question is possibly a duplicate but I haven't found anything that provides an appropriate answer to my issue.
I have an ExpressJS server which is used to provide API requests to retrieve data from a MongoDB database. I am using mongoosejs for the MongoDB connection to query/save data.
I am building a route that will allow me to find all data that matches some user input but I am having trouble when doing the query. I have spent a long while looking online for someone with a similar issue but coming up blank.
I will leave example of the code I have at the minute below.
code for route
// -- return matched data (GET)
router.get('/match', async (req, res) => {
const style_data = req.query.style; // grab url param for style scores ** this comes in as a string **
const character_data = req.query.character; // grab url param for character scores ** this comes in as a string **
// run matcher systems
const style_matches = style_match(style_data);
res.send({
response: 200,
data: style_matches
}); // return data
});
code for the query
// ---(Build the finder)
const fetch_matches_using = async function(body, richness, smoke, sweetness) {
return await WhiskyModel.find({
'attributes.body': body,
'attributes.richness': richness,
'attributes.smoke': smoke,
'attributes.sweetness': sweetness
});
}
// ---(Start match function)---
const style_match = async function (scores_as_string) {
// ---(extract data)---
const body = scores_as_string[0];
const richness = scores_as_string[1];
const smoke = scores_as_string[2];
const sweetness = scores_as_string[3];
const matched = [];
// ---(initialise variables)---
let match_count = matched.length;
let first_run; // -> exact matches
let second_run; // -> +- 1
let third_run; // -> +- 2
let fourth_run; // -> +- 3
// ---(begin db find loop)---
first_run = fetch_matches_using(body, richness, smoke, sweetness).then((result) => {return result});
matched.push(first_run);
// ---(return final data)---
return matched
}
example of db object
{
_id: mongoid,
meta-data: {
pagemd:{some data},
name: whiskyname
age: whiskyage,
price: price
},
attributes: {
body: "3",
richness: "3",
smoke: "0",
sweetness: "3",
some other data ...
}
}
When I hit the route in postman the JSON data looks like:
{
response: 200,
data: {}
}
and when I console.log() out matched from within the style match function after I have pushed the it prints [ Promise(pending) ] which I don't understand.
if I console.log() the result from within the .then() I get an empty array.
I have tried using the populate() method after running the find which does technically work, but instead of only returning data that matches it returns every entry in the collection so I think I am doing something wrong there, but I also don't see why I would need to use the .populate() function to access the nested object.
Am I doing something totally wrong here?
I should also mention that the route and the matching functions are in different files just to try and keep things simple.
Thanks for any answers.
just posting an answer as I seem to have fixed this.
Issue was with my .find() function, needed to pass in the items to search by and then also a call back within the function to return error/data. I'll leave the changed code below.
new function
const fetch_matches_using = async function(body, richness, smoke, sweetness) {
const data = await WhiskyModel.find({
'attributes.body': body,
'attributes.richness': richness,
'attributes.smoke': smoke,
'attributes.sweetness': sweetness
}, (error, data) => { // new ¬
if (error) {
return error;
}
if (data) {
console.log(data)
return data
}
});
return data; //new
}
There is still an issue with sending the found results back to the route but this is a different issue I believe. If its connected I'll edit this answer with the fix for that.
I'm currently trying Firestore, and I'm stuck at something very simple: "updating an array (aka a subdocument)".
My DB structure is super simple. For example:
proprietary: "John Doe",
sharedWith:
[
{who: "first#test.com", when:timestamp},
{who: "another#test.com", when:timestamp},
],
I'm trying (without success) to push new records into shareWith array of objects.
I've tried:
// With SET
firebase.firestore()
.collection('proprietary')
.doc(docID)
.set(
{ sharedWith: [{ who: "third#test.com", when: new Date() }] },
{ merge: true }
)
// With UPDATE
firebase.firestore()
.collection('proprietary')
.doc(docID)
.update({ sharedWith: [{ who: "third#test.com", when: new Date() }] })
None works. These queries overwrite my array.
The answer might be simple, but I could'nt find it...
Firestore now has two functions that allow you to update an array without re-writing the entire thing.
Link: https://firebase.google.com/docs/firestore/manage-data/add-data, specifically https://firebase.google.com/docs/firestore/manage-data/add-data#update_elements_in_an_array
Update elements in an array
If your document contains an array field, you can use arrayUnion() and
arrayRemove() to add and remove elements. arrayUnion() adds elements
to an array but only elements not already present. arrayRemove()
removes all instances of each given element.
Edit 08/13/2018: There is now support for native array operations in Cloud Firestore. See Doug's answer below.
There is currently no way to update a single array element (or add/remove a single element) in Cloud Firestore.
This code here:
firebase.firestore()
.collection('proprietary')
.doc(docID)
.set(
{ sharedWith: [{ who: "third#test.com", when: new Date() }] },
{ merge: true }
)
This says to set the document at proprietary/docID such that sharedWith = [{ who: "third#test.com", when: new Date() } but to not affect any existing document properties. It's very similar to the update() call you provided however the set() call with create the document if it does not exist while the update() call will fail.
So you have two options to achieve what you want.
Option 1 - Set the whole array
Call set() with the entire contents of the array, which will require reading the current data from the DB first. If you're concerned about concurrent updates you can do all of this in a transaction.
Option 2 - Use a subcollection
You could make sharedWith a subcollection of the main document. Then
adding a single item would look like this:
firebase.firestore()
.collection('proprietary')
.doc(docID)
.collection('sharedWith')
.add({ who: "third#test.com", when: new Date() })
Of course this comes with new limitations. You would not be able to query
documents based on who they are shared with, nor would you be able to
get the doc and all of the sharedWith data in a single operation.
Here is the latest example from the Firestore documentation:
firebase.firestore.FieldValue.ArrayUnion
var washingtonRef = db.collection("cities").doc("DC");
// Atomically add a new region to the "regions" array field.
washingtonRef.update({
regions: firebase.firestore.FieldValue.arrayUnion("greater_virginia")
});
// Atomically remove a region from the "regions" array field.
washingtonRef.update({
regions: firebase.firestore.FieldValue.arrayRemove("east_coast")
});
You can use a transaction (https://firebase.google.com/docs/firestore/manage-data/transactions) to get the array, push onto it and then update the document:
const booking = { some: "data" };
const userRef = this.db.collection("users").doc(userId);
this.db.runTransaction(transaction => {
// This code may get re-run multiple times if there are conflicts.
return transaction.get(userRef).then(doc => {
if (!doc.data().bookings) {
transaction.set({
bookings: [booking]
});
} else {
const bookings = doc.data().bookings;
bookings.push(booking);
transaction.update(userRef, { bookings: bookings });
}
});
}).then(function () {
console.log("Transaction successfully committed!");
}).catch(function (error) {
console.log("Transaction failed: ", error);
});
Sorry Late to party but Firestore solved it way back in aug 2018 so If you still looking for that here it is all issues solved with regards to arrays.
https://firebase.googleblog.com/2018/08/better-arrays-in-cloud-firestore.htmlOfficial blog post
array-contains, arrayRemove, arrayUnion for checking, removing and updating arrays. Hope it helps.
To build on Sam Stern's answer, there is also a 3rd option which made things easier for me and that is using what Google call a Map, which is essentially a dictionary.
I think a dictionary is far better for the use case you're describing. I usually use arrays for stuff that isn't really updated too much, so they are more or less static. But for stuff that gets written a lot, specifically values that need to be updated for fields that are linked to something else in the database, dictionaries prove to be much easier to maintain and work with.
So for your specific case, the DB structure would look like this:
proprietary: "John Doe"
sharedWith:{
whoEmail1: {when: timestamp},
whoEmail2: {when: timestamp}
}
This will allow you to do the following:
var whoEmail = 'first#test.com';
var sharedObject = {};
sharedObject['sharedWith.' + whoEmail + '.when'] = new Date();
sharedObject['merge'] = true;
firebase.firestore()
.collection('proprietary')
.doc(docID)
.update(sharedObject);
The reason for defining the object as a variable is that using 'sharedWith.' + whoEmail + '.when' directly in the set method will result in an error, at least when using it in a Node.js cloud function.
#Edit (add explanation :) )
say you have an array you want to update your existing firestore document field with. You can use set(yourData, {merge: true} ) passing setOptions(second param in set function) with {merge: true} is must in order to merge the changes instead of overwriting. here is what the official documentation says about it
An options object that configures the behavior of set() calls in DocumentReference, WriteBatch, and Transaction. These calls can be configured to perform granular merges instead of overwriting the target documents in their entirety by providing a SetOptions with merge: true.
you can use this
const yourNewArray = [{who: "first#test.com", when:timestamp}
{who: "another#test.com", when:timestamp}]
collectionRef.doc(docId).set(
{
proprietary: "jhon",
sharedWith: firebase.firestore.FieldValue.arrayUnion(...yourNewArray),
},
{ merge: true },
);
hope this helps :)
addToCart(docId: string, prodId: string): Promise<void> {
return this.baseAngularFirestore.collection('carts').doc(docId).update({
products:
firestore.FieldValue.arrayUnion({
productId: prodId,
qty: 1
}),
});
}
i know this is really old, but to help people newbies with the issue
firebase V9 provides a solution using the arrayUnion and arrayRemove
await updateDoc(documentRef, {
proprietary: arrayUnion( { sharedWith: [{ who: "third#test.com", when: new Date() }] }
});
check this out for more explanation
Other than the answers mentioned above. This will do it.
Using Angular 5 and AngularFire2. or use firebase.firestore() instead of this.afs
// say you have have the following object and
// database structure as you mentioned in your post
data = { who: "third#test.com", when: new Date() };
...othercode
addSharedWith(data) {
const postDocRef = this.afs.collection('posts').doc('docID');
postDocRef.subscribe( post => {
// Grab the existing sharedWith Array
// If post.sharedWith doesn`t exsit initiated with empty array
const foo = { 'sharedWith' : post.sharedWith || []};
// Grab the existing sharedWith Array
foo['sharedWith'].push(data);
// pass updated to fireStore
postsDocRef.update(foo);
// using .set() will overwrite everything
// .update will only update existing values,
// so we initiated sharedWith with empty array
});
}
We can use arrayUnion({}) method to achive this.
Try this:
collectionRef.doc(ID).update({
sharedWith: admin.firestore.FieldValue.arrayUnion({
who: "first#test.com",
when: new Date()
})
});
Documentation can find here: https://firebase.google.com/docs/firestore/manage-data/add-data#update_elements_in_an_array
Consider John Doe a document rather than a collection
Give it a collection of things and thingsSharedWithOthers
Then you can map and query John Doe's shared things in that parallel thingsSharedWithOthers collection.
proprietary: "John Doe"(a document)
things(collection of John's things documents)
thingsSharedWithOthers(collection of John's things being shared with others):
[thingId]:
{who: "first#test.com", when:timestamp}
{who: "another#test.com", when:timestamp}
then set thingsSharedWithOthers
firebase.firestore()
.collection('thingsSharedWithOthers')
.set(
{ [thingId]:{ who: "third#test.com", when: new Date() } },
{ merge: true }
)
If You want to Update an array in a firebase document.
You can do this.
var documentRef = db.collection("Your collection name").doc("Your doc name")
documentRef.update({
yourArrayName: firebase.firestore.FieldValue.arrayUnion("The Value you want to enter")});
Although firebase.firestore.FieldValue.arrayUnion() provides the solution for array update in firestore, at the same time it is required to use {merge:true}. If you do not use {merge:true} it will delete all other fields in the document while updating with the new value. Here is the working code for updating array without loosing data in the reference document with .set() method:
const docRef = firebase.firestore().collection("your_collection_name").doc("your_doc_id");
docRef.set({yourArrayField: firebase.firestore.FieldValue.arrayUnion("value_to_add")}, {merge:true});
If anybody is looking for Java firestore sdk solution to add items in array field:
List<String> list = java.util.Arrays.asList("A", "B");
Object[] fieldsToUpdate = list.toArray();
DocumentReference docRef = getCollection().document("docId");
docRef.update(fieldName, FieldValue.arrayUnion(fieldsToUpdate));
To delete items from array user: FieldValue.arrayRemove()
If the document contains a nested object in the form of an array, .dot notation can be used to reference and update nested fields.
Node.js example:
const users = {
name: 'Tom',
surname: 'Smith',
favorites: {
sport: 'tennis',
color: 'red',
subject: 'math'
}
};
const update = await db.collection('users').doc('Tom').update({
'favorites.sport': 'snowboard'
});
or Android sdk example:
db.collection("users").document("Tom")
.update(
'favorites.sport': 'snowboard'
);
There is a simple hack in firestore:
use path with "." as property name:
propertyname.arraysubname.${id}:
db.collection("collection")
.doc("docId")
.update({arrayOfObj: fieldValue.arrayUnion({...item})})
I'm new to web (and everything asynchronous). I'm trying to complete a two step process in an Angular + Firebase app:
Query a Firestore collection to find the ID of a document that matches a filter (name == 'theName').
Use the ID to then update the document.
I'm coming from the embedded world where I can do something like this (context of the app - I'm trying to keep track of results in a combat robotics competition).
// Update the winning robot's doc with results
// Find the ID of the robot we're looking for (ex. winningRobotName = "Some Name")
this.firestore.collection('robots', ref => ref.where('name', '==', winningRobotName)).snapshotChanges()
.subscribe(data => {
this.bots = data.map(e => {
return {
id: e.payload.doc.id,
name: e.payload.doc.data()['name'],
// other fields
} as Robot;
})
});
let robot = this.bots[0]; <--------- This doesn't work because I reach here before the above call returns.
// Update this robot with new fields
this.firestore.doc('robots/' + robot.id)
.update({
fightCount : robot.fightCount + 1,
winCount : robot.winCount + 1,
// other updates
});
How does one wait for one subscription to return before executing another command? Do you nest the subscriptions? Is there something really basic I just don't know about yet?
Thanks.
I don't think AngularFire helps you here, and would instead do this directly on the regular JavaScript SDK:
ref.where('name', '==', winningRobotName))
.get()
.then((snapshots) => {
snapshots.forEach((doc) =>
doc.ref.update({
id: doc.id,
name: doc.data().name
})
})
})
I'm not exactly sure what name: doc.data().name is supposed to do (as it's an identity operation, delivering the same result as its input), but left it in just in case this matters to you.
So I have an object being returned from Firebase that looks like this:
{key: {name: "test", email: "test", id: "test"}}
How can I get the id out of this object?
If I do returnItem I get that object, so I tried to do returnItem[0] but it's not an array, and I've tried (Object.keys(tempSnap) but that just gives me the key not the object inside it.
This is my current code:
export function sendInvitation(email) {
firebaseRef.database().ref().child('users').orderByChild('email').equalTo(email).on("value", function(snapshot) {
let tempSnap = snapshot.val();
if(tempSnap != null) {
console.log(tempSnap);
}
});
return dispatch => firebaseRef.database().ref(`${userID}/invites`).push("This is a test Message!");
}
This is what it outputs:
Help would be awesome :D
If you already know id and it's a literal, then it's a matter of returnItem.id.
If you already know id and it's a variable, then it's returnItem[id].
If you don't know the keys and want to print all keys and their values, it's:
Object.keys(returnItem).forEach(function(key) {
console.log(key, returnItem[key]);
});
Update
Your new code shows the problem. When you execute a query against the Firebase Database, there will potentially be multiple results. So the snapshot contains a list of those results. Even if there is only a single result, the snapshot will contain a list of one result. Your callback needs to handle the fact that it gets a list by looping over the results with snapshot.forEach():
firebaseRef.database().ref().child('users').orderByChild('email').equalTo(email).on("value", function(snapshot) {
snapshot.forEach(function(child) {
let tempSnap = child.val();
console.log(tempSnap);
});
});
Try this:
firebaseRef.database().ref().child('users').orderByChild('email').equalTo(email).on("value", function(snapshot) {
snapshot.forEach(function(child) {
let keys=child.key;
let ids=child.val().id;
)};
)};
you have:
users
keyid
email:email
name:yourname
id: test
I'm using the following data structure in my application:
var users = {
"tom": { conversations: ["fake-uuid-v4"] },
"bob": { conversations: ["fake-uuid-v4"] }
};
var conversations = {
"fake-uuid-v4": {
user_one: "tom",
user_two: "bob"
}
}
Each user has a collection of keys mapping to the conversation which contains data for the conversation, such as the last messages sent, if a user is typing, etc. The issue is I'm having a really hard time looking up the conversation.
Here's what I've tried, but it doesn't yield any results. (Note: I have this exact data in my firebase application right now, so this is technically a runnable example)
var conversation_id = 'fake-uuid-v4';
firebase.database().ref('/conversations')
.startAt(conversation_id)
.endAt(conversation_id)
.on('child_added', function(snapshot, prevKey) {
if(snapshot.val()) console.log(snapshot);
});
However, it's not pulling anything from the database, if I change the code to
firebase.database().ref('/conversations/'+conversation_id).on('child_added', function(snapshot, prevKey) {
});
Then it prints out each key/value for the conversations added, in this case:
tom
bob
How can I monitor all conversations with a key that's stored in the user's conversations array?
Quick "answer" on why your first snippet won't work:
var conversation_id = 'fake-uuid-v4';
firebase.database().ref('/conversations')
.startAt(conversation_id)
.endAt(conversation_id)
.on('child_added', function(snapshot, prevKey) {
if(snapshot.val()) console.log(snapshot);
});
You're not specifying a order, which means that the data is likely being order by priority. But I'd recommend against this approach anyway, since you're building a query, while you can directly access the child (which will be faster at scale):
var conversation_id = 'fake-uuid-v4';
firebase.database().ref('/conversations')
.child(conversation_id)
.on('child_added', function(snapshot, prevKey) {
if(snapshot.val()) console.log(snapshot);
});