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Firestore billing for writes that have no effect [duplicate]
(1 answer)
Closed 2 years ago.
If I update a document with the same content as the existing one, will it count as a write even if it doesn't change anything to the current document's content?
In other words, does Firestore update the document without checking the values of each key inside the document?
If I update a document with the same content as the existing one, will it count as a write even if it doesn't change anything to the current document's content?
Yes, it does.
In other words, does Firestore update the document without checking the values of each key inside the document?
Yes, it does update, it overwrites the entire document, no matter if is the same or not. Firestore doesn't have a mechanism to check if the document is the same. You should check that out.
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Suppose I wanted to use Google Firebase's Firestore as the backend of a simple website showing a list of (journal) entries, and the ability to view an entry, edit an entry, and delete an entry. Fundamentally, I would want to retrieve the list of entry titles, so I could present in my website a table of contents. Then when the visitor clicks one of the titles, the website would navigate to the entry's content.
Now, my question is, how do I get just the titles without the content, of the entries? As far as I have read, this is not possible. I present this problem here to confirm whether I have missed something, or if it is indeed impossible with Firebase to get some of the data from a collection of records, without having to retrieve all of the data.
how do I get just the titles without the content, of the entries?
As you've already found, the client-side SDKs for Firestore always retrieve full documents. The server-side SDKs and REST API have a projection/selection mechanism to retrieve only a subset of the fields, but that ability does not exist in the client-side SDKs.
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Does updating one field will download the whole document from the database or just update local version?
(1 answer)
Only retrieve changed document field
(1 answer)
Closed 2 years ago.
I have a question about the bandwidth / data usage of a Firestore listener.
I know Firestore will only give the updated documents once it's listening.
Let's say a single document is 0.3 mb. If it gets updated frequently, does the listener has to download the document (0.3 mb) every time or will it only download the "new/updated" data.
This would make a difference for the end-user who is maybe using 4g.
I use Flutter in combination with Firestore.
Thanks!
Every time a document is updated from an active listener, the entire contents of the document are transferred with each update. It does not transfer only the fields that changed.
This question already has answers here:
Firebase Firestore: Is there a way to enforce required fields for all documents in a collection?
(3 answers)
Closed 2 years ago.
I'm creating a Firestore Database that has a "devices" collection then each device has its own document. I already have a device with various fields.
Is there any way I can create a template where the document fields remains the same for all documents and I can just fill in the values upon adding a new device from the Firebase console?
Documents in Firestore only contain exactly what you put in there. There are no "default" or "understood" fields. If you want a document field to contain some value, you will have to write it into each document.
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Can Firestore update multiple documents matching a condition, using one query?
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Updating documents in Cloud Firestore based on a query
(2 answers)
Closed 2 years ago.
i need to update a field in some documents of my users collection, after another document changes, only if those users meet a required criteria. I know i can do querys filtering for the criteria but this would download the documents (i dont need this) i just need to update the field changed in the first document.
is this even posible or should i look for another aproach?
You must know the full path of every document in order to update it. There is equivalent of SQL's "update where" type queries that will both query and update the matching rows. You will need to query first, iterate the results, and update what you need from that set.
This question already has an answer here:
Get last created document in a Firebase Firestore collection
(1 answer)
Closed 2 years ago.
i have many document inside a collection of firebase. But i want to retrieve only the last document which is present at the bottom. You can see the image . i want to retrieve the highlighted document
You can use last in following way to get last document.
Firestore.instance.collection("data").snapshots().last
This will give you only last element.