mongodb - pymongo里，dict存储在list内，如何根据key-value值删除或更新该dict？

Question

{
    "title": "hello world",
    "comments": [
                    {"id": 1, "text": "text 1"},
                    {"id": 2, "text": "text 2"},
                    {"id": 3, "text": "text 3"}, 
                    ...
                ],
    "author": "",
    "views": 1000,
}

假设我现在知道某个 comment 的 id=2，想删除 comments 中 id=2 的字典，也就是 {"id": 2, "text": "text 2"} 这条数据，应该怎样写呢？

如果是更新 id=2 的 text 的内容，又该如何写呢？

Answer 1

This can use mongodb’s array locator, details:
http://www.co-ding.com/?p=274

Answer 2

You can delete it from the mongodb command line like this (pymongo basically has the same format, not tested):

db.posts.update({'_id': xxxx}, {'$pull': { 'comments': {'id': 2} }})

Updated, it seems that it is not so straightforward to write, so let’s go through it with for. .
//Or delete it first and then add it? This order may not meet the requirements. .