python - Mongoengine 怎样查询 ListField 里 不包含某个 value 所有结果

Question

class Post(Document)
    tags = ListField(StringField())

tags 可以是 ["php", "python", "perl"]，还可以是 ["ruby", "java"] 之类的

假设，我要列出 tags 里所有不包含 php 的 post，应该怎么写查询？

Answer 1

In fact, just use $ne.

from pymongo import MongoClient

client = MongoClient("mongodb://127.0.0.1")
db = client["your-db"]
collection = db["your-collection"]
iter = collection.find({
    "tags": {
        "$ne": "php",
    },
})

Answer 2

Post.objects(tags__ne='php')

Answer 3

用 $nin

Consider the following query:

db.inventory.find( { qty: { $nin: [ 5, 15 ] } } )

If the field holds an array, then the $nin operator selects the documents whose field holds an array with no element equal to a value in the specified array (e.g. , , etc.).