使用@nestjsx/crud创建Category时报Cannot read properties of null错误

[Nest] 14964  - 2023年8月24日 00:15:56   ERROR [ExceptionsHandler] Cannot read properties of null (reading 'options')
TypeError: Cannot read properties of null (reading 'options')
    at CategoryService.createOne (\node_modules\@nestjsx\crud-typeorm\src\typeorm-crud.service.ts:118:35)
    at CategoryController.createOneBase (\node_modules\@nestjsx\crud\src\crud\crud-routes.factory.ts:227:27)
    at \node_modules\@nestjs\core\router\router-execution-context.js:38:29
    at processTicksAndRejections (node:internal/process/task_queues:95:5)

当前行为 #

尝试创建新分类时传入以下JSON参数：

{
  "name": "New Category"
}

触发上述报错，无法创建分类。

输入代码 #

实体（Entity） #

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

import { Product } from './product.entity';

@Entity('category')
export class Category {
  @Column({ name: 'id', type: 'bigint' })
  @PrimaryGeneratedColumn()
  id: number;

  @Column({ name: 'name', nullable: false })
  name: string;

  @CreateDateColumn({ name: 'created_at', type: 'timestamp' })
  CreatedAt: Date;

  @CreateDateColumn({ name: 'updated_at', type: 'timestamp' })
  UpdatedAt: Date;

  @DeleteDateColumn({ name: 'deleted_at', nullable: true })
  DeletedAt?: Date;

  @OneToMany(() => Product, (product) => product.category)
  products: Product[];
}

控制器（Controller） #

import { Controller } from '@nestjs/common';
import { Crud, CrudController } from '@nestjsx/crud';
import { ApiTags } from '@nestjs/swagger';

import { CategoryService } from './category.service';
import { CreateCategoryDto, UpdateCategoryDto } from './dto/category.dto';

import { Category } from '../../database/entity/category.entity';

@ApiTags('category')
@Crud({
  model: {
    type: Category,
  },
  dto: {
    create: CreateCategoryDto,
    update: UpdateCategoryDto,
  },
  query: {
    join: {
      products: {
        eager: true,
      },
    },
  },
  routes: {
    only: [
      'getManyBase',
      'getOneBase',
      'createOneBase',
      'updateOneBase',
      'deleteOneBase',
    ],
  },
})
@Controller('category')
export class CategoryController implements CrudController<Category> {
  constructor(public service: CategoryService) {}
}

服务（Service） #

import { Injectable } from '@nestjs/common';
import { TypeOrmCrudService } from '@nestjsx/crud-typeorm';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';

import { Category } from '../../database/entity/category.entity';

@Injectable()
export class CategoryService extends TypeOrmCrudService<Category> {
  constructor(@InjectRepository(Category) repository: Repository<Category>) {
    super(repository);
  }
}

模块（Module） #

import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';

import { CategoryController } from './category.controller';
import { CategoryService } from './category.service';

import { Category } from '../../database/entity/category.entity';

@Module({
  imports: [TypeOrmModule.forFeature([Category])],
  controllers: [CategoryController],
  providers: [CategoryService],
})
export class CategoryModule {}

数据传输对象（DTO） #

import { ApiProperty } from '@nestjs/swagger';
import { IsNotEmpty, IsOptional, IsString } from 'class-validator';

export class CreateCategoryDto {
  @ApiProperty()
  @IsNotEmpty()
  @IsString()
  name: string;
}

export class UpdateCategoryDto {
  @ApiProperty()
  @IsOptional()
  @IsString()
  name?: string;
}

期望行为 #

成功创建带有指定名称的新分类。

环境信息 #

• 包版本：0.0.1
• Node版本：v18.16.0
• 操作系统：Windows
• 数据库：Postgres
• 依赖版本：
  • "@nestjs/common": "^10.0.0"
  • "@nestjs/core": "^10.0.0"
  • "@nestjs/typeorm": "^10.0.0"
  • "pg": "^8.11.2"
  • "@nestjsx/crud": "^5.0.0-alpha.3"
  • "@nestjsx/crud-typeorm": "^5.0.0-alpha.3"

问题解决 #

报错Cannot read properties of null (reading 'options')根源在于实体类的两个配置错误：

1. ID字段装饰器冲突：同时使用@Column和@PrimaryGeneratedColumn装饰id字段，导致TypeORM无法正确识别主键元数据，进而让@nestjsx/crud获取配置时出现空指针。修改id字段：

@PrimaryGeneratedColumn({ type: 'bigint' })
id: number;

2. 更新时间字段装饰器错误：updated_at使用@CreateDateColumn只会在创建时赋值，更新时不会自动修改，应替换为@UpdateDateColumn：

@CreateDateColumn({ name: 'created_at', type: 'timestamp' })
CreatedAt: Date;

@UpdateDateColumn({ name: 'updated_at', type: 'timestamp' })
UpdatedAt: Date;

修改完成后重启服务，创建分类的请求即可正常执行。

内容的提问来源于stack exchange，提问作者Khanh Nguyen