Sequelize实例化Product模型遇ModelNotInitializedError错误求助

问题场景 #

在服务中执行new Product()实例化模型对象时，抛出如下错误：

ModelNotInitializedError: Model not initialized: Product cannot be instantiated. "Product" needs to be added to a Sequelize instance.

使用仓库模式配置Sequelize，相关代码如下：

Sequelize配置 #

import { join } from "path";
import { Config } from "sequelize";
import { Sequelize } from "sequelize-typescript";

const path = join(__dirname, '..', '/entities/models/*.model.ts')

const sequelize = new Sequelize({
  repositoryMode: true,
  dialect: 'postgres',
  host: 'localhost',
  database: 'postgres',
  port: 5432,
  schema: 'store',
  username: 'postgres',
  password: '123.',
  models: [path],
  modelMatch: (filename, member) => {
    return filename.substring(0, filename.indexOf('.model')).toLowerCase() === member.toLowerCase();
  },
  hooks: {
    afterConnect: async (connection: Sequelize, _config: Config) => {
      try {
        await connection.query('set search_path = store')
      } catch (error) {
        console.log('Error at set search path: ', error)
      }
    }
  }
})

export { sequelize }

Product模型 #

import { Table, Column, Model, BelongsToMany } from 'sequelize-typescript'
import { Category, CategoryProduct } from './index'

@Table({
  timestamps: false,
  modelName: 'tal_product',
  freezeTableName: true,
  underscored: true
})
export class Product extends Model {
  @Column({ primaryKey: true })
  id!: number

  @Column
  name!: string

  @Column
  stock!: number

  @Column({ field: 'is_active' })
  isActive?: boolean

  @BelongsToMany(() => Category, () => CategoryProduct)
  categories?: Category[]
}

Product仓库 #

import { Repository } from 'sequelize-typescript'
import { Category, Product } from '../../../entities/models'
import { sequelize } from '../adminModule'
import { ProductRepository } from './product.repository'

export class ProductRepositoryImp implements ProductRepository {
  productRepository: Repository<Product>
  categoryRepository: Repository<Category>

  constructor() {
    this.productRepository = sequelize.getRepository(Product)
    this.categoryRepository = sequelize.getRepository(Category)
  }
  
  create = async (product: Product): Promise<Product> => {
    return await this.productRepository.create({ ...product })
  }
}

Product服务 #

import { ICreateProduct, IProduct } from '../../../dto/product.dto'
import { Product } from '../../../entities/models'
import { ProductRepository } from '../repositories'
import { ProductServices } from './product.services'

export class ProductServicesImp implements ProductServices {
  private productRepository: ProductRepository

  public constructor(productRepository: ProductRepository) {
    this.productRepository = productRepository
  }
  
  create = async (productDto: ICreateProduct): Promise<IProduct> => {
    const product = new Product()
    product.name = productDto.name
    product.stock = productDto.stock

    return await this.productRepository.create(product)
  }
}

报错原因 #

开启repositoryMode: true后，Sequelize不会自动将导入的原始模型类与实例绑定，直接用new Product()实例化的是未初始化的模型类，不符合Sequelize仓库模式的要求。

解决方案 #

方案一：直接传递DTO数据给仓库（推荐） #

无需手动实例化模型，直接将DTO数据传入仓库的create方法，Sequelize会自动创建关联的模型实例：

// 修改ProductServicesImp的create方法
create = async (productDto: ICreateProduct): Promise<IProduct> => {
  return await this.productRepository.create(productDto)
}

// 同时调整仓库的create方法参数类型（可选，更规范）
create = async (productData: Partial<Product>): Promise<Product> => {
  return await this.productRepository.create(productData)
}

方案二：使用绑定后的模型类实例化 #

如果必须手动实例化，从Sequelize实例中获取已绑定的模型类：

// 在ProductServicesImp中导入sequelize实例
import { sequelize } from '../adminModule'

// 修改create方法
create = async (productDto: ICreateProduct): Promise<IProduct> => {
  // 获取与Sequelize实例绑定后的Product类
  const BoundProduct = sequelize.getModel(Product)
  const product = new BoundProduct()
  product.name = productDto.name
  product.stock = productDto.stock

  return await this.productRepository.create(product)
}

内容的提问来源于stack exchange，提问作者Slayermago