Python中的MongoDB通知 [英] MongoDB Notification in Python

问题描述

我正在将MongoDB与Python Web应用程序一起使用.我想知道从mongodb发出的通知，无论我在mongodb中进行了什么更改.我正在使用代码:

I am using MongoDB with Python web application. I want to know notification from mongodb whatever i changed in mongodb. i am using the code:

from pymongo import Connection
import time
MONGO_CONNECTION = MongoClient(settings.MONGO_CONNECTION_URL+"/"+settings.MONGO_DATABASE['NAME'], safe=True, j=True)
MONGO_DB = MONGO_CONNECTION[settings.MONGO_DATABASE['NAME']]
collection = MONGO_DB["id_64"]
cursor = collection.find(tailable=True)
while cursor.alive:
    print "inside"
    try:
        doc = cursor.next()
        print "new doc"
        print doc
    except StopIteration:
        time.sleep(1)

我得到了错误:

OperationFailure: database error: Unable to execute query: error processing query: ns=scisphere.orgid_64 limit=0 skip=0
Tree: $and
Sort: {}
Proj: {}
 tailable cursor requested on non capped collection

所以请帮我，我在做什么错.

So help me what is the wrong i am doing.

谢谢.

推荐答案

MongoDB 3.6 支持$changeStream功能可监视集合中的更改.

MongoDB 3.6 supports $changeStream feature to watch changes on a collection.

例如，使用与MongoDB 3.6兼容的PyMongo:

For example using PyMongo compatible with MongoDB 3.6:

   for change in db.collection.watch():
       print(change)

返回的ChangeStream在迭代过程中遇到潜在的可恢复错误时将自动恢复.恢复过程对应用程序是透明的，并确保没有丢失更改流文档.

The ChangeStream returned automatically resumes when it encounters a potentially recoverable error during iteration. The resume process is transparent to the application and ensures no change stream documents are lost.

另一个使用 PyMongo 监视集合中发生的所有插入的示例:

Another example to watch all inserts that are happening on a collection using PyMongo:

    try:
        for insert_change in db.collection.watch(
                [{'$match': {'operationType': 'insert'}}]):
            print(insert_change)

    except pymongo.errors.PyMongoError:

        # We know it's unrecoverable:
        log.error('...')

这篇关于Python中的MongoDB通知的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！