MongoDBPyMongo：查询多个条件 - 意外结果

使用MongoDB和PyMongo进行多条件查询时，有时候会遇到一些意外的结果。在本篇文章中，我将为大家介绍这个问题，并提供一些案例代码来解决这个问题。

python
from pymongo import MongoClient
client = MongoClient()
db = client['test']
collection = db['users']
query = {
    'age': {'$gte': 20, '$lte': 30},
    'gender': 'male'
}
result = collection.find(query)

python
from pymongo import MongoClient
client = MongoClient()
db = client['test']
collection = db['users']
query = {
    '$and': [
        {'age': {'$gte': 20, '$lte': 30}},
        {'gender': 'male'}
    ]
}
result = collection.find(query)

python
from pymongo import MongoClient
client = MongoClient()
db = client['test']
collection = db['students']
query = {
    '$and': [
        {'age': {'$gte': 20, '$lte': 25}},
        {'gender': 'female'}
    ]
}
result = collection.find(query)
for student in result:
    print(student)