I have a collections called 'users' and I want to add new field called 'status: boolean' to already exists every documents using cloud functions and firestore database instantly.
There is no bulk update operation, so you will have to:
Query the collection for all documents
Iterate each one
Update the document with the new field
Related
I am making an application in which i have to make invoice of cars and the pattern i am using to store the invoice is shown in image below
containerInvoice: {
invoiceNo:123,
total:$9000,
container:{
containerNo:911,
containerTotal:$201999
units:{
id:199,
chasis:a829nn,
}
}
}
if i directly delete containerInvoice's document then it is delete successfully but it leave it's sub-collection and sub-sub-collection undelete.
the way i fount to delete whole collection including its child collection is to access these documents by document's id and delete it, but it is a lengthy process.
Is there any way to delete a parent collection and all the child collection deleted automatically
As #danh pointed out, according to the documentation, when you delete a document, Cloud Firestore does not automatically delete the documents within its subcollections.
If you want to delete a document and all the documents within its subcollections, you must do so manually [1].
To delete an entire collection or subcollection in Cloud Firestore, retrieve all the documents within the collection or subcollection and delete them [2].
[1] - https://firebase.google.com/docs/firestore/manage-data/delete-data#delete_documents
[2] - https://firebase.google.com/docs/firestore/manage-data/delete-data#collections
What would be the correct command to find a document in a MongoDB database, update it and then insert the updated document as a new document with a new _id?
The original document should remain completely unchanged.
Are you using mongoose, MongoDB shell or Compass?
If you want to find a document and update it, why do you need a new id?
If you want to update an existing document, the id will remain the same, or you can a find and copy an existing document to a new one and update the new doc.
I am using python and mongoengine for this project.
And i am creating a restAPI. Since save() query in mongo inserts new or updates existing document.
SearchRating(stars=4, comment='').save() // returns "None" on success
This particular piece of code in mongoengine only creates new document. However the idea is that only once user is suppose to create this document, later they should only update it. But for updation i need to know what _id i just added in mongodb in search_rating collection.
So how shall i know the _id of document that i just added?
use <databasename> will set a variable db to be the database
specified by <databasename>, so the database can be referred to
the variable db.
I wonder if a collection or document can also be
referred to by a variable, and if yes, how?
Every object in a MongoDB server has an identifier _id. If I am correct, a database, a collection and a document are objects.
How are the identifier of an object used in practice?
Both a database and a collection have a name. So we can refer to a
collection via its name e.g. mydb.mycollection.
Does a document also have a name?
Thanks.
A collection consists of several documents so a document as such do not have any name. _id distinguishes the documents. To fetch any particular document, you can filter it on the basis of _id or the data stored in it.
Referencing the db and then the collection in selected db will give you the required document.
How to insert new document in a MongoDB collection if there's no other document with specified unique field exists, or update the existing one otherwise?
Is there anything more reasonable than just using findOne and save methods with some conditions?