# FIREBASE FIRESTORE
## Get DB Object

// Initialize Cloud Firestore and get a reference to the service
import { getFirestore } from "firebase/firestore";
const db = getFirestore(app);

## Create **Collection** and add a **Document** into it
**Collection create automatically when you add a document to it**

import { collection, addDoc } from "firebase/firestore"; 

try {
  await addDoc(collection("DB OBJECT", "COLLECTION NAME"), {DOCUMENT});
} catch (e) {
  console.error("Error adding document: ", e);
}

**EXAMPLE**

import { collection, addDoc } from "firebase/firestore"; 

try {
  const docRef = await addDoc(collection(db, "users"), {
    first: "Ada",
    last: "Lovelace",
    born: 1815
  });
  console.log("Document written with ID: ", docRef.id);
} catch (e) {
  console.error("Error adding document: ", e);
}

**NOTE : Documents in a collection can contain different sets of information.**

## Read data from Firestore
Retrive all collection documents

getDocs(collection(db , 'collection name'))

**Example**

import { collection, getDocs } from "firebase/firestore"; 

const res = await getDocs(collection(db, "users"));
res.forEach((doc) => {
  console.log(`${doc.id} => ${doc.data()}`);
});

### HOW TO MACK A QUERY IN FIRESTORE

const q = query(collection(db, "cities"), where("capital", "==", true));
// where(field , condition , condition value)

# REACT-FIREBASE-HOOKS
## FIRESTORE HOOKS
1.useCollection(firestore.Query)