Update_one in pymongo with different fields type

Question

In mongoDB collection I have different field types. Is it possible update doc in this collection with update_one method?

doc = {"upd_time": datetime.datetime.now(), "categories": [1,2,3]}
mng_collection.update_one({"_id": id}, {"$set": doc}, upsert=True)

That code replace existing array in categories field, but I need to add values from doc["categories"] array if not existing in collection doc array.

https://docs.mongodb.com/manual/reference/operator/update/push/ — Alex Blex, Mar 29 '19 at 14:14
In this document: "If the field is not an array, the operation will fail." First field in doc not array — Денис Милованов, Mar 29 '19 at 14:17
push is for arrays. I get it that doc["categories"] is an array, isn't it? — Alex Blex, Mar 29 '19 at 14:52

score 1 · Accepted Answer · answered Mar 29 '19 at 18:12

1

You need to use $push with $each to add elements to the existing array. $set will always replace existing value with new one.

You can try this:

doc = {"upd_time": datetime.datetime.now(), "categories": [1,2,3]}
mng_collection.update_one({"_id": id}, {
    "$set": { "doc.upd_time" : doc.upd_time},
    $push : {categories : {$each : doc.categories}}
}, upsert=True)

Read more about $push documentation, and how to use it with $each here.

answered Mar 29 '19 at 18:12

Ravi Shankar Bharti

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1

Brilliant solution – Денис Милованов Apr 01 '19 at 07:56

Update_one in pymongo with different fields type

1 Answers1