I am fetching data from firestore and displaying those data's in a list.But the response which i am getting from firestore contains the document id separately and values separately. At the time of fetching itself i am combining it in a array. I would like to know whether it is the correct way of doing or is there any way we can do it better to combine the document id and values together.
Steps which i have done for combining:
db.getEmployees().then((snapshot) => {
let employee = [];
snapshot.docs.forEach((doc) => {
let user = doc.data();
user.id = doc.id;
employee.push(user);
});
dispatch(employeeUpdateSuccess(employee));
According to the documentation for a DocumentSnapshot, there is no way to get the data and the id in a combined way (i.e. with only one method or via one property). In other words, you will always have to use the two following lines of code:
... = doc.data();
... = doc.id;
Related
Hey guys I try to get data from a document which has a Field value Name and a subcollection named kurzwaffensub but for my project I need to do a collectionGroup query and after that I need the Name value of each document which matches the query from the subcollection.
So let me explain.
First I need to do a collectionGroup query of the documents from the subcollection based on their two parameter kurzHersteller and kurzModell which I marked in green at the picture.
After that I get all Documents of every Subcollection which match the query.
And as you can see the blue document uid is the same uid as in the fieldvalue of every document of the subcollection.
And my goal is to get the red marked fieldvalue of the documents of the main collection after the group query of the subcollection.
But I only want to receive the Names of the documents which match the requirments of the query .
So in this Case i need the Name Felix Sturms because he has a document in his subcollection marked in yellow
which match the Search for kurzHersteller : Andere and kurzKaliber : Andere
I dont know if this is possible or if I need to structure my data in another way. Im a beginner with firebase firestore so perhabs you can help me.
const [test, setTest] = useState([]);
const HEuKA = query(kurzRef,where("kurzHersteller", "==", `${kurzHersteller}` ), where('kurzKaliber' , '==', `${kurzKaliber}`));
const handleClick = async () => {
...blablabla
...
} else if (kurzHersteller && kurzKaliber) {
const modell = await getDocs(HeuKa);
modell.forEach((doc) => {
// doc.data() is never undefined for query doc snapshots
setTest(doc.id, " => ", doc.data());
});
} else { alert('Bitte etwas eingeben')}
}
So thats the first operation after I receive the array of the documents of the subcollection which match the query , i need another operation to get the corresponding documents from the parent collection which contain the information about the Name of the users which have a document in the subcollection which match the values kurzHersteller: Andere and kurzModell: Andere of this example.
Once you get the QuerySnapshot from your collection group query, you can loop over every document and then access the parent document using .parent property present on the DocumentReference of each document. Try running the following code after your first query:
const modell = await getDocs(HeuKa);
const data = [];
for (const doc of modell.docs) {
const parentDoc = await getDoc(doc.ref.parent.parent);
const { Name } = parentDoc.data();
data.push({
...doc.data(),
Name,
});
}
Firestore reads/queries return documents from a single collection, or with collection group queries from all collections with the same name. There is no way in Firestore to include data from the parent document in the same read/query.
The two options you have are:
Read the parent document for any result you get from the subcollection.
Duplicate the necessary information from the parent document in each document in the subcollection.
While #1 is the most common option for people who are new to Firestore (and NoSQL databases in general), as you get more experienced with Firestore you'll often find yourself using #2 more often too.
I think a more robust way, where you don't depend on the structure, is to get the document from 'uid' field you have on each document you get back from the query'. Even better would be to change this field to type "reference", in which case you can just do (assuming you create a field called customerReference as a replacement for uid):
modell.forEach((doc) => {
const customerDoc = await doc.data().customerReference.get();
const name = customerDoc.data().Name;
I'm using vue3 and firestore
Referring to the firestore official document, there was a way to get documents through collection. But this is the way to get all the collection data.
const citiesRef = db.collection('cities');
const snapshot = await citiesRef.get();
snapshot.forEach(doc => {
console.log(doc.id, '=>', doc.data());
});
I want to get a single document through collection.
How to get a single documemt is
const cityRef = db.collection('cities').doc('SF');
const doc = await cityRef.get();
This is a collection followed by a doc().
I can't insert a value in the doc because documemt is an auto-generated ID.
So I don't know what to do.
You have not mentioned the which document you are specifically looking for. In case you don't know the ID of the Firestore Document, you can try running a simple query using .where() like this:
const db = firebase.firestore()
db.collection("cities").where("cityName", "==", 'London').get().then(querySnapshot => {
const matchedDoc = querySnapshot.doc[0]
})
The example above finds the document where the field cityName is equal to London (both case sensitive). QuerySnapshot contains all the documents which matched your condition specified in the where() method. But in case you know there is only one matching document, as in my case I only have one doc with cityName as London, you can directly access the doc data this way: querySnashots.docs[0].data(). querySnapshot.docs is an array. [0] is the first document in it and .data() parses data from the doc. Additionally you can use querySnapshot.size to get count of documents returned from the query.
I want to clean some records of a firestore database. I have a function that receives the records I would like to keep, I check in all the records if id is not in the docsToKeep:firebase documents argument.
I use a foreach for all the records, and I user filter to find the matching id as shown in the working snippet below:
async function checkForNotifClean(docsToKeep:firebase.firestore.QuerySnapshot<firebase.firestore.DocumentData>) {
const db = firebase.firestore();
const notifCollection = db.collection('notifications')
const allData = await notifCollection.get();
allData.docs.forEach(doc => {
const filtered = docsToKeep.docs.filter(entry => entry.id === doc.id);
const needsErase = filtered.length === 0;
if (needsErase) {
const id = doc.id;
notifCollection.doc(id).delete();
}
})
}
Is there a cleaner way to erase all the documents that are not in docsToKeep ? Would be kind of function that get all the objects that are not in both arrays and delete those. I would be happy on improvements on the javascript side to filter out the records to delete, and in the firebase side, improvements regarding the chance of deleting some set of records at once instead of looping through all and deleting each.
To delete (or write to) a document in Firestore you need to know the complete path to that document, including its document ID. If you don't have the IDs of the documents to delete, then your only option is to determine those IDs as you're doing now.
It does lead to the question how docsToKeep is populated though. My guess it that the user already selects some documents from a full list. If that's the case, might you be able to pass the inverted list: docsToDelete?
I am currently working on a mobile app on React and I am having trouble understanding how to save a field from fire store that is an array.
Since I can't post images my database structure is all strings such as username, first name, etc but I have a field called follow list that is an array.
What I want to do is save the usernames from the following list into an array to later search fire store for the username's in the array, this is basically what I want to do so I can render my app's social Feed. I do know that I can probably create another subcollection and write something familiar to what I did to search for users but that was a QuerySnapShot which was overall documents not a specific one and I also know firebase creates an ID for arrays and it increases as the array gets bigger.
I do not want to end up making two more subcollections one for followers and following which I think not ideal right? My current approach is this
export const fetchUserFollowing = async (username) => {
const ref = firebase.firestore().collection('users').doc(username)
let results = []
ref
.get()
.then( doc => {
let data = doc.data()
results = data
})
.catch((err) => {
return 'an error has occurred ', err
})
}
From what I understand is that a DocumentSnapShot .get() function returns an object but what I want is to store follow list into results and then return that but I am not sure how to manipulate the object return to just give me follow List which is an array
https://rnfirebase.io/docs/v5.x.x/firestore/reference/DocumentSnapshot
link to docs
I have this data
I do this query
firebase.database().ref(${path}/buy)
.orderByChild('price').limitToFirst(1)
.once('value')
.then(snapshot => console.log(snapshot.val()))
And I get this result
Then the question is
Is there an easy way to access the price attribute of the one object whose key I don't know?
e.g. snapshot.first().price or snapshot.only().price
Simply put, I want to avoid this
var result = snapshot.val()
var key = Object.keys(result)[0]
var price = result[key].price
When you execute a query against the Firebase Database, there will potentially be multiple results. So the snapshot contains a list of those results. Even if there is only a single result, the snapshot will contain a list of one result.
In your callback you need to handle this list by using snapshot.forEach():
firebase.database().ref(${path}/buy)
.orderByChild('price').limitToFirst(1)
.once('value')
.then(snapshot => {
snapshot.forEach(function(child) {
console.log(child.val());
console.log(child.val().price);
})
})