通過文檔 ID 獲取單個數據 Reactjs Firebase Web ZF20E3C5E54C3AB3D375D66B6

Question

我想通過選定的 ID 從單個文檔中獲取數據。 I have try with function "child" and "orderByChild" but it seems did not work with web SDK 9. Could you please to help with the new format query of web version 9. Below is my code at table database:

<Link to={`/view/${id}`}>
    {id.data.dateCreate}
</Link>

以及“查看”頁面中的代碼：

const [user, setUser] = useState({});
const { id } = useParams();
useEffect(() => {
    db
      .orderByChild(`reports/${id}`)
      .get()
      .then((snapshot) => {
        if (snapshot.exists()) {
          setUser({ ...snapshot.val() });
        } else {
          setUser({});
        }
      });
  }, [id]);

非常感謝你的幫助！

Answer 1

您可以使用getDoc() function 獲取單個文檔，如下所示：

import { doc, getDoc } from "firebase/firestore";

useEffect(() => {
  const fetchDocById = async () => {
    // Create DocumentReference
    const docRef = doc(db, "reports", id) // db = getFirestore()
    
    // Fetch document
    const docSnap = await getDoc(docRef)
    
    if (snapshot.exists()) {
      setUser({
        ...snapshot.val()
      });
    } else {
      setUser({});
    }
  }
}, [id]);

另請查看： Firestore：在 Web v9 中添加新數據的模式是什么？