typeORM 多對多關系不同情況的處理

本文以RBAC權限管理中的用戶和角色舉例碗誉，兩個實體存在多對多的關系奴璃，一個用戶擁有多個角色，一個角色屬于多個用戶鹤耍。typeorm的中文文檔沒有對自定義中間表的說明肉迫，發(fā)現(xiàn)英文有相關說明，但示例代碼貌似有問題稿黄。

一喊衫、中間表有自定義字段的處理

在用戶user和role實體之外，新建一個roleUse的實體（記錄用戶和角色的關聯(lián)關系）杆怕，如此本來是多對多的關系族购，變成了user和role與roleUser二組一對多的關系，這樣雖然會多定義一個實體陵珍，但好處是可以中間表可以擴展定義其它額外的數(shù)據(jù)

用戶實體 user.entity.ts

import { Entity, Column, Index, ManyToMany, JoinColumn, OneToMany, JoinTable, PrimaryGeneratedColumn, CreateDateColumn, UpdateDateColumn } from 'typeorm';
import { Role } from '../../admin/role/role.entity';
import { UserRole } from '../../admin/role/roleUser.entity';
 
@Entity()
export class User {
    @PrimaryGeneratedColumn()
    id: number;
 
    @Column({ length: 100 })
    @Index({ unique: true })
    name: string;
 
    @OneToMany(type => UserRole, userRole => userRole.user)
    userRoles: UserRole[];
}

角色實體role.entity.ts

import { Entity, Column, ManyToMany, OneToMany, JoinTable, JoinColumn } from 'typeorm';
import { BaseEntity } from '../../../common/base/base.entity';
import { UserRole } from './roleUser.entity';

@Entity('role')
export class Role extends BaseEntity {
    @Column({ length: 100 })
    role_name: string;

    @OneToMany(type => UserRole, userRole => userRole.role)
    userRoles: UserRole[];

}

中間表實體 roleUser.entity.ts (主健)

import { Entity, PrimaryGeneratedColumn, JoinColumn, Column, CreateDateColumn, UpdateDateColumn, ManyToOne } from 'typeorm';
import { BaseEntity } from '../../../common/base/base.entity';
import { User } from '../../web/user/user.entity';
import { Role } from './role.entity';
 
@Entity()
export class UserRole {
    @PrimaryGeneratedColumn()
    public id: number;
 
    @CreateDateColumn()
    created_time: Date;
 
    @UpdateDateColumn()
    updated_time: Date;
 
    @ManyToOne(type => User, user => user.userRoles)
    @JoinColumn({name: 'user_id'})
    user: User;
 
    @ManyToOne(type => Role, role => role.userRoles)
    @JoinColumn({name: 'role_id'})
    role: Role;
}

中間表定義roleUser.entity.ts(復合主鍵)

import { Entity, PrimaryGeneratedColumn, JoinColumn, Column, CreateDateColumn, UpdateDateColumn, ManyToOne } from 'typeorm';
import { BaseEntity } from '../../../common/base/base.entity';
import { User } from '../../web/user/user.entity';
import { Role } from './role.entity';
 
@Entity()
export class UserRole {
 
    @CreateDateColumn()
    created_time: Date;
 
    @UpdateDateColumn()
    updated_time: Date;
 
    @ManyToOne(type => User, user => user.userRoles, { primary: true })
    @JoinColumn({name: 'user_id'})
    user: User;
 
    @ManyToOne(type => Role, role => role.userRoles, { primary: true })
    @JoinColumn({name: 'role_id'})
    role: Role;
}

二挺峡、無中間表的多對多實體定義首繁，又分為單向和雙向，單向是僅在一側與關系裝飾器的關系，雙向是與關系兩側的裝飾者的關系赡模。具體官網(wǎng)文檔：https://typeorm.io/#/relations，此處主要講雙向

角色實體

import { Entity, Column, ManyToMany, OneToMany, JoinTable, JoinColumn } from 'typeorm';
import { BaseEntity } from '../../../common/base/base.entity';
import { User } from '../../web/user/user.entity';
 
@Entity('role')
export class Role extends BaseEntity {
    @Column({ length: 100 })
    role_name: string;
 
    @Column({ length: 100 })
    remark: string;
 
    // 無中間實體表的配置
    @ManyToMany(type => User, user => user.roles, { cascade: true })
    users: User[];
 
}

用戶實體

import { Entity, Column, Index, ManyToMany, JoinColumn, OneToMany, JoinTable, PrimaryGeneratedColumn, CreateDateColumn, UpdateDateColumn } from 'typeorm';
import { Role } from '../../admin/role/role.entity';
 
@Entity()
export class User {
    @PrimaryGeneratedColumn()
    id: number;
 
    @Column({ length: 100 })
    @Index({ unique: true })
    name: string;
 
    // 無中間實體表的配置
    @ManyToMany(type => Role, role => role.users)
    @JoinTable({
        name: 'user_role',
        joinColumns: [
            {name: 'user_id'}
        ],
        inverseJoinColumns: [
            {name: 'role_id'}
        ]
    })
    // 下面的定義也能實現(xiàn)
    //   @JoinTable({
    //     name: 'user_role',
    //     joinColumn: { name: 'user_id' },
    //     inverseJoinColumn: { name: 'role_id' },
    //   })
    roles: Role[];
 
}

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