如何从 Firestore 获取文档总数

Question

How to get the total document count from Firestore in Unity c#?

In the below picture is my FireStore DB. I want to know two things.

1. I want to get the total count of documents. How do I get the total count of Documents from the collection "users" in unity C#?

2. How to filter based on the school. And get the name of the person in unity C#?

Answer 1

1. You have at least 2 choices:

   a) Either you retrieve all documents and you count them. This is simple but will cost you as many reads as there are documents (not viable if you have many documents!)

   b) You create a counter in an external document which you increment/decrement on each document creation/deletion. This will cost you some writes but only 1 read to get the count. It is a bit more complex to setup, just make sure the document creation/deletion and the increment/decrement are done as per the same batch operation to avoid inconsistencies in case of errors.

2. Perform a simple query such as collection("users").where("school","==", "XXX").get()