In Firebase if I'd like to create a child node with a unique ID it appears I have two options:
Push() :
Use the push() method to append data to a list in multiuser
applications. The push() method generates a unique ID every time a new
child is added to the specified Firebase reference. By using these
auto-generated keys for each new element in the list, several clients
can add children to the same location at the same time without write
conflicts. The unique ID generated by push() is based on a timestamp,
so list items are automatically ordered chronologically.
childByAutoId:
childByAutoId generates a new child location using a unique key and
returns a FIRDatabaseReference to it. This is useful when the children
of a Firebase Database location represent a list of items. The unique
key generated by childByAutoId: is prefixed with a client-generated
timestamp so that the resulting list will be chronologically-sorted.
Whats the difference?
Nevermind, it appears they are the same except they cater to different platforms:
Save Data on IOS
childByAutoId : Add to a list of data. Every time you call childByAutoId, Firebase generates a unique ID, such as user-posts/<user-id>/<unique-post-id>.
Save Data on Web
push() : Add to a list of data. Every time you call push(), Firebase generates a unique ID, such as user-posts/<user-id>/<unique-post-id>.
Related
How to retrieve child nodes data and update values in firebase:
As I want to make an API in which I create parameters to pass values by it.
Like example I have one node in firebase name as users and under it has user amount is 10. I want to get that data of amount from users node and add some value with it like 10+5 will update in database as 15 in my firebase.
I tried to retrieve data from firebase by seeing youtube, but I'm unable to get what I want; I was only able to get the whole users node data at whole.
That sounds like a 2-step process:
Store the value as a number rather than as a string like you now have it.
Then use the atomic increment operation to increment it by 5.
Whenever i will upload the data to the firebase it give random name to the child node. In the image "Upload" this name in given by me but what about inside name i want to change the name of inside the upload root how i can do that
The name inside the Upload is generated using push(), that you are using in your code, that is why you see it.
push() is a method that creates a random id to be able to seperate records in the database and also to be able to easily identify records in the Firebase Database.
push()
Create a reference to an auto-generated child location. The child key is generated client-side and incorporates an estimate of the server's time for sorting purposes. Locations generated on a single client will be sorted in the order that they are created, and will be sorted approximately in order across all clients.
more info here: https://firebase.google.com/docs/reference/android/com/google/firebase/database/DatabaseReference.html#push()
I'm trying to push new data into Firebase but it keeps generating an unique ID and an extra child node for me. How can I stop generating the ID and extra node or is there another way to push data into Firbase? My dataset is given and I just need to dump the dataset into the db. (But I'm slowly updating this given dataset.)
Firease always generates the unique id when using the push method. You can use it as a key or as a parent node. This post describes push in more detail.
https://firebase.googleblog.com/2015/02/the-2120-ways-to-ensure-unique_68.html
You should use set to publish new data to firebase if push doesn't fit your use case. There is also an update method as set will overwrite any data in the given path.
https://firebase.google.com/docs/database/web/save-data
I generally use set for new data, or if I change how I have my data structured, or if I am appending new data in a path, update to make changes to fields for a dataset, and push for sets of data that I want organized in a list by time( i.e. Chat message log ).
When using push() Firebase creates a unique ID or key such as -KKm9iRSax-scGn7m3Lb.
According to the docs:
The push() method generates a unique ID every time a new child is
added to the specified Firebase reference.
And:
The unique ID generated by push() is based on a timestamp, so list
items are automatically ordered chronologically.
Is this ID or key unique to the whole database or only to the reference (like /users)?
Firebase keys are part timestamp and part random characters. So while they should be unique across the whole database there is a small chance that two keys could end up being the same.
Firebase blog: The 2^120 Ways to Ensure Unique Identifiers
I've been creating a consumer who "grants" ids to clients when they perform certain tasks. It occurred to me at some point that it might be entirely superfluous to worry about the path before I do a .push().name() to create new ids.
Does it matter what path I run the .push().name() on to create a unique ID? Does Firebase generate the IDs entirely based on timestamp, without regard to the path the ID will be assigned to?
Currently, push() ids are generated based on timestamps (along with some randomness). The path on which the id is being pushed is not used as part of the id.