Firestore 多对多关系 - 如何更新数据？

Question

Like a note app, you can set tags to a note. Also, you can search notes with tag. Here is the firestore structure:

notes(collection)
    note_1(doc)
        content: 'some words...'
        tags: ['apple', 'banana']

tags(collection)
    tag_1(doc)
        name: 'apple'
    tag_2(doc)
        name: 'banana'

If I change tag_1.name to 'new_apple', how shold I update note_1.tags?

Answer 1

You're going to have to:

1. Query for all notes documents where the tags array contains "apple"
2. Iterate the documents in the result set. For each document:
   1. Update update the tags array in memory to remove "apple" and add "new_apple"
   2. Write the new tags array back to the document