Frequently accessed items are cached in memory, so that MongoDB can provide optimal response time.<\/p>\n
db.currentOp();\n\n\/\/ slow queries\ndb.currentOp({\n \"active\": true,\n \"secs_running\": {\"$gt\" : 3},\n \"ns\": \/^test.\/\n});\n\n\/\/ queries not using any index\ndb.adminCommand({ \n \"currentOp\": true,\n \"op\": \"query\", \n \"planSummary\": \"COLLSCAN\"\n});\n\n\/\/ operations with high numYields\ndb.adminCommand({ \n \"currentOp\": true, \n \"ns\": \/^test.\/, \n \"numYields\": {\"$gte\": 100} \n}) \n\ndb.serverStatus().connections\n{\n \"current\" : 269,\n \"available\" : 838591,\n \"totalCreated\" : 417342\n}<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/method\/db.currentOp\/<\/a>
\nhttps:\/\/hackernoon.com\/mongodb-currentop-18fe2f9dbd68<\/a>
\nhttp:\/\/www.mongoing.com\/archives\/6246<\/a><\/p>\nBSON Types<\/h3>\n
ref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/bson-types\/<\/a><\/p>\nCheck If A Document Exists<\/h3>\n
It is significantly faster to use find()<\/code> + limit()<\/code> because findOne()<\/code> will always read + return the document if it exists. find()<\/code> just returns a cursor (or not) and only reads the data if you iterate through the cursor.<\/p>\ndb.getCollection('message').find({_id: ObjectId(\"585836504b287b5022a3ae26\", delivered: false)}, {_id: 1}).limit(1)<\/code><\/pre>\nref:
\nhttps:\/\/stackoverflow.com\/questions\/8389811\/how-to-query-mongodb-to-test-if-an-item-exists<\/a>
\nhttps:\/\/blog.serverdensity.com\/checking-if-a-document-exists-mongodb-slow-findone-vs-find\/<\/a><\/p>\nFind Documents<\/h3>\ndb.getCollection('user').find({username: 'nanababy520'})\n\ndb.getCollection('message').find({_id: ObjectId(\"5a6383b8d93d7a3fadf75af3\")})\n\ndb.getCollection('message').find({_cls: 'Message'}).sort({posted_at: -1})\n\ndb.getCollection('message').find({sender: ObjectId(\"57aace67ac08e72acc3b265f\"), pricing: {$ne: 0}})\n\ndb.getCollection('message').find({\n sender: ObjectId(\"5ac0f56038cfff013a123d85\"),\n created_at: {\n $gte: ISODate('2018-04-21 12:00:00Z'),\n $lte: ISODate('2018-04-21 13:00:00Z')\n }\n})\n.sort({created_at: -1})<\/code><\/pre>\nFind Documents With Regular Expression<\/h3>\ndb.getCollection('user').find({'username': \/vicky\/})<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/query\/regex\/<\/a><\/p>\nFind Documents With An Array Field<\/h3>\n\n$in: [...]<\/code> means "intersection" or "any element in"<\/li>\n$all: [...]<\/code> means "subset" or "contain"<\/li>\n$elemMatch: {...}<\/code> means "any element match"<\/li>\n$not: {$elemMatch: {$nin: [...]}}<\/code> means "subset" or "in"<\/li>\n<\/ul>\nThe last one roughly means not any([False, False, False, False])<\/code> where each False<\/code> is indicating if the item is not in in [...]<\/code>.<\/p>\nref:
\nhttps:\/\/stackoverflow.com\/questions\/12223465\/mongodb-query-subset-of-an-array<\/a><\/p>\ndb.getCollection('message').find({includes: ObjectId(\"5a4bb448af9c462c610d0cc7\")})\n\ndb.getCollection('user').find({gender: 'F', tags: 'promoted'})\ndb.getCollection('user').find({gender: 'F', 'tags.1': {$exists: true}})<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/query\/exists\/#exists-true<\/a><\/p>\nFind Documents With An Array Field Of Embedded Documents<\/h3>\n
Usually, you could use $elemMatch<\/code>.<\/p>\n{'the_array_field': {'$elemMatch': {\n 'a_field_of_each_element': {'$lte': now},\n 'another_field_of_each_element': 123\n}}}<\/code><\/pre>\ndb.getCollection('message').find({\n unlocks: {\n $elemMatch: {\n _cls: 'PointsUnlock',\n user: ObjectId(\"57f662e727a79d07993faec5\")\n }\n }\n})\n\ndb.getCollection('feature.shop.product').find({\n purchases: {\n $elemMatch: {\n _cls: 'Purchase'\n }\n }\n})\n\ndb.getCollection('feature.shop.product').find({\n '_id': 'prod_CWlSTXBEU4mhEu',\n 'purchases': {'$not': {'$elemMatch': {\n '_cls': 'DirectPurchase',\n 'user': ObjectId(\"58b61d9094ab56f912ba10a5\")\n }}},\n})<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/query\/elemMatch\/<\/a><\/p>\nFind Documents With Existence Of Fields Or Values<\/h3>\n\n.find({'field': {'$exists': true}})<\/code>: the field exists<\/li>\n.find({'field': {'$exists': false}})<\/code>: the field does not exist<\/li>\n.find({'field': {'$type': 10}})<\/code>: the field exists with a null<\/code> value<\/li>\n.find({'field': null})<\/code>: the field exists with a null<\/code> value or the field does not exist<\/li>\n.find({'field': {'$ne': null}})<\/code>: the field exists and the value is not null<\/code><\/li>\n.find({'array_field': {'$in': [null, []]}})<\/code><\/li>\n<\/ul>\ndb.test.insert({'num': 1, 'check': 'value'})\ndb.test.insert({'num': 2, 'check': null})\ndb.test.insert({'num': 3})\n\ndb.test.find({});\n\ndb.test.find({'check': {'$exists': true}})\n\/\/ return 1 and 2\n\ndb.test.find({'check': {'$exists': false}})\n\/\/ return 3\n\ndb.test.find({'check': {'$type': 10}});\n\/\/ return 2\n\ndb.test.find({'check': null})\n\/\/ return 2 and 3\n\ndb.test.find({'check': {'$ne': null}});\n\/\/ return 1<\/code><\/pre>\nref:
\nhttps:\/\/stackoverflow.com\/questions\/4057196\/how-do-you-query-this-in-mongo-is-not-null<\/a>
\nhttps:\/\/docs.mongodb.com\/manual\/tutorial\/query-for-null-fields\/<\/a><\/p>\nFind Documents Where An Array Field Does Not Contain A Certain Value<\/h3>\ndb.getCollection('user').update({_id: ObjectId(\"579994ac61ff217f96a585d9\"), tags: {$ne: 'tag_to_add'}}, {$push: {tags: 'tag_to_add'}})\n\ndb.getCollection('user').update({_id: ObjectId(\"579994ac61ff217f96a585d9\"), tags: {$nin: ['tag_to_add']}}, {$push: {tags: 'tag_to_add'}})<\/code><\/pre>\nref:
\nhttps:\/\/stackoverflow.com\/questions\/16221599\/find-documents-with-arrays-not-containing-a-document-with-a-particular-field-val<\/a><\/p>\nFind Documents Where An Array Field Is Not Empty<\/h3>\ndb.getCollection('message').find({unlocks: {$exists: true}})<\/code><\/pre>\nref:
\nhttps:\/\/stackoverflow.com\/questions\/14789684\/find-mongodb-records-where-array-field-is-not-empty<\/a><\/p>\nFind Documents Where An Array Field's Size Is Greater Than 1<\/h3>\ndb.getCollection('user.inbox').find({\n 'messages.0': {'$exists': true}\n})\n\ndb.getCollection('message').find({\n '_cls': 'Message',\n 'unlocks.10': {'$exists': true}\n}).sort({'posted_at': -1})\n\ndb.getCollection('message').find({\n '_cls': 'Message.ChatMessage',\n 'sender': ObjectId(\"582ee32a5b9c861c87dc297e\"),\n 'unlocks': {'$exists': true, '$not': {'$size': 0}}\n})<\/code><\/pre>\nref:
\nhttps:\/\/stackoverflow.com\/questions\/7811163\/query-for-documents-where-array-size-is-greater-than-1\/15224544<\/a><\/p>\nFind Documents With Computed Values Using $expr<\/code><\/h3>\nFor instance, compare 2 fields from a single document in a find()<\/code> query.<\/p>\ndb.getCollection('user').find({\n $expr: {\n $eq: [{$size: '$follows'}, {$size: '$blocks'}]\n }\n})<\/code><\/pre>\nref:
\nhttps:\/\/thecodebarbarian.com\/a-nodejs-perspective-on-mongodb-36-lookup-expr<\/a>
\nhttps:\/\/dzone.com\/articles\/expressive-query-language-in-mongodb-36-2<\/a><\/p>\nProject A Subset Of An Array Field With $filter<\/code><\/h3>\nA sample document:<\/p>\n
{\n \"_id\" : \"message_unlock_pricing\",\n \"seed\" : 42,\n \"distributions\" : {\n \"a\" : 0.5,\n \"b\" : 0.5\n },\n \"whitelist\" : [ \n {\n \"_id\" : ObjectId(\"57dd071dd20fc40c0cbed6b7\"),\n \"variation\" : \"a\"\n }, \n {\n \"_id\" : ObjectId(\"5b1173a1487fbe2b2e9bba04\"),\n \"variation\" : \"b\"\n }, \n {\n \"_id\" : ObjectId(\"5a66d5c2af9c462c617ce552\"),\n \"variation\" : \"b\"\n }\n ]\n}<\/code><\/pre>\nvar now = new Date();\n\ndb.getCollection('feature.ab.experiment').aggregate([\n {'$project': {\n '_id': 1,\n 'seed': 1,\n 'distributions': 1,\n 'whitelist': {\n '$filter': {\n 'input': {'$ifNull': [\"$whitelist\", []]},\n 'as': \"user\",\n 'cond': {'$eq': ['$$user._id', ObjectId(\"5a66d5c2af9c462c617ce552\")]}\n }\n }\n }},\n {'$unwind': {\n 'path': '$whitelist',\n 'preserveNullAndEmptyArrays': true\n }}\n])<\/code><\/pre>\nref:
\nhttps:\/\/stackoverflow.com\/questions\/42607221\/mongodb-aggregation-project-check-if-array-contains<\/a><\/p>\nInsert Documents<\/h3>\ndb.getCollection('feature.launch').insert({\n 'url': '\/\/example.com\/launchs\/5a06b88aaf9c462c6146ce12.jpg',\n 'user': {\n 'id': ObjectId(\"5a06b88aaf9c462c6146ce12\"),\n 'username': 'luke0804',\n 'tags': [\"gender:male\"]\n }\n})\n\ndb.getCollection('feature.launch').insert({\n 'url': '\/\/example.com\/launchs\/57c16f5bb811055b66d8ef46.jpg',\n 'user': {\n 'id': ObjectId(\"57c16f5bb811055b66d8ef46\"),\n 'username': 'riva',\n 'tags': [\"gender:female\"]\n }\n})<\/code><\/pre>\nUpdate Within A For Loop<\/h3>\nvar oldTags = ['famous', 'newstar', 'featured', 'western', 'recommended', 'popular'];\noldTags.forEach(function(tag) {\n db.getCollection('user').updateMany({tags: tag}, {$addToSet: {tags: 'badge:' + tag}});\n});<\/code><\/pre>\nUpdate With Conditions Of Field Values<\/h3>\n
You could update the value of the field to a specified value if the specified value is less than<\/strong> or greater than<\/em> the current value of the field. The $min<\/code> and $max<\/code> operators can compare values of different types.<\/p>\nOnly set posted_at<\/code> to current timestamp if its current value is None or absent.<\/p>\nPost.objects.update_one(\n {\n '_id': bson.ObjectId(post_id),\n 'media.0': {'$exists': True},\n 'title': {'$ne': None},\n 'location': {'$ne': None},\n 'gender': {'$ne': None},\n 'pricing': {'$ne': None},\n },\n {\n '$min': {'posted_at': utils.utcnow()},\n },\n)<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update\/min\/<\/a>
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update\/max\/<\/a><\/p>\nUpdate An Array Field<\/h3>\n
Array update operators:<\/p>\n
\n$<\/code>: Acts as a placeholder to update the first element in an array for documents that matches the query condition.<\/li>\n$[]<\/code>: Acts as a placeholder to update all elements in an array for documents that match the query condition.<\/li>\n$[<identifier>]<\/code>: Acts as a placeholder to update elements in an array that match the arrayFilters<\/code> condition.<\/li>\n$addToSet<\/code>: Adds elements to an array only if they do not already exist in the set.<\/li>\n$push<\/code>: Adds an item to an array.<\/li>\n$pop<\/code>: Removes the first or last item of an array.<\/li>\n$pull<\/code>: Removes all array elements that match a specified query.<\/li>\n$pullAll<\/code>: Removes all matching values from an array.<\/li>\n<\/ul>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update-array\/<\/a>
\nhttp:\/\/docs.mongoengine.org\/guide\/querying.html#atomic-updates<\/a>
\nhttp:\/\/thecodebarbarian.com\/a-nodejs-perspective-on-mongodb-36-array-filters.html<\/a><\/p>\nAdd an element in an array field.<\/p>\n
user_id = '582ee32a5b9c861c87dc297e'\ntag = 'my_tag'\n\nupdated = User.objects \n .filter(id=user_id, tags__ne=tag) \n .update_one(push__tags=tag)\n\nupdated = User.objects \n .filter(id=user_id) \n .update_one(add_to_set__schedules={\n 'tag': tag,\n 'nbf': datetime.datetime(2018, 6, 4, 0, 0),\n 'exp': datetime.datetime(2019, 5, 1, 0, 0),\n })<\/code><\/pre>\nInsert an element into an array at a certain position.<\/p>\n
slot = 2\nPost.objects.filter(id=post_id, media__id__ne=media_id).update_one(__raw__={\n '$push': {\n 'media': {\n '$each': [{'id': bson.ObjectId(media_id)}],\n '$position': slot,\n }\n }\n})<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update\/position\/<\/a>
\nhttp:\/\/docs.mongoengine.org\/guide\/querying.html#querying-lists<\/a><\/p>\nRemove elements in an array field. It is also worth noting that update(pull__abc=xyz)<\/code> always returns 1<\/code>.<\/p>\nuser_id = '582ee32a5b9c861c87dc297e'\ntag = 'my_tag'\n\nupdated = User.objects \n .filter(id=user_id) \n .update_one(pull__tags=tag)\n\nupdated = User.objects \n .filter(id=user_id) \n .update_one(pull__schedules={'tag': tag})<\/code><\/pre>\nRemove multiple embedded documents in an array field.<\/p>\n
import bson\n\nuser_id = '5a66d5c2af9c462c617ce552'\ntags = ['valid_tag_1', 'future_tag']\n\nupdated_result = User._get_collection().update_one(\n {'_id': bson.ObjectId(user_id)},\n {'$pull': {'schedules': {'tag': {'$in': tags}}}},\n)\nprint(updated_result.raw_result)\n# {'n': 1, 'nModified': 1, 'ok': 1.0, 'updatedExisting': True}<\/code><\/pre>\nref:
\nhttps:\/\/stackoverflow.com\/questions\/28102691\/pullall-while-removing-embedded-objects<\/a><\/p>\ndb.getCollection('feature.feeds').updateMany(\n {\n 'aliases': {'$exists': true},\n 'exp': {'$gte': ISODate('2019-03-21T00:00:00.000+08:00')},\n 'items': {'$elemMatch': {'username': 'engine'}},\n },\n {\n '$pull': {\n 'items': {'username': 'engine'},\n }\n }\n);<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update\/pull\/<\/a><\/p>\nYou could also use add_to_set<\/code> to add an item to an array only if it is not in the list, which always returns 1<\/code> if filter()<\/code> matches any document. However, you are able to set full_result=True<\/code> to get detail updated result.<\/p>\nupdate_result = User.objects.filter(id=user_id).update_one(\n add_to_set__tags=tag,\n full_result=True,\n)\n# {'n': 1, 'nModified': 1, 'ok': 1.0, 'updatedExisting': True}<\/code><\/pre>\nref:
\nhttp:\/\/docs.mongoengine.org\/guide\/querying.html#atomic-updates<\/a><\/p>\nUpdate a multi-level nested array field. Yes, arrayFilters<\/code> supports it.<\/p>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update\/positional-filtered\/<\/a>
\nhttps:\/\/stackoverflow.com\/questions\/23577123\/updating-a-nested-array-with-mongodb<\/a><\/p>\nUpdate an embedding document in an array field.<\/p>\n
MessagePackProduct.objects \n .filter(id='prod_CR1u34BIpDbHeo', skus__id='sku_CR23rZOTLhYprP') \n .update(__raw__={\n '$set': {'skus.$': {'id': 'sku_CR23rZOTLhYprP', 'test': 'test'}}\n })<\/code><\/pre>\nref:
\nhttps:\/\/stackoverflow.com\/questions\/9200399\/replacing-embedded-document-in-array-in-mongodb<\/a>
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/method\/db.collection.update\/#db.collection.update<\/a><\/p>\nUpdate specific embedded documents with arrayFilters<\/code> in an array field.<\/p>\nUser data:<\/p>\n
{\n \"_id\" : ObjectId(\"5a66d5c2af9c462c617ce552\"),\n \"username\" : \"gibuloto\",\n \"tags\" : [\n \"beta\",\n \"future_tag\",\n \"expired_tag\"\n ],\n \"schedules\" : [\n {\n \"tag\" : \"valid_tag\",\n \"nbf\" : ISODate(\"2018-05-01T16:00:00.000Z\"),\n \"exp\" : ISODate(\"2020-06-04T16:00:00.000Z\")\n },\n {\n \"tag\" : \"future_tag\",\n \"nbf\" : ISODate(\"2020-01-28T16:00:00.000Z\"),\n \"exp\" : ISODate(\"2020-12-14T16:00:00.000Z\")\n },\n {\n \"tag\" : \"expired_tag\",\n \"nbf\" : ISODate(\"2016-02-12T16:00:00.000Z\"),\n \"exp\" : ISODate(\"2016-04-21T16:00:00.000Z\")\n }\n ],\n}<\/code><\/pre>\nIt is worth noting that <identifier><\/code> in $arrayFilters<\/code> can only contain lowercase alphanumeric characters.<\/p>\nimport bson\n\nuser_id = '5a66d5c2af9c462c617ce552'\ntags = ['from_past_to_future']\n\nupdated_result = User._get_collection().update_one(\n {'_id': bson.ObjectId(user_id)},\n {\n '$addToSet': {'tags': {'$each': tags}},\n '$unset': {'schedules.$[schedule].nbf': True},\n },\n array_filters=[{'schedule.tag': {'$in': [tag for tag in tags]}}],\n)\nprint(updated_result.raw_result)\n# {'n': 1, 'nModified': 1, 'ok': 1.0, 'updatedExisting': True}<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/master\/reference\/operator\/update\/positional-filtered\/<\/a><\/p>\nUpdate An Array Field With arrayFilters<\/code><\/h3>\nYou should use arrayFilters<\/code> as much as possible.<\/p>\nThe syntax of arrayFilters<\/code> would be:<\/p>\ndb.collection.update(\n {<query selector>},\n {<update operator>: {'array.$[<identifier>].field': value}},\n {arrayFilters: [{<identifier>: <condition>}}]}\n)<\/code><\/pre>\nInbox._get_collection().update_many(\n {'messages.id': message_id},\n {'$set': {'messages.$[message].tags': tags}},\n array_filters=[\n {'message.id': message_id},\n ],\n)<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update\/positional-filtered\/<\/a><\/p>\nInsert an element into an array field at a certain position.<\/p>\n
db.getCollection('feature.forums.post').update(\n { _id: ObjectId(\"5b3c6a9c8433b15569cae54e\") },\n {\n $push: {\n media: {\n $each: [{\n \"mimetype\" : \"image\/jpeg\",\n \"url\" : \"https:\/\/example.com\/posts\/5adb795b47d057338abe8910.jpg\",\n \"presets\" : {}\n }],\n $position: 1\n }\n }\n }\n)<\/code><\/pre>\nOr use explicit array index $set<\/code>.<\/p>\nmedia_id = 'xxx'\nmedia_slot = 0\n\nPost.objects \n .filter(id=post_id, **{f'media__{media_slot}__id__ne': media_id}) \n .update_one(__raw__={'$set': {f'media.{media_slot}': {'id': media_id}}})<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update\/position\/<\/a><\/p>\nSet an array field to empty.<\/p>\n
db.getCollection('message').update(\n {'tags': 'pack:joycelai-1'},\n {'$set': {'unlocks': []}},\n {'multi': true}\n)\n\ndb.getCollection('feature.shop.product').update(\n {},\n {'$set': {'purchases': []}},\n {'multi': true}\n)<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/method\/db.collection.update\/<\/a>
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update\/set\/<\/a><\/p>\nRemove elements from an array field.<\/p>\n
var userId = ObjectId(\"57985b784af4124063f090d3\");\n\ndb.getCollection('user').update(\n {'follows.user': userId},\n {'$pull': {'follows': {'user': userId}}},\n {\n 'multi': true,\n }\n);\n\ndb.getCollection('message').update(\n {'_id': {'$in': [\n ObjectId('5aca1ffc4271ab1624787ec4'),\n ObjectId('5aca31ab93ef2936291c3dd4'),\n ObjectId('5aca33d9b5eaef04943c0d0b'),\n ObjectId('5aca34e7a48c543b07fb0a0f'),\n ObjectId('5aca272d93ef296edc1c3dee'),\n ObjectId('5aca342aa48c54306dfb0a21'),\n ObjectId('5aca20756bd01023a8cb02e9')\n ]}},\n {'$pull': {'tags': 'pack:prod_D75YlDMzcCiAw3'}},\n {'multi': true}\n);<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update\/pull\/<\/a><\/p>\nUpdate A Dictionary Field<\/h3>\n
Set a key\/value in a dictionary field.<\/p>\n
tutorial.data = {\n \"price_per_message\": 1200,\n \"inbox\": []\n}\n\nnew_inbox = [\n {\n \"id\": \"5af118c598eacb528e8fb8f9\",\n \"sender\": \"5a13239eaf9c462c611510fc\"\n },\n {\n \"id\": \"5af1117298eacb212a8fb8e9\",\n \"sender\": \"5a99554be9a21d5ff38b8ca5\"\n }\n]\ntutorial.update(set__data__inbox=new_inbox)<\/code><\/pre>\nref:
\nhttps:\/\/stackoverflow.com\/questions\/21158028\/updating-a-dictfield-in-mongoengine<\/a><\/p>\nUpsert: Update Or Create<\/h3>\n
You must use upsert=true<\/code> with uniquely indexed fields. If you don't need the modified document, you should just use update_one(field1=123, field2=456, upsert=True)<\/code>.<\/p>\nAdditionally, remember that modify()<\/code> always reloads the whole object even the original one only loads specific fields with only()<\/code>. Try to avoid using document.DB_QUERY_METHOD()<\/code>, and using User.objects.filter().only().modify()<\/code> or User.objects.filter().update()<\/code> when it is possible.<\/p>\ntag_schedule = TagSchedule.objects \n .filter(user=user_id, tag='vip') \n .modify(\n started_at=started_at,\n ended_at=ended_at,\n upsert=True\n )\n\nuser = User.objects \n .filter(id=user.id, tutorials__buy_diamonds__version=None) \n .modify(set__tutorials__buy_diamonds__version='v1')\n\nupdated = User.objects \n .filter(user=user_id, tag=tag) \n .update_one(\n push__followers=new_follower,\n )<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/method\/db.collection.update\/#update-with-unique-indexes<\/a>
\nhttp:\/\/docs.mongoengine.org\/apireference.html#mongoengine.queryset.QuerySet.modify<\/a>
\nhttp:\/\/docs.mongoengine.org\/apireference.html#mongoengine.queryset.QuerySet.update_one<\/a><\/p>\nRename A Field<\/h3>\n
Simply rename a field with $rename<\/code>.<\/p>\ndb.getCollection('user').updateMany(\n {\n 'phone_no': {'$exists': true},\n 'social.phone-number.uid': {'$exists': false},\n },\n {'$rename': {\n 'phone_no': 'social.phone-number.uid',\n }}\n);<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/operator\/update\/rename\/<\/a><\/p>\nDo some extra data converting and rename the field manually.<\/p>\n
db.getCollection('user').aggregate([\n {'$match': {\n 'twitter.id': {'$exists': true},\n 'social.twitter.uid': {'$exists': false},\n }},\n {'$project': {\n 'twitter_id': '$twitter.id',\n 'twitter_id_str': {'$toString': '$twitter.id'},\n }},\n]).forEach(function (document) {\n printjson({\n 'id': document._id,\n });\n\n db.getCollection('user').updateOne(\n {\n 'twitter.id': document.twitter_id,\n 'social.twitter.uid': {'$exists': false},\n },\n {\n '$unset': {'twitter.id': true},\n '$set': {'social.twitter.uid': document.twitter_id_str}\n }\n )\n})<\/code><\/pre>\nInsert\/Replace Large Amount Of Documents<\/h3>\nconst operations = contracts.map((contract) => {\n \/\/ TODO: should create a new contract if there is any change of the contract?\n \/\/ use MongoDB transaction to change the new one and old one\n return {\n 'replaceOne': {\n 'filter': {'settlement_datetime': currentSettlementMonth.toDate(), 'user': contract.user},\n 'replacement': contract,\n 'upsert': true,\n },\n };\n});\n\ndb.collection('user.contract').bulkWrite(\n operations,\n {ordered: true},\n (bulkError, result) => {\n if (bulkError) {\n return next(bulkError, null);\n }\n\n logger.info('Finished importing all contracts');\n return next(null, result);\n },\n);<\/code><\/pre>\nUpdate Large Numbers Of Documents<\/h3>\n
Use Bulk.find.arrayFilters()<\/code> and Bulk.find.update()<\/code> together.<\/p>\nIn Python:<\/p>\n
import datetime\n\nexpiration_time = datetime.datetime.utcnow() - datetime.timedelta(hours=48)\n\nbulk = Outbox._get_collection().initialize_unordered_bulk_op()\n\nfor outbox in Outbox.objects.only('id').filter(messages__posted_at__lt=expiration_time):\n bulk.find({'_id': outbox.id}).update_one({\n '$pull': {'messages': {\n 'posted_at': {'$lt': expiration_time},\n }},\n })\n\ntry:\n results = bulk.execute()\nexcept pymongo.errors.InvalidOperation as err:\n if str(err) != 'No operations to execute':\n raise err<\/code><\/pre>\nIn JavaScript:<\/p>\n
const operations = docs.map((doc) => {\n logger.debug(doc, 'Revenue');\n\n const operation = {\n 'updateOne': {\n 'filter': {\n '_id': doc._id,\n },\n 'update': {\n '$set': {\n 'tags': doc.contract.tags,\n },\n },\n },\n };\n return operation;\n});\n\ndb.collection('user.revenue').bulkWrite(\n operations,\n {ordered: false},\n (bulkError, bulkResult) => {\n if (bulkError) {\n return next(bulkError, null);\n }\n\n logger.info(bulkResult, 'Saved tags');\n return next(null, true);\n },\n);\n});<\/code><\/pre>\nref:
\nhttps:\/\/docs.mongodb.com\/manual\/reference\/method\/Bulk\/<\/a>