Mongodb find duplicates. Finding duplicate values in .

Mongodb find duplicates In the documents we will have 100 attributes so we can not find documents based on few attributes. Feb 3, 2024 · db. Basically my collection has this schema. Group your documents by your criteria (fields a and b). I don't know of any commands that will update your collection in-place, but you can certainly do it via temp storage. I did a research and found that aggregation needs to be used to do grouping and find respective count. For example if you have a collection or a model which is named "Employees" you need to do the following after connection to db. How can I remove a duplicate object from a MongoDB MongoDB find duplicates in an array How can we find the duplicates in an array of document similar to: I need to find if the document has duplicate record number in an array, like we have "number":"1" twice in this document. . This is my typical document : { "_id": { … Find duplicate records in MongoDB. When I say duplicates I don't mean that the whole document is the same. A MongoDB database is a type of database that gives you the ability to create applications that can perform much more than just CRUD operations, providing the ability to query, print, and update data, it supports many operators that can be used to find duplicates. Jun 4, 2021 · I am trying to find out how I can make a mongodb aggregation to delete duplicate documents according to a specific parameter. ensureIndex({name: 1, nodes: 1}, {unique: true, dropDups: true}) Sep 14, 2016 · I need to find records in this collection that contain duplicate values for the both the comment AND the url_key. In this illustration the entry_2 and Mar 8, 2022 · Find duplicate records in MongoDB. Mongo find duplicates for entries for two or more White Papers & Presentations. whatever email/record that exists will throw an exception where you catch and do whatever you want with the failed entries. Jan 1, 2025 · To find duplicate records in MongoDB based on an id and a datetime field, you can use the aggregation framework to group documents by these fields and then filter for groups having more than one document, indicating duplicates. Mongo find duplicates for entries for two or more fields. how to find duplicate records in mongo db query to Apr 28, 2022 · how to find and remove duplicates documents from mongodb using python. Sep 11, 2018 · Is there a way to find duplicate records ( all occurrences of the duplicates) in a mongo Db collection when queried by a particular field. Or should I just iterate over all records and Jan 22, 2021 · Find duplicate records in MongoDB. Feb 26, 2017 · Mongodb find duplicates where second column matches. Apr 23, 2022 · I would like to find all values that have one or more matching document, no matter if the value is in sig1 or sig2. 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. a == document2. for some network issues, we discovered duplicates Aug 28, 2018 · To prevent the duplicates being inserted you need a unique index which can be created in C# code:. I am using Spring-data. [{ "_id": ObjectId("578953db976cea724bbdbb60"), Mar 28, 2015 · MongoDB: Find documents but drop duplicates by key. You can find the list of duplicate names using the following aggregate pipeline: Group all the records having similar name . In this blog post which is part of the series "A Developer's Notes", we'd like to record useful MongoDB operations in regards of finding and removing duplicate documents, as thi Fast way to find duplicates on indexed column in mongodb. findDuplicateRecordsDemo. How do I query to find these results? As if i dont already know these are duplicates. 1 Check and remove duplicates in python MongoDB When specifying collation, the locale field is mandatory; all other collation fields are optional. I'd like to find all duplicates. I don't know which one will to be honest. MongoDB: find duplicates across multiple keys. The result will be a list of collection of duplicates. Count ignoring duplicate documents. with the same metadata and everything The following example uses the subset pattern to optimize access patterns for an online store. It gives only duplicated results with their duplicates count. ( It is best to create index on that field if your database is big ) Group based on user and tour to identify how many reviews user provided in same tour. How to find duplicate entries in collection using aggregation. CreateOne(indexDefinition, options); } Mar 20, 2020 · one way would be to first put a unique index on the email field of the collection. You can use the following syntax to find documents with duplicate values in MongoDB: Mar 11, 2022 · MongoDB: Find documents but drop duplicates by key. Is there a better and fast way to remove duplicates in a collection? Nov 16, 2018 · I want to find the duplicated document in my mongodb based on name, I have the following code: Avoid mongodb duplicate documents without using unique index. 10. 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. Email)); var indexDefinition = new IndexKeysDefinitionBuilder<Model>(). db. Feb 17, 2014 · A listing is a duplicate if the MlsId is not "" or "0" and another listing has that same MlsId. How would I find all duplicate listings and remove them? I started looking at MapReduce but couldn't find an example that fit my case. demo756. Sep 18, 2021 · I would like to extract from the collection the IDs of documents that have duplicate IDs of “drives” objects that are nested in the array that is in “streetModel”. Jan 7, 2016 · How do I structure my MongooseJS/MongoDB query to get total duplicates/occurrences of a particular field value? Aka: The total documents with custID of some value for all custIDs I can do this manually in command line: Apr 6, 2022 · Find duplicate values inside an array in Mongo DB but it can be present outside object. If you are certain that the source_references. The query to create a collection with a document is as follows −> db. By using distinct in mongodb, It will return list of distinct values. May 8, 2019 · I want to find duplicate documents in my mongodb database , and i have also achieved a portion of it , lets say my document is something like this { "_id" : ObjectId("5900b01b2ce12a2383328e61"), Jul 22, 2024 · // Step 2: Insert duplicates into the new collection duplicates. 2. So in the example above, the 2nd and 4th records would need to be removed. and I’ve been doing some tests however I couldnt find out why it allows duplicate values and a way to prevent it. To understand the concept, let us create a collection with the document. MongoDB - Find duplicated elements in record property. Finding duplicate values in a MongoDB array. Nov 20, 2020 · I want to find duplicates in the MongoDB atlas. 0. x. My collection is 'sales' Feb 15, 2021 · in mongodb you can solve this problem with "Aggregation Pipelines". Oct 30, 2021 · In this guide, we’ll implement easy-to-use operators to demonstrate examples of finding duplicate documents in MongoDB. MongoDB query to remove duplicate documents from a collection. MongoDB Find documents which have duplicate propety values. 20. Sep 27, 2021 · A protip by fsamir about mongodb. Dec 5, 2016 · MongoDB Find documents which have duplicate propety values. Dec 5, 2016 · There is a huge collection with 600. Apr 17, 2021 · Removing duplicates in mongodb with aggregate query. Ascending(field); Collection. Nov 2, 2012 · For example, you could use aggregation as suggested on: MongoDB duplicate documents even after adding unique key. How to find duplicate entries in Nov 19, 2010 · I have a collection of md5 in mongodb. Jun 5, 2015 · I got the below illustrated JSON in my MongoDB. Do you know any fast way to do that using map reduce. find(). May 28, 2015 · You could try to group the values by a (to get a mapping of a to list of entries with the according a) and then remove the entries from the mapping where the size of the value-list is greater 1/retain only the entries where the size of the value-list is 1. This is the code that is returning all the duplicate fields, I tried to add a new value in the match clause to filter by "course" but it didn't work and no value was returned. Sep 17, 2021 · you need to use "findAll({})" or just "find({})" with the collection name it will return an array object that will contain all the documents from the collection. We will use a set of operators with the aggregate() method to MongoDB find duplicates. { key: 'Find me' }, { key: 'find me' }, { key: 'Don't find me }, // just one document for this string { key: 'don't find me either } // just one document for this string Jul 30, 2020 · I have searched a lot, I could only find MongoDb query condition on comparing 2 fields and MongoDB: Unique and sparse compound indexes with sparse values, but in these questions they are looking for documents in which field a = field b, but I need to find document1. I am unable to get an aggregate query working where it can find duplicate records on a set of data in a date range. #mongodb. 35. docs; // Insert the duplicates (excluding one record) into the new collection db[newCollectionName]. The md5 column is indexed. Mar 18, 2020 · I have to find out duplicate values inside an array based on channel_id. But when through API multiple calls are happening within milliseconds the collection is allowing duplicate&hellip; Apr 11, 2014 · You can't do a reduction and eliminate duplicate documents using just find with MongoDB and a projection. 1. If the collation is unspecified but the collection has a default collation (see db. 5. test. So for this collection: { &quot;key&quot;: &quot;a&quot;, &quot;time&q Mar 3, 2022 · Hi, I have created a mongoose model as below, and set recordId field to “unique: true” to handle duplicate entry. The issue is that a few of them have multiple entries within the embedded array. Using this as test data (removed the _id): Sep 2, 2021 · Cant find duplicate values for array part in mongodb. Basically I’m writing data in bulk every few minutes and usually 1 minute of data is duplicate in the batch. Mongodb query to find all documents containing duplicate fields in array. /* 1 */ { &quo Dec 15, 2021 · Here we will see how to find duplicate records in MongoDB. Finding Duplicate Documents in MongoDB. remove({ /* criteria to match duplicates except one */ }); Output: This will remove all duplicate documents based on the specified criteria, leaving only unique documents. Sample Documents: Nov 16, 2016 · As per my understanding, you want to get distinct results which should eliminates the duplicate id in that collection. Don't use insert. Jul 9, 2016 · 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 Apr 4, 2022 · I have a data set that I want to find the duplicates with the same values in multiple rows. Sep 10, 2015 · Please, search for other similar questions before posting your own. collection. MongoDB's aggregation features make it achievable by allowing customization and provide flexibility as to how documents are grouped together and filtered. Every position will hold together a group of duplicates. For instance I have a data set that contains 12 different rows and I know the bottom 2 rows have similar values besides the _id and title values. So not only matching all the documents that have the same sig1 or sig2, but also the two documents above, because the first's sig2 is the same as the second's sig1. I can easily generate (using aggregate) duplicate records for the same, single, key (eg: comment), but I can't figure out how to group by/aggregate for multiple keys. MongoDB - duplicate documents removal. If you need a document to contain duplicate field names and you cannot alter this schema, MongoDB might not be the right database solution for you. Feb 16, 2023 · In this blog post we record useful MongoDB operations in regards of finding and removing duplicate documents, as this is a common problem developers face. Remove Duplicates on mongodb. Are you tired of dealing with duplicate data in your MongoDB collection? 🔄 It's time to put an end to the confusion and clutter! In this blog post, we'll dive deep into the world of MongoDB and unravel the mystery of finding duplicate records. I did use aggregation to delete those duplicates, but it is slow and is not ideal when we deploy it to prod. I got several hundred entries. Aug 5, 2020 · I have below collection, need to find duplicate records in mongo, how can we find that as below is one sample of collection we have around more then 10000 records of collections. May 7, 2024 · In this article, we'll explore how to remove duplicates using the $unionWith aggregation stage in MongoDB. i tried this method for one of requirement that worked fine. There is a similar question in SO: Mongo find duplicates for entries for two or more fields Nov 17, 2016 · MongoDB Find documents which have duplicate propety values. 3. Please change collectionName and the fields for _id , which are supposed to be unique, to your needs accordingly. Apr 4, 2024 · Duplicates in a MongoDB collection can lead to data inconsistency and slow query performance. Try Teams for free Explore Teams Jul 17, 2016 · I'm trying to find a way to find and remove duplicate object with the same field in a subdocument array. Share Improve this answer MongoDB -- Find duplicate documents by multiple keys. We'll cover the concepts, syntax, and practical examples to demonstrate its usage and effectiveness. forEach(group => { // Remove one document from the list of duplicates to keep in the original collection const [docToKeep, docsToMove] = group. In my collection I have duplicate registers with this key. The `duplicates` collection will have a `_id` field that corresponds to the value of the `email` field for the duplicate record and a `count` field that contains the number of duplicate records that have the same `email` address. Find number of duplicates documents. distinct("id"); ["580a2eb915a0161010c2a562", "580a2eb915a0161010c2bf572"] So you should look into mongodb aggregation Jul 1, 2020 · Check for duplicates in an array in MongoDB - To check for duplicates in an array, use aggregate() in MongoDB. MongoDb: Find exact array match with duplicates. Method 2: Using Aggregate to Find Duplicates. I have seen examples for finding duplicates but they didn't take two conditions as I understand it. Attempt also to show us what you have done. You interate over the list ignoring the first element of each every group to preserve it, and delete the rest. How to Find Duplicate Elements in a array (One Document)? 0. The idea would be that if two documents had the same "should_be_unique" value, and both had "dev_type" set to "Bar," then the total for "Bar" would be 6 instead of 7, reducing as a result of the duplicate. For descriptions of the fields, see Collation Document. 13. The aggregation framework provides a powerful way to process data and can be used to identify and delete duplicates. Use update with upsert=true. I tried restarting the database, and rebuilding an index involving 'a_boolean_key', with the same results. Is it possible to query Mongodb in such a way that the result will be : [myNetwork1,myNetwork2] right now I only managed to return [myNetwork1,myNetwork2,myNetwork1] I need a list of unique networkIDs to populate an autocomplete select2 component. How to take the duplicate Nov 30, 2018 · Finding duplicate values in your database can be difficult, especially if you have millions of documents in the collection. 4. Match those groups having records greater than 1 . Feb 18, 2019 · First add a group stage which will group according to the parameters you want to group (in this case a,b and c) Then find the values which have more than 1 occurrence of the parameters you grouped Jun 2, 2017 · I've tried a few options, but for the best of me I can't figure out the cleanest way to alter such a query while also eliminating duplicates. The find commands won't work as you need remember that it's returning a cursor to the client and as such, can't reduce the results to only those documents that are unique without a secondary pass. 6 or older: 📝 Tech Blog: Unraveling Duplicate Records in MongoDB. 241. Jan 17, 2023 · How to Find Duplicates in MongoDB. 000 documents. Jan 24, 2022 · In the MongoDB I want to search for all duplicates on a certain field ownersEmailAddress with or without upper letters (any combination of letter). insertOne({SubjectN Nov 3, 2021 · MongoDB: Find documents but drop duplicates by key. Removing duplicates in mongodb with aggregate query. Therefore, it's essential to identify and handle duplicates effectively to maintain data integrity. As I may have up to 50K documents I would prefer mongoDb to filter the results at the query level. I'm using 3. Oct 30, 2021 · Finding duplicate documents is challenging in MongoDB. class MyModel field :name, String # "My Object name" field :slugs, Array # ["my-object-name"] end Oct 5, 2017 · Find all duplicate documents in a MongoDB collection by a key field. Indexes. Feb 16, 2023 · Use the following MongoDB operations to identify duplicate documents in your collections, and remove them safely. I am working with mongoid, so my model Looks like this:. ORIGINAL ANSWER: It should be noted that searching with regex's case insensitive /i means that mongodb cannot search by index, so queries against large datasets can take a long time. Finding duplicate values in Jul 3, 2020 · Finding duplicate documents before creating unique - MongoDB Loading The following example uses the subset pattern to optimize access patterns for an online store. insertOne({StudentFirstName:John}); { acknowled Jan 28, 2022 · Match the user you need to search for duplicates. We have total 7 documents/records out of 2 documents/records are duplicate. public void CreateIndex() { var options = new CreateIndexOptions() { Unique = true }; var field = new StringFieldDefinition<Model>(nameof(Model. In this article, we'll explore various methods of how to find duplicates in MongoDB collections and discuss how to use them with practical examples and Oct 18, 2021 · In this post, I describe how to find duplicated documents in a MongoDB collection using a query or a GUI. Mongo Query to get duplicate entry from sub document array. Jul 30, 2019 · Find duplicate records in MongoDB - You can use the aggregate framework to find duplicate records in MongoDB. insertMany(docsToMove); }); Nov 6, 2023 · Finding duplicate documents in MongoDB can be done by using the Aggregation Pipeline to group documents based on criteria such as values of one or more fields and then counting the number of documents in each group. There are plenty of resources out there to help you with this. Nov 29, 2022 · Hi @alexbevi the results are exactly what I was looking for. Leverage _id and queries to pinpoint duplicates; Aggregation pipelines to scalably detect duplicates; Removing Duplicates Aug 20, 2021 · I need to find the duplicates entries for the "person" field, but I need to filter those values using the "course" value. I have accidently imported some documents, which now have duplicate "slugs" . Delete duplicate entries inside list by combination of fields with Jun 23, 2017 · Find all duplicate documents in a MongoDB collection by a key field. please try this by chagning as you need var names. Jan 12, 2024 · Discover duplicates handling breaking points before customers do! Let‘s Recap. Remove duplicate documents based on field. In the mongodb compass when I known the value i can use 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:. Thank you so much! However, with our database it doesn’t really work, Maybe i wasn’t clear enough before but the collection has all logins so with your query it will just add the same user multiple times on all ips if the user have logged in more than once? Dec 8, 2009 · UPDATE: The original answer is now obsolete. We‘ve covered a ton of ground around efficiently finding, removing, preventing, and testing duplicates in MongoDB: Finding Duplicates. Consider an application where when user views a product, the application displays the product's information and five most recent reviews. I have fetched the issues from Github API and inserted them into the database by making same requests multiple times to make duplicates. Coderwall Ruby Python JavaScript Front-End Tools iOS. key identifies duplicate records, you can ensure a unique index with the dropDups:true index creation option in MongoDB 2. PersonDuplicate. Check duplicates of certain field for documents array with inner array. More Tips MongoDB: find duplicates in a field. Find duplicate records in MongoDB. You pick the field which is replicated for the aggregation. so need to find those duplicate document/records and delete from same collection. You need to implement this pipeline in "Mongodb Java Driver". May 26, 2019 · Remove Duplicates; My current implementation of removing duplicates is as follows. Webinars, white papers, data sheet and more Jan 13, 2022 · Find duplicate records in MongoDB. How to get all duplicates documents in mongodb collection? 2. For this example, I am using Github Public Issues API. getCollection('posts'). 2 Mar 31, 2020 · New to Mongo, have found lots of examples of removing dupes from arrays of strings using the aggregation framework, but am wondering if possible to remove dupes from array of objects based on a fie Dec 1, 2021 · Hello everyone, I’ve been using influxdb for time series for the last past year but I wanted to try mongo time series recently. createCollection()), the operation uses the collation specified for the collection. Mongodb now supports advanced full text searching, with many features. This will find every user with a username, make the user names lower case, then group them by username and display the usernames that have a count greater than 1. Let us create a collection with documents −> db. Dec 1, 2021 · mongodb find duplicates in array across documents. 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: Jan 11, 2016 · My solution was also using aggregate. Check duplicates of certain field for Nov 12, 2020 · I want to find all the duplicated entries in this collection that have the same orderId after 1st November 2020. How to merge a collection field into another Jul 13, 2012 · Ask questions, find answers and collaborate at work with Stack Overflow for Teams. These duplicates differs only in first letter upper/lower case. then insert records in a try/catch block. Remove all Duplicates except the most recent document. by Erma Khan January 17, 2023. Load 7 more related questions Show fewer related questions Sorted by: Reset to default Aug 1, 2022 · Hi Team, We’re trying to find duplicates methods in our collection with about 2 or 3 millions of documents, we have tried this way but this seems slow and cannot be ideal when deploying to production, do you know what’s the best and fastest way to delete duplicate records with million of data. ensureIndex({"contact_id": 1}, {unique: true, dropDups: true}) But did not work, because the function dropDups is no longer available in MongoDB 3. I have developed the following query but results are not as expected. MongoDB query to find document with duplicate value in array. insertOne({SubjectName:[MySQL,MongoDB,Java]}); { acknowledged : true, insertedId : ObjectId(5eb01e0d5637cd592b2a4add) } > db. Nov 17, 2021 · This tutorial explains how to find duplicate values in MongoDB, including several examples. Once you find the duplicates, you can easily remove those from Mongo collection. I found this through Googling "mongodb find duplicate values array" in under a minute. a Feb 9, 2022 · That is, there aren't actually duplicate documents with the same _id-- it's just an issue with the . Unfortunatly there are duplicates, which I want to find. Feb 5, 2018 · InvalidOperationException: Duplicate element name 'DuplicateCol' As CodeFuller said, MongoDB document keys should be unique. May 30, 2020 · i'm not sure about mongo but using the node you can remove duplicates. How can I remove duplicates, resulting in just one register? I already tried: db. For example I have the following documents: Feb 5, 2022 · What I want is to find documents but drop duplicates by key and retrieve only the updated document (by a date field). MongoDB remove duplicate subdocuments inside array based on a specific field. 1 MongoDB Find documents which have duplicate propety values. Aug 9, 2016 · Ask questions, find answers and collaborate at work with Stack Overflow for Teams. Aug 26, 2021 · Find duplicates across multiple MongoDb collections. mdbgt avmac pahgf qcjvgzx bhoipl glbs egulegl nrb eayp nxc