hi all,
how manage a array of object with pymongo ? I try with find-and_modify , updateone but it’s not right
do you have a exemple to insert a object into my array ou update it
many thanks
I’ve a collection
test :test
state : array
0 :
date : 22-03-2020 xxxx
user : test user
state : pending
1:
date : 22-03-2020 xxxx
user : test user2
state : pending2
how manage a array of object with pymongo ?
Here is an example, using a collection called as arrays with one document.
Initially I inserted a document from the mongo shell, and queried:
> db.arrays.findOne()
{
"_id" : 1,
"state" : [
{
"date" : ISODate("2020-03-25T15:10:22.220Z"),
"user" : "user-1",
"state" : "pending"
},
{
"date" : ISODate("2020-03-26T09:57:17.315Z"),
"user" : "user-2",
"state" : "active"
}
]
}
The array state will be updated to add a new object, then update this new object and finally delete the new object from the array.
The new object is:
{
"date" : "today's date",
"user" : "user-3",
"state" : "none"
}
I used the Python shell to run the following code interactively using PyMongo 3.9 and MongoDB 4.2.
### Connect to MongoDB database and query the arrays collection:
###
>>> import pymongo
>>> from pymongo import MongoClient
>>> client = MongoClient()
>>> db = client.test
>>> collection = db.arrays
>>> import pprint
>>> pprint.pprint(collection.find_one())
{'_id': 1.0,
'state': [{'date': datetime.datetime(2020, 3, 25, 15, 10, 22, 220000),
'state': 'pending',
'user': 'user-1'},
{'date': datetime.datetime(2020, 3, 26, 9, 57, 17, 315000),
'state': 'active',
'user': 'user-2'}]}
###
### Add a new object to the 'state' array, using the '$push' array update operator.
### 'result' is a UpdateResult object.
###
>>> import datetime
>>> result = collection.update_one( { '_id': 1 },
{ '$push': { 'state': { 'date' : datetime.datetime.utcnow(),
'user' : 'user-3', 'state' : 'none'
} } } )
>>> result.matched_count
1
>>> result.modified_count
1
>>> pprint.pprint(collection.find_one())
{'_id': 1.0,
'state': [{'date': datetime.datetime(2020, 3, 25, 15, 10, 22, 220000),
'state': 'pending',
'user': 'user-1'},
{'date': datetime.datetime(2020, 3, 26, 9, 57, 17, 315000),
'state': 'active',
'user': 'user-2'},
{'date': datetime.datetime(2020, 3, 27, 10, 1, 28, 267000),
'state': 'none',
'user': 'user-3'}]}
###
### Update the new object in the 'state' array, using the '$set' update operator.
###
>>> result = collection.update_one( { '_id': 1, 'state.state': 'none' }, { '$set': { 'state.$.state' : 'done' } } )
>>> result.modified_count
1
>>> pprint.pprint(collection.find_one())
{'_id': 1.0,
'state': [{'date': datetime.datetime(2020, 3, 25, 15, 10, 22, 220000),
'state': 'pending',
'user': 'user-1'},
{'date': datetime.datetime(2020, 3, 26, 9, 57, 17, 315000),
'state': 'active',
'user': 'user-2'},
{'date': datetime.datetime(2020, 3, 27, 10, 1, 28, 267000),
'state': 'done',
'user': 'user-3'}]}
###
### Remove the new object from the 'state' array, using the '$pull' array update
operator.
###
>>> result = collection.update_one( { '_id': 1 }, { '$pull': { 'state' : { 'state': 'done' } } } )
>>> result.modified_count
1
>>> pprint.pprint(collection.find_one())
{'_id': 1.0,
'state': [{'date': datetime.datetime(2020, 3, 25, 15, 10, 22, 220000),
'state': 'pending',
'user': 'user-1'},
{'date': datetime.datetime(2020, 3, 26, 9, 57, 17, 315000),
'state': 'active',
'user': 'user-2'}]}
Thanks for the quick feedback and examples. I have successfully implemented the code in my project and it works.