readme.md

const firebase = require("...")

FIREBASE FIRESTORE

const db = firebase.firestore()
const DB_COLLECTION_NAME = db.collection("COLLECTION_NAME")

INSERT

const newData = {
    id: Date.now().toString(),
    name: "sam",
    phone: "910000000000"
}

DB_COLLECTION_NAME.set(newData).then((res) => { console.log(res) }).catch((err) => { console.log(err); })

GET ALL DATA

DB_COLLECTION_NAME.get().then((snap) => { snap.forEach((doc) => { console.log(doc); }) }).catch((err) => { console.log(err); })

GET ONE DATA

DB_COLLECTION_NAME.doc(DOC_ID).get().then((doc) => { console.log(doc); }).catch((err) => { console.log(err); })

FILTER

DB_COLLECTION_NAME.where("name", "==", "sam").get().then((snap) => { snap.forEach((doc) => { console.log(doc); }) }).catch((err) => { console.log(err); })

ORDER BY DESC

DB_COLLECTION_NAME.orderBy("date", "desc").get().then((snap) => { snap.forEach((doc) => { console.log(doc); }) }).catch((err) => { console.log(err); })

ORDER BY ASC

DB_COLLECTION_NAME.orderBy("date", "asc").get().then((snap) => { snap.forEach((doc) => { console.log(doc); }) }).catch((err) => { console.log(err); })

UPDATE

const updateData = {
    name: "john",
}

DB_COLLECTION_NAME.doc(DOC_ID).update(updateData).then((res) => { console.log(res) }).catch((err) => { console.log(err); })

DELETE

DB_COLLECTION_NAME.doc(DOC_ID).delete().then((doc) => { console.log(doc); }).catch((err) => { console.log(err); })

#FIREBASE REALTIME

const db = firebase.database()

const DB_COLLECTION_NAME = db.ref("COLLECTION_NAME")

INSERT

const newData = {
    id: Date.now().toString(),
    name: "sam",
    phone: "910000000000"
}

DB_COLLECTION_NAME.set(newData).then((res) => { console.log(res) }).catch((err) => { console.log(err); })

DB_COLLECTION_NAME.push(newData).then((res) => { console.log(res) }).catch((err) => { console.log(err); })

GET ALL DATA

DB_COLLECTION_NAME.on('value', (snapshot) => { console.log(snapshot.val()); }).catch((err) => { console.log(err); })

DB_COLLECTION_NAME.once('value', (snapshot) => { console.log(snapshot.val()); }).catch((err) => { console.log(err); })

GET ONE DATA

DB_COLLECTION_NAME.child(DOC_ID).get().then((snapshot) => { console.log(snapshot.val()); }).catch((err) => { console.log(err); })

FILTER

DB_COLLECTION_NAME.where("name", "==", "sam").get().then((snap) => { snap.forEach((doc) => { console.log(doc); }) }).catch((err) => { console.log(err); })

UPDATE

const updateData = {
    name: "john",
}

DB_COLLECTION_NAME.child(DOC_ID).update(updateData).then((snap) => { console.log(snap) }).catch((err) => { console.log(err); })

DELETE

DB_COLLECTION_NAME.doc(DOC_ID).delete().then((snap) => { console.log(snap); }).catch((err) => { console.log(err); })

FIREBASE STORAGE

async function uploadImage(file) {
    const image = new Promise((resolve, reject) => {
        var path = `file/${userid}/`
        var fileName = `${Date.now().toString()}.${extention}`
        var storageRef = firebase.storage().ref(path + fileName);
        storageRef.put(file).then(function (snapshot) {
            console.log('Uploaded a blob or file!');
            storageRef.getDownloadURL().then(function (url) {
                resolve(url)
            })
        });
    });

    const imageURL=await image
    return imageURL
}

Firebase
Official Documentation