CODEWITHSUNDEEP
flutterdartgoogle-cloud-firestore
Mario
Mario

Reputation: 27

Sort documents in firestore collection chronologically

Is there a way to sort documents in collection chronologically when they are created? Currently, they are all over the place. For example, in To-Do app, when you add new item to collection, it should display at the bottom, last, not somewhere in the middle.

Upvotes: 1

Views: 49

Answers (2)

Doug Stevenson
Doug Stevenson

Reputation: 317352

You will need to define an order based on some data in the document, and order your queries based on that field.

The typical solution for time-base order to make sure your documents all contain a timestamp field that you can use to sort them. When you call add() (or other methods to update data), you can tell Firestore to use the current time using FieldValue.serverTimestamp():

collection(...).add({
    ...,  // your other fields
    createdOn: FieldValue.serverTimestamp()
})

Then you can use that field to sort when querying with orderBy():

collection(...).orderBy('createdOn')

Upvotes: 2

Will Hlas
Will Hlas

Reputation: 1341

Try using DateTime.now() for the document ID. This should put the collection in chronological order.

For example:

Firestore.instance.collection('Posts').document(DateTime.now().toString()).setData({});

Upvotes: 0

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