使用pymong从mongodb删除记录时出现问题

Question

所以我有大约50个文档ID。我的pythonveno列表包含如下所示的文档ID

5ddfc565bd293f3dbf502789
5ddfc558bd293f3dbf50263b
5ddfc558bd293f3dbf50264f
5ddfc558bd293f3dbf50264d
5ddfc565bd293f3dbf502792

但当我试图删除这50个文档ID时，我发现很难。让我解释一下——为了删除所有50个文档，我需要反复运行python脚本。第一次运行脚本时，它会删除10个，下一次运行时，它会删除18个，以此类推。我的for循环非常简单，如下所示

for i in veno:
            vv =  i[0]
            db.Products2.delete_many({'_id': ObjectId(vv)})

Answer 1

我没有任何mongo实例要测试，但是呢

veno = [
'5ddfc565bd293f3dbf502789',
'5ddfc558bd293f3dbf50263b',
'5ddfc558bd293f3dbf50264f',
'5ddfc558bd293f3dbf50264d',
'5ddfc565bd293f3dbf502792',
]

# Or for your case (Whatever you have in **veno**)
veno = [vv[0] for vv in veno]
####

db.Products2.delete_many({'_id': {'$in':[ObjectId(vv) for vv in veno]}})

如果这不起作用，那么也许这个

db.Products2.remove({'_id': {'$in':[ObjectId(vv) for vv in veno]}})

据我所知，delete\u many的第一个参数是filter，所以 它的设计方式是，您不会删除特定的文档 而是满足特定条件的文档。 在上述情况下，最好是通过说->；立即删除所有文档；删除其\u id位于（$in）列表中的所有文档[ObjectId（vv）用于vv in veno]

Answer 2

如果您的列表只是ID，那么您需要：

for i in veno:
    db.Products2.delete_many({'_id': ObjectId(i)})

完整示例：

from pymongo import MongoClient
from bson import ObjectId

db = MongoClient()['testdatabase']

# Test data setup
veno = [str(db.testcollection.insert_one({'a': 1}).inserted_id) for _ in range(50)]

# Quick peek to see we have the data correct
for x in range(3): print(veno[x])

print(f'Document count before delete: {db.testcollection.count_documents({})}')

for i in veno:
    db.testcollection.delete_many({'_id': ObjectId(i)})

print(f'Document count after delete:  {db.testcollection.count_documents({})}')

给出：

5ddffc5ac9a13622dbf3d88e
5ddffc5ac9a13622dbf3d88f
5ddffc5ac9a13622dbf3d890
Document count before delete: 50
Document count after delete:  0