在嵌套的 map 中查询带有时间戳字段的 firestore 文档

Question

My Documents are structured something like this -

fieldOne = "value1"
fieldTwo = "value2"
fieldThree = "value3<Map1 = flights <Map2 = [flight_number] = <travel_date = TimeStamp>>>" 

Here the flight_number (LH760 in image below) key is dynamic and I don't know its value beforehand. Additionally, there could be multiple flight_number's

I want to find all documents where the travel_date is equal to today's date. How can I most efficiently write a query (in Kotlin)?

I tried to filter by created (as a tutorial for myself - not as a solution for my requirement) but zero docs were returned. so I cant wrap my head around how to query within such a complex nested structure -

.whereEqualTo("created", LocalDateTime.now())

Please note: created timestamp can be different from travel_date timestamp.

Answer 1

There is no way in the Firestore API to query in a specific field in an array or on the dynamic keys of a map.

What you can do is modify/augment the data model to allow your use-case. Since you want to query on travel date, add a top-level array field travel_dates where you store all the travel_date values that you also store in the flights field already in a format like "2023-01-17" (for January 17, 2023).

With that field in place, you can query on the new travel_dates field to get all documents for today with something like:

.whereArrayContains("travel_dates", "2023-01-17")