get all documents in collection firestore

1// retrieve a collection
2db.collection('documents')
3  .get()
4  .then(querySnapshot => {
5    const documents = querySnapshot.docs.map(doc => doc.data())
6    // do something with documents
7  })
8
9// retrieve a document
10db.collection('documents')
11  .doc(documentId)
12  .get()
13  .then(snapshot => {
14    const document = snapshot.data()
15    // do something with document
16  })

1    db.collection("users").get().then((querySnapshot) => {
2    querySnapshot.forEach((doc) => {
3        console.log(`${doc.id} => ${doc.data()}`);
4    });
5

1//retrieve one document and save it to userDetails
2const [userDetails, setUserDetails] = useState('')
3db.collection('users').doc(id).get()
4        .then(snapshot => setUserDetails(snapshot.data()))

1async getMarker() {
2    const snapshot = await firebase.firestore().collection('events').get()
3    return snapshot.docs.map(doc => doc.data());
4}
5

1const [hospitalsDetails, setHospitalsDetails] = useState([])
2    useEffect(()=>{
3        //load hospitals into hospitalsList
4        const hospitals = []
5        db.collection('Hospitals').get()
6            .then(snapshot => {
7                snapshot.docs.forEach(hospital => {
8                    let currentID = hospital.id
9                    let appObj = { ...hospital.data(), ['id']: currentID }
10                    hospitals.push(appObj)
11
12                    hospitals.push(hospital.data())
13            })
14            setHospitalsDetails(hospitals)
15        })
16    },[])
17