[SOLVED] Flutter search date by date range

Flutter search date by date range

I have saved data in my Firestore database as DateTime.now().millisecondsSinceEpoch;

I want the user to search by date only using datePicker.

Is it possible to do that or do I have to change my data type in the database? If it's possible, how do I do that?

Solution

If you stored the timestamp as milliseconds since the epoch, you can filter on a certain date or date range by using >= and < operators.

A simple example:

var now = DateTime.now();
var start = DateTime(now.year, now.month, now.day);
var end = start.add(Duration(days: 1));

print(now.millisecondsSinceEpoch);
print(start.millisecondsSinceEpoch);
print(end.millisecondsSinceEpoch);

The important variables here:

now is the DateTime when the code runs
start is the DateTime of the start of the day
end is the DateTime at the start of the next day

So if you want to compare a field in Firestore against these values, it'd be something like:

collectionRef
  .where("timestampField", isGreaterThanOrEqualTo: start)
  .where("timestampField", isLessThan: end)
  ...