Drizzle Team•13mo ago

How to get the return Type of a query with relations?

- Imagine having 2 tables: Posts and Users - there is a relation between Posts and users, since 1 user can write several posts. So we define this relation. - now I write a query to retrieve the user and all his/her posts with the syntax:

const user = await db.query.findFirst({
  where: .....
  with: {
    posts: true
  }
});

const user = await db.query.findFirst({
  where: .....
  with: {
    posts: true
  }
});

How can I "extract" / "infer" the type of user beforehand? My goal is to be able to write something like:

class myStore {
  public user: UserWithPosts;
  
  loadUser(id: number){
     this.user = await db.query.findFirst({
        where: .....
        with: {
          posts: true
        }
      }); 
  }
}

class myStore {
  public user: UserWithPosts;
  
  loadUser(id: number){
     this.user = await db.query.findFirst({
        where: .....
        with: {
          posts: true
        }
      }); 
  }
}

2 Replies

medromo•13mo ago

I would create an external helper function that makes the db query and then use the return type for the public user variable

const getUser = async (id: number) => {
  return await db.query.users.findFirst({
    where: .....,
    with: {
      posts: true
    }
  });
};

type UserWithPosts = Awaited<ReturnType<typeof getUser>>;

class myStore {
  public user: UserWithPosts;

  async loadUser(id: number) {
    this.user = await getUser(id);
  };
};

const getUser = async (id: number) => {
  return await db.query.users.findFirst({
    where: .....,
    with: {
      posts: true
    }
  });
};

type UserWithPosts = Awaited<ReturnType<typeof getUser>>;

class myStore {
  public user: UserWithPosts;

  async loadUser(id: number) {
    this.user = await getUser(id);
  };
};

This should do the trick

pMullot•13mo ago

Great idea! I'll try that right away! Thanks a lot!

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How to get the return Type of a query with relations?