fql example

query.js

const result = await query(Let({
  // get author document from index by key. assign authorDoc as variable
  authorDoc: Get(Match(Index("unique_authors_by_key"), "haruki-murakami"))
}, Let({
  // select book references from author document. assign bookRefs variable
  bookRefs: Select(["data", "bookRefs"], Var("authorDoc"))
}, Let({}, {
    // start forming the return result here
    id: Select(["ref", "id"], Var("authorDoc")),
    authorName: Select(["data", "name"], Var('authorDoc')),
    // map over the book references and get the document. assign as bookDoc var
    books: Map(Var('bookRefs'), Lambda('bookRef', Let({
      bookDoc: Get(Var('bookRef'))
    }, {
      // format the result
      id: Select(["ref", "id"], Var('bookDoc')),
      title: Select(["data", "title"], Var('bookDoc')),
      // also map over a books category references, to get the category name
      categories: Map(
        Select(["data", "categoryRefs"], Var("bookDoc")),
        Lambda('categoryRef', Let({
          categoryDoc: Get(Var('categoryRef'))
        }, {
          id: Select(["ref", "id"], Var("categoryDoc")),
          name: Select(["data", "name"], Var("categoryDoc"))
        })
      ))
    })))
  })
)))

expect(result).toBe({
  id: "320369985204518980",
  authorName: "Haruki Murakami",
  books: [{
    id: "320370014948425796",
    title: "Kafka on the Shore",
    categories: [{
      id: "319373242721632324",
      name: "Fiction / Literary"
    }]
  }, {
    id: "321288786678906947",
    title: "1Q84",
    categories: [{
      id: "319373242721632324",
      name: "Fiction / Literary"
    }, {
      id: "320369985203470404",
      name: "Fiction / Magical Realism"
    }, {
      id: "321288786618089539",
      name: "Fiction / Dystopian"
    }]
  }
})