select is not working for pgsql typeorm nestjs nodejs

Question

I have this entity in nestjs

@Entity("mytable")
export class MyEntity extends CommonEntity {

  @ManyToOne(() => Entity2)
  @JoinColumn({ name: "entity_id", referencedColumnName: "id" })
  @IsInt()
  @IsNotEmpty()
  entityId: number;

  @Column({ name: "user_id", type: "integer", select: false })
  @IsNotEmpty()
  userId: number;

  @ManyToOne(() => UserEntity) // Establish Many-to-One relationship
  @JoinColumn({ name: 'user_id', referencedColumnName: 'id' }) // Specify the join column
  userInfo: UserEntity;
}

i want the response as

[
 {
   entityId, userInfo
 }, {...}
]

entityId and the userInfo based on list of entityIds

for this I am writing this query

async _getUsersForEntities(entityIds: number[]): Promise<MyEntity[]> {
    return this.myRepository.find({
      select: [ "entityId", "userInfo"],
      where: {
        entityId: In(entityIds),
      },
      relations: ['userInfo'], 
    });
  }

but select is not working it is returning all the fields instead of entityId like this

{
    id: 31,
    createdAt: 2023-10-11T14:34:50.446Z,
    status: 'Active',
    userInfo: UserEntity {
      id: 3,
      createdAt: 2023-10-06T13:51:19.232Z,
      status: 'Active',
      imgUrl: null,
      name: 'helo'
    }
  }

how can i fix this. I need entityId along with userInfo

Answer 1

You use @JoinColumn incorrectly at entityId: number;. JoinColumn is meant for fields that are supposed to contain the entity's object to which the join is going to happen, and the name field in @JoinColumn({ name: '...' }) should point to the column where the id of related entity is stored. Essentially it's the same thing you did with userInfo and userId.

So the solution is:

@Entity("mytable")
export class MyEntity extends CommonEntity {
  @Column({ name: "entity_id", type: "integer" })
  @IsInt()
  @IsNotEmpty()
  entityId: number; // <- store the id of the referenced entity in a separate field.
                    // also make sure that you have this `entity_id` column in your database.

  @ManyToOne(() => Entity2)
  @JoinColumn({ name: "entity_id", referencedColumnName: "id" }) // <- point to the field where the id of related entity is stored
  entity: Entity2;

...

// and then this select should do the job
async _getUsersForEntities(entityIds: number[]): Promise<MyEntity[]> {
    return this.myRepository.find({
      select: [ "entityId", "userInfo"],
      where: {
        entityId: In(entityIds),
      },
      relations: ['userInfo'], 
    });
  }