CODEWITHSUNDEEP
typeorm
emj365
emj365

Reputation: 2314

typeorm - how to add extra field to "many to many" table?

for example:

3 tables

user
user_business_lines_business_line
business_line

those created by typeorm with the declaration in User

@ManyToMany(type => BusinessLine)
@JoinTable()
businessLines: BusinessLine[]

then, how to add columns fields like

@CreateDateColumn({ type: 'timestamp' })
createdAt: Date

@UpdateDateColumn({ type: 'timestamp' })
updatedAt: Date

to user_business_lines_business_line

Upvotes: 18

Views: 25689

Answers (3)

Chinmay
Chinmay

Reputation: 341

It is not possible to add custom column in the auto created many-to-many bridge table. So create another table and give one-to-many and many-to-one relationship between them.

for example:

Three tables

User -> Table 1

BusinessLine -> Table 2

UserBusinessLine -> Bridge Table between User table and BusinessLine table

UserBusinessLine table will contain the foreign key of both parent tables and also we can add custom columns into it.

In User Table

@OneToMany(() => UserBusinessLine, (userBusinessLine) => userBusinessLine.user)
public userBusinessLines: UserBusinessLine[];

In BusinessLine Table

@OneToMany(() => UserBusinessLine, (userBusinessLine) => userBusinessLine.businessLine)
public userBusinessLines: UserBusinessLine[];

In UserBusinessLine Table

@ManyToOne(() => User, (user) => user.userBusinessLines)
public user: User;

@ManyToOne(() => BusinessLine, (businessLine) => businessLine.userBusinessLines)
public businessLine: BusinessLine;

// Custom Colums
@CreateDateColumn({ type: 'timestamp' })
createdAt: Date;

@UpdateDateColumn({ type: 'timestamp' })
updatedAt: Date;

So now the custom table has the foreign keys of User table and BusinessLine table. Also the CreateddateColumn and UpdatedDateColumn

Upvotes: 34

Yugene
Yugene

Reputation: 3232

You can specify custom-join table for ManyToMany relation

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

  @Column()
  name: string

  @ManyToMany(type => BusinessLine, businessLine => businessLine.users)
  @JoinTable({
    name: 'user_business_line',
    joinColumn: {
      name: 'userId',
      referencedColumnName: 'id',
    },
    inverseJoinColumn: {
      name: 'businessLineId',
      referencedColumnName: 'id',
    },
  })
  businessLines: BusinessLine[]
}

@Entity('user_business_line')
export class UserBusinessLine {
  @CreateDateColumn({ type: 'timestamp' })
  createdAt: Date

  @UpdateDateColumn({ type: 'timestamp' })
  updatedAt: Date

  @Column()
  @IsNotEmpty()
  @PrimaryColumn()
  userId: number;

  @Column()
  @IsNotEmpty()
  @PrimaryColumn()
  businessLineId: number;
}

@Entity()
export class BusinessLine {
  @PrimaryGeneratedColumn()
  id: number

  @Column()
  name: string

  @ManyToMany(type => User, user => user.businessLines)
  users: User[]
}

Upvotes: 17

mahnuh
mahnuh

Reputation: 11

If it is just for a createdAt timestamp for example, you could just add an extra column to your user_business_lines_business_line table using migrations like this (I am using Postgres):

ALTER TABLE "user_business_lines_business_line" ADD "createdAt" TIMESTAMP NOT NULL DEFAULT LOCALTIMESTAMP

Upvotes: 0

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