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TypeORM

TypeScript/JavaScript ORM - 装饰器实体、迁移、Active Record 和 Data Mapper

TL;DR

是什么：TypeScript 和 JavaScript（ES7、ES6、ES5）的 ORM。

为什么用：基于装饰器的实体、迁移、多数据库、Active Record 和 Data Mapper。

Quick Start

安装：

npm install typeorm reflect-metadata
npm install pg  # 或 mysql, sqlite3 等

配置（data-source.ts）：

import { DataSource } from 'typeorm';

export const AppDataSource = new DataSource({
  type: 'postgres',
  host: 'localhost',
  port: 5432,
  username: 'user',
  password: 'password',
  database: 'mydb',
  entities: ['src/entity/**/*.ts'],
  synchronize: true, // 生产环境禁用
});

await AppDataSource.initialize();

Cheatsheet

命令描述
npx typeorm migration:create创建迁移
npx typeorm migration:run运行迁移
npx typeorm migration:revert回滚迁移
npx typeorm schema:sync同步 schema

Gotchas

实体定义

import { Entity, PrimaryGeneratedColumn, Column, CreateDateColumn, ManyToOne } from 'typeorm';

@Entity()
export class User {
  @PrimaryGeneratedColumn()
  id: number;

  @Column()
  name: string;

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

  @Column({ nullable: true })
  age: number;

  @Column({ default: true })
  isActive: boolean;

  @CreateDateColumn()
  createdAt: Date;

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

@Entity()
export class Post {
  @PrimaryGeneratedColumn()
  id: number;

  @Column()
  title: string;

  @ManyToOne(() => User, user => user.posts)
  author: User;
}

CRUD 操作

import { AppDataSource } from './data-source';
import { User } from './entity/User';

const userRepository = AppDataSource.getRepository(User);

// 创建
const user = userRepository.create({
  name: 'John',
  email: '[email protected]'
});
await userRepository.save(user);

// 读取
const users = await userRepository.find();
const user = await userRepository.findOneBy({ id: 1 });

// 更新
await userRepository.update(1, { name: 'Johnny' });

// 删除
await userRepository.delete(1);

查询构建器

const users = await userRepository
  .createQueryBuilder('user')
  .where('user.age > :age', { age: 18 })
  .andWhere('user.isActive = :active', { active: true })
  .orderBy('user.name', 'ASC')
  .getMany();

// 带关系
const usersWithPosts = await userRepository
  .createQueryBuilder('user')
  .leftJoinAndSelect('user.posts', 'post')
  .getMany();

// 选择特定字段
const names = await userRepository
  .createQueryBuilder('user')
  .select(['user.id', 'user.name'])
  .getMany();

关系

// 带关系查询
const user = await userRepository.findOne({
  where: { id: 1 },
  relations: ['posts'],
});

// 嵌套关系
const user = await userRepository.findOne({
  where: { id: 1 },
  relations: ['posts', 'posts.comments'],
});

迁移

# 从实体生成迁移
npx typeorm migration:generate -n CreateUsers

# 创建空迁移
npx typeorm migration:create -n AddUserAge

# 运行迁移
npx typeorm migration:run

# 回滚上次迁移
npx typeorm migration:revert
// 迁移文件
import { MigrationInterface, QueryRunner } from 'typeorm';

export class CreateUsers1234567890 implements MigrationInterface {
  public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`
      CREATE TABLE "user" (
        "id" SERIAL PRIMARY KEY,
        "name" VARCHAR NOT NULL
      )
    `);
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.query(`DROP TABLE "user"`);
  }
}

Next Steps