })
  author: User;
}