Firebase - What is the difference between ref and

2020-05-19 06:55发布

问题:

In Firebase, ref and child are used a lot.

For example - firebase.database().ref('users/<user-id>') will work exactly same as firebase.database().ref('users').child('<user-id>'), so what exactly is the difference between them and when should either of them be used?

回答1:

There is no difference, in any case you have a DatabaseReference instance.

A Firebase reference represents a particular location in your Database and can be used for reading or writing data to that Database location.

The method:

public DatabaseReference getReference (String path)

Gets a DatabaseReference for the provided path.

The method:

public DatabaseReference child (String pathString)

Get a reference to location relative to this one.



回答2:

There is no difference between the two ways you wrote. The only thing is that the first one is a shorthand, where "/" kinda means "child". By the way, the title question you put is not what your question is actually about. "Ref" and "child" are completely different things, because "ref" just makes a reference indicating where the data should go and "child" is specifying the more exact location of that traveling data. I would recommend to change that.