Is there any way to get last created document in Firebase Firestore collection? My requirement is when user signed I have to add a document in a collection named 'history'; When the user signed out I want to update that document with a field called 'signout'; So if i get the lastly added document it is very easy to update. Is there any way to do this?
1 Answers
Is there any way to get the last created document in Firebase Firestore collection?
Yes, there is! The simplest way to achieve this is to add a date property to each object in your collection, then simply query it according to this new property descending and call limit(1) function. That's it!
As @eyyo mentioned in his comment, here is a concrete example. Assuming that your database schema looks like this:
Firestore-root
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--- history (collection)
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--- docId (document)
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--- date: June 24, 2020 at 6:46:25 PM UTC+3
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--- //Other properties
This is the required query:
this.historyRef = afs.collection<History>('history', ref => ref.orderBy('date', 'desc').limit(1));
this.history = this.historyRef.snapshotChanges().map(actions => {
return actions.map(a => {
const data = a.payload.doc.data() as Hisotory;
const docId = a.payload.doc.id;
return { docId, ...data };
});
});
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