使用 typeorm(OneToMany) 关系查询有限关系？

Question

I use OneToMany relations for adding messages under conversations . Here, I want to query conversation with last messages only.

Here is an example-

const conversation = await this.conversationRepository.find({
    where: [
        { user: { id: reqUser.id }, hide_from_user: false },
        { participant: { id: reqUser.id }, hide_from_participant: false }
    ],
    order: {
        updated_at: "DESC"
    },
    relations: {
        user: true,
        participant: true,
        message: true
    }
});

It returns all messages under particular conversation -

But I need only last message . Then how I have to query it? Please help me, here?

Answer 1

TypeOrm doesn't support that directly, to do that you have to make another query

      import { getRepository } from "typeorm";

      const conversation = await this.conversationRepository.find({
    where: [
        { user: { id: reqUser.id }, hide_from_user: false },
        { participant: { id: reqUser.id }, hide_from_participant: false }
    ],
    order: {
        updated_at: "DESC"
    },
    relations: {
        user: true,
        participant: true,
    }
});

    conversation.messages = await getRepository(Message)
    .createQueryBuilder('message')
    .where('message.conversation = :id' , {conversation.id});
    .limit(1)  
    .orderBy('message.id', 'Desc')
    .getMany()