Nestjs, typeorm中的entity中的互相引用问题
20230131-152600
使用nestjs时,用到typeorm,有互相引用关系的entity,老是报错,按照官方文档,最后总会报一个entity metadata not found的错误.
会出错的方式
试了好多次,发现需要这样写,假设有两个entity, 一个是UserEntity, 一个是CarEntity, 互相引用,按以下方法写,会报circular import errors
user.entity.ts
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import {
Column,
Entity,
ManyToMany,
PrimaryGeneratedColumn,
} from 'typeorm';
import { CarEntity } from './car.entity.ts'
@Entity({ name: 'users' })
export class UserEntity() {
@PrimaryGeneratedColumn()
id: number;
@Column()
name: string;
@ManyToMany(() => CarEntity, (car) => car.id)
car: CarEntity
}
|
car.entity.ts
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import {
Column,
Entity,
ManyToMany,
PrimaryGeneratedColumn,
} from 'typeorm';
import { UserEntity } from './user.entity.ts'
@Entity({ name: 'users' })
export class CarEntity() {
@PrimaryGeneratedColumn()
id: number;
@Column()
name: string;
@ManyToMany(() => UserEntity, (user) => user.id)
user: UserEntity
}
|
这种方式就会报找不到循环引用错误的错误: circular import errors,
全部按官方方式写,也会报错
user.entity.ts
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import {
Column,
Entity,
ManyToMany,
PrimaryGeneratedColumn,
} from 'typeorm';
import type { CarEntity } from './car.entity.ts'
@Entity({ name: 'users' })
export class UserEntity() {
@PrimaryGeneratedColumn()
id: number;
@Column()
name: string;
@ManyToMany('CarEntity', 'id')
car: CarEntity
}
|
car.entity.ts
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import {
Column,
Entity,
ManyToMany,
PrimaryGeneratedColumn,
} from 'typeorm';
import type { UserEntity } from './user.entity.ts'
@Entity({ name: 'users' })
export class CarEntity() {
@PrimaryGeneratedColumn()
id: number;
@Column()
name: string;
@ManyToMany('UserEntity', 'id')
user: UserEntity
}
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这样的方式又会报entity metadata not found的错误.
正确的方式
正确的方式是,只需要一个文件按import type方式,另一个文件还是正常import
user.entity.ts
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import {
Column,
Entity,
ManyToMany,
PrimaryGeneratedColumn,
} from 'typeorm';
import { CarEntity } from './car.entity.ts'
@Entity({ name: 'users' })
export class UserEntity() {
@PrimaryGeneratedColumn()
id: number;
@Column()
name: string;
@ManyToMany(() => CarEntity, (car) => car.id)
car: CarEntity
}
|
car.entity.ts
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import {
Column,
Entity,
ManyToMany,
PrimaryGeneratedColumn,
} from 'typeorm';
import type { UserEntity } from './user.entity.ts'
@Entity({ name: 'users' })
export class CarEntity() {
@PrimaryGeneratedColumn()
id: number;
@Column()
name: string;
@ManyToMany('UserEntity', 'id')
user: UserEntity
}
|
这样就OK了.
tag: nestjs, typeorm, entity, metadata not found, circular import errors