How can i update multiple documents in firestore by using a single transaction i searched but i didn't get any answers. Is it possible to update multiple documents in a single transaction? I know it can be done by batch writes.
I figured it out we can use multiple ref inside a transaction:
var userSuhail = db.collection(users).doc(suhail);
var userSam = db.collection(users).doc(sam);
var userJohn = db.collection(users).doc(john);
var userAlfred = db.collection(users).doc(Alfred);
var userAlfredDetails = db.collection('userdetails').doc('Alfred');
db.runTransaction(function (transaction) {
return transaction.get(userJohn).then(function (sDoc) {
var age = sDoc.data().age + 1;
transaction.set(userAlfred, {
name: 'Alfred',
age,
details: userAlfredDetails,
});
transaction.set(userAlfredDetails, {
address: 'Alfred Villa',
});
transaction.update( userJohn , { age, }, );
transaction.update( userSuhail , { age, }, );
transaction.update( userSam , { age, }, );
return age;
});
}).then(function (age) {
console.log(Age changed to , age);
}).catch(function (err) {
console.error(err);
});
By the above code the transaction updates age of all users.
