Mongodb remove duplicate documents from a collection. Feb 3, 2024 · Basic Collection Cloning.

Mongodb remove duplicate documents from a collection. 2 (and 4. 6 or older: Learn how to remove duplicate records in MongoDB using a simple query. Aug 1, 2012 · How can I duplicate a document in MongoDB, changing the _id of the new one? Imaging that you have the original document: > var orig = db. Once you find the duplicates, you can easily remove those from Mongo collection. forEach(function(doc) { db. deleteMany({}) -> to select the collection and deletes all the data. Let's say, you have 100k documents to delete from a collection. insertOne({FirstName:David}); { acknowledged : tru Nov 3, 2021 · Because of an accident while coding that our documents are having some duplicated keys. 84358 above) and if there are several documents in collection that have that sequence in the Link field. Let us create a collection with documents −> db. renameCollection When specifying collation, the locale field is mandatory; all other collation fields are optional. 5. If I manually try to delete the key, it is taking hours. 4. What’s the easier/most efficient way to accomplish this? I see there’s no longer dropdups. delete_many method. Feb 2, 2024 · Remove Duplicate Documents From the Collection in MongoDB. Sometimes you want to remove all the duplicate documents from a collection but you don’t know how to find them. The index creation is quite slow, takes about 2 hours despite using most of the RAM and it is erroring out at 99% saying there is a dupe key. Mar 2, 2018 · If I want to delete duplicate documents in a MongoDB collection using Scala, how would one go about doing it? Pretty sure it's simple but I always keep finding ways to do it in Mongo Shell. I have many documents as such. I did use aggregation to delete those duplicates, but it is slow and is not ideal when we deploy it to prod. Aug 1, 2012 · Since there is no insert date, it will be hard to tell looking at document which one is latest (bad schema design) Wanted. To delete a single document sorted by a specified order, use the findAndModify() method. Mongo churns away at it for a while before it decides that too many dups on index build with dropDups=true. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand Specify the justOne option to limit the operation to removing a single document. This step-by-step guide will show you how to identify and remove duplicate records from your MongoDB database, so you can keep your data clean and organized. For an example of a document { key1: {} key1: null } Is there an easy way to find keys like that and remove the first one or the one which having value that is null across documents in a collection? Thanks Mar 10, 2017 · Indexes are special data structures that store a small portion of the collection’s data set in an easy to traverse form. You can edit any of these fields and values before you insert the new document. theCollectionWithoutDuplicates. First of all, we need to sort the documents of a collection based on specific criteria, and after that, we need to define a function for each document using the method forEach(). 0. Time Series Collections Feb 16, 2023 · Use the following MongoDB operations to identify duplicate documents in your collections, and remove them safely. I tried running ensureIndex({id:1}, {unique:true, dropDups:true}) on the collection. demo438. When removing multiple documents, the remove operation may interleave with other read and/or write operations to the collection. Feb 29, 2012 · Find all duplicate documents in a MongoDB collection by a key field. May 15, 2020 · How to remove duplicates from MongoDB Collection - For this, set “unique:true” i. Solution: Ensure that the upsert query uniquely identifies the document to prevent unintended document creation that violates unique constraints. Determines which document the operation updates if the query selects multiple documents. <collection>. It is often advised to delete documents in smaller chunks. find({ a: 1 }, { _id: 0 }). remove() to remove the existing documents and reuse the Starting in MongoDB 4. Method 1: Using Distinct and Remove This method involves identifying unique documents based on a key(s) and then deleting duplicates. ensureIndex({name: 1, nodes: 1}, {unique: true, dropDups: true}) Feb 3, 2024 · This tutorial covers various methods to remove duplicate documents in MongoDB, ranging from simple queries to more complex aggregation processes. Dec 15, 2021 · Find Duplicate Documents In MongoDB Collection. var query = {name: 'John'}; db. The following example deletes all documents from the inventory collection: Mar 8, 2014 · db. I Run a loop through all documents of source_collection, data2 with same indexes or want to delete or add some index mongodb duplicate a collection within the Jul 2, 2022 · Context: I have a MongoDB database with some duplicated documents. After you select a collection, Compass shows you that collection's Documents tab. show dbs -> to list all the database use test-database -> to select the database db. yourCollectionName. Without indexes, MongoDB must perform a collection scan, i. findOne({_id: 'hi'}) And now I want another document in the collection with _id 'bye'. Jun 3, 2015 · Use the cursor result from the aggregation to loop through the documents with the cursor's forEach() method and then remove each document from the collection using the _id as the query in the remove() method. In the example above it would remove one document, either {name:"duplicate", value:true, id:2910921} or {name:"duplicate", value:true, id:32838293}, it does't matter to me which one. Oct 18, 2021 · In this post, I describe how to find duplicated documents in a MongoDB collection using a query or a GUI. The query I have is as follows: db. I am unable to figure out a way to do that. insert(doc); }); Aug 1, 2022 · Database Management System: Most database management systems offer a built-in mechanism for identifying and removing duplicates. If you are certain that the source_references. Remove Duplicates on mongodb. Mar 18, 2021 · I have tried a lot of scripts for remove the duplicate rows in my mongodb collection but doesn't works for me, can i find someone here for help me. e. This might seem a bit confusing because in SQL you only need to use a simple “Group By”, which will display the data fields grouped by certain column like in the following example: To see collection details, either: Click a Collection Name in the main Collections screen, or. 1. 0 you will need to use Aggregation . For example, SQL provides the DISTINCT keyword to remove duplicates from a SELECT statement. Third-party software: Several third-party software solutions are available to identify and remove duplicates from large data Feb 10, 2015 · I'm trying to remove all duplicates in a collection with ensureIndex and dropDups, but this method doesn't seem to work with arrays. Is there a better and fast way to remove duplicates in a collection? To delete all documents from a collection, pass an empty filter document {} to the MongoDB::Collection::delete_many() method. Nov 2, 2012 · For example, you could use aggregation as suggested on: MongoDB duplicate documents even after adding unique key. (For each duplicated document, I only want to save one, which can be arbitrarily chosen. users and demo2. scan every document in a collection, to select those documents that match the query statement. I have a collection with only 300 documents, how can I duplicate the records in an efficient way to fill up the collection with upto a million records? Also merging different collections won’t help because there is not a lot of documents in other collections as well. Nov 17, 2022 · Sing Ming Chen. the unique constraint and avoid inserting duplicates as in the below syntax −db. Don't use insert. categories, demo1. 6. Any help is Dec 16, 2015 · I have a large collection (~2. key in collection1 is not matching with _id in collection2. Simply change this value to change the field to look in. MongoDB remove duplicate Aug 9, 2016 · Link field contains same sequense of numbers in both documents, 84358. Compass provides the following collection information and functionality in the detailed view: Aug 21, 2014 · Imagine a collection posts with documents like this: to ask about how to remove duplicate array entries in a document field. Each document in a MongoDB collection has a unique _id field, which serves as the primary key. 23+), the operation errors if the sort argument is not a document. Here, duplicate insertio May 7, 2024 · Prerequisite : MongoDB Introduction Short Description : A MongoDB Database is a container for all the collections, where Collection is a bunch of MongoDB documents similar to tables in RDBMS and Document is made of fields similar to a tuple in RDBMS, but it has a dynamic schema here. getCollection('orders'). You can use a query to remove all matching documents. For descriptions of the fields, see Collation Document. Apr 18, 2022 · I am trying to create a unique index but it’s erroring because of duplicate documents I currently have. However, it can be achieved relatively simply using a combination of MongoDB commands. If the collation is unspecified but the collection has a default collation (see db. 7 million documents) in mongodb, and there are a lot of duplicates. remove(query); Be wary, though, if number of matching documents is high, your database might get less responsive. And seems dropDupes option Feb 4, 2019 · After the execution of aggregation pipeline, the theCollectionWithoutDuplicates collection contains a document for each group of original duplicated documents, with a new _id - you can verify the output, removing original collection (db. I have a large collection of about 300M documents and I want to add an unique index on a collection. Update will look for the document that matches your query, then it will modify the fields you want and then, you can tell it upsert:True if you want to insert if no document matches your query. Click a collection in the left navigation. How can I add the index and get rid of the duplicates? May 30, 2020 · I want to remove if there are multiple documents that contain the same name and the same value. ; Match those groups having records greater than 1. 12+, 3. insertOne({FirstName:Chris}); { acknowledged : true, insertedId : ObjectId(5e775c37bbc41e36cc3caea1) } > db. Match the number sequence in each document in the Link field (i. Something like this: Jul 12, 2024 · Explanation: The upsert operation might try to create a new document with an email that already exists, violating the unique index on the email field. Group all the records having similar name. We need exact duplicate document/records. Collection. Use db. Feb 3, 2024 · Basic Collection Cloning. I have about 400,000 documents, and I need to remove all duplicates using the id field. ; Then group again to project all the duplicate names as an array. key identifies duplicate records, you can ensure a unique index with the dropDups:true index creation option in MongoDB 2. 90 posts. e cusId 4 and 5 does not have duplicates should not show in the results but cusId 1 has duplicates so the result should have all the duplicates except the last inserted document to the collection You can find the list of duplicate names using the following aggregate pipeline:. Duplicating data can remove the need to perform joins across multiple collections, which can improve application performance. getCollection("Collection") . collection. theCollection. 6. How to take the duplicate records in mongodb. Now, I want to remove the duplicate documents from the collection. So for example right now I have the following collections: demo1. Apr 23, 2015 · Each document has a single word stored in the same format as above. Example: Duplicate Data in an E-Commerce Schema Nov 17, 2021 · Group all documents having the same value in field1; Match the groups that have more than one document; Project all groups that have more than one document; This particular query finds duplicate values in the field1 column. createCollection()), the operation uses the collation specified for the collection. In the documents we will have 100 attributes so we can not find documents based on few attributes. with reference to the above example, a document with key-value 'non_matching_key' should be delete from Apr 28, 2022 · We have total 7 documents/records out of 2 documents/records are duplicate. For a sharded cluster, if you use the drop() method and then create a new collection with the same name, you must either: Flush the cached routing table on every mongos using flushRouterConfig. Use the drop() method and then create a new collection with the same name. Assuming you want to permanently delete docs that contain a duplicate name + nodes entry from the collection, you can add a unique index with the dropDups: true option: db. Ask Question Asked 12 years, Fastest way to remove duplicate documents in mongodb. dropDups() To Remove Duplicate Documents: MongoDB Jan 16, 2015 · I have a large collection (~2. In this article, we will explore how to find documents by ID in MongoDB by covering concepts, and examples in The performance benefit for reads when data is duplicated. MongoDB collection When you click the Clone button, Compass opens the document insertion dialog with the same schema and values as the cloned document. For example, if I have a collection that looks like this: { "_i May 31, 2021 · collection2 document - {_id: 'key', action: {key1:'key1', }}, {_id: 'non_matching_key', action: {key1:'key1', }} Delete all the documents from collection2, where items. We need to divide the task into two parts to remove duplicate entries from the database. If the sort argument is not a document, the operation errors. Problem: I want to remove all duplicated documents. Open the collection in a new tab. Cloning a collection in MongoDB with a different name is not an inbuilt single command operation. When sorting on a field which contains duplicate values, documents containing those values may be returned in any order. 14+, and 3. When you embed related data in a single document, you may duplicate data between two collections. So I would like to achieve those steps: Loop over each document in the collection. Thanks Nov 8, 2020 · Lets say I have the next documents in the colecction sample: {_id: 1, comp_index1: "one", comp_index2: "AAA", field: "lots of text" } {_id: 2, comp_index1: &quot;two&q May 26, 2019 · Remove Duplicates; My current implementation of removing duplicates is as follows. MongoDB does not store documents in a collection in a particular order. 259 tags I am attempting to delete all the documents returned by an aggregation in Mongodb. users. ensureIndex({yourFieldName: 1}, {unique: true, dropDups: true})To understand the above syntax, let us create a collection with documents. . Oct 7, 2021 · Thanks for your response but the expected result should be the documents that are duplicated (i. Aug 2, 2022 · I’m trying to remove duplicates of documents, in the collection the collection have millions of records and duplicates data I assume have 100k records. Sing's log, a developer's blog. dropDups will delete all your duplicate documents when the ensureIndex operation is run Remove List Duplicates Reverse a String Add Two Numbers Python MongoDB Delete Document To delete all documents in a collection, Nov 12, 2020 · MongoDB - Find documents with earliest occurrence of duplicate value 2 Find documents between two dates, but include documents before first and after last result If you ever find yourself in a position where you need to remove duplicate entries on a MongoDB collection, as per version 3. How to remove duplicate record in MongoDB 3 x - To remove duplicate record, use aggregate(). Jan 22, 2021 · I want to clone a MongoDB collection and save it on the same server with a different name. aggregate Sep 4, 2016 · Remove duplicate documents based on field. Duplicating data lets your application query related information about multiple entities in a single query while logically separating entities in your model. db. so need to find those duplicate document/records and delete from same collection. Help me. findAndModify() updates the first document in the sort order specified by this argument. ) Minimal illustrative example: The documents all have the following fields (there are also other fields, but those are of no relevance here): Here we have 3 documents. The following example shows how to use this syntax with a Note that the allowDiskUse: true option is optional but will help mitigate out of memory issues as this aggregation can be a memory intensive operation if your collection size is large - so i recommend to always use it. drop()) and rename the new collection (db. Indexes support the efficient execution of queries in MongoDB. Use update with upsert=true. To remove the documents which were inserted earlier; I read that each document in collection is assigned an ObjectId that makes document unique; Question Optional. test. Mar 30, 2021 · I have an mongo instance (about 120GB RAM, 250GB SSD) running 4. The following example deletes all documents from the inventory collection: Sep 28, 2021 · I have written an Atlas Search query and wanted to test it’s performance for a million records/documents. from pymongo import MongoClient client = MongoCli Feb 19, 2019 · Assuming you're doing this using the mongo Shell, one approach could be to iterate a query cursor as follows:. MyCollection. I use the aggregate function to find multiple entries for the same email-> find all entries with that email and associated numbers and then output these to a new collection called duplicates using the following command: Apr 4, 2024 · In MongoDB, finding documents by their unique identifier (ID) is a fundamental operation that allows us to retrieve specific records efficiently. Here we will see how to find duplicate records in MongoDB. 10. Please change collectionName and the fields for _id , which are supposed to be unique, to your needs accordingly. Sep 22, 2017 · Here is the command to delete all the records of a collection in the MongoDB shell or MongoDB Compass shell (_MongoSH). To delete all documents from a collection, pass an empty filter document {} to the pymongo. ensureIndex({'code' : 1}, {unique : true, dropDups : true}) unique will ensure you will not have duplicates anymore. First and the last document has same value for “name” and “age” fields. To learn more about inserting documents, see Insert Documents. qkishqwg tnh jzeat tbsula clq cixrz otboqx sznm suwaqg btetfkad