How to remove a field completely from a MongoDB document

Question

name   book       tags            words    abc   123            lat  33          long  22           Suppose this is a document  How do I remove  words  completely from all the documents in this collection  I want all documents to be without  words             name   book        tags             lat  33           long  22

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Starting Mongo 4 2  it s also possible to use a slightly different syntax        name   book   tags    words    abc    123    lat  33  long  22     db collection update         unset    tags words         many  true         name   book   tags    lat  33  long  22       The update method can also accept an aggregation pipeline  note the squared brackets signifying the use of an aggregation pipeline    This means the  unset operator being used is the aggregation one  as opposed to the  query  one   whose syntax takes an array of fields

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I was trying to do something similar to this but instead remove the column from an embedded document  It took me a while to find a solution and this was the first post I came across so I thought I would post this here for anyone else trying to do the same   So lets say instead your data looks like this        name   book     tags                words    abc   123          lat  33        long  22                words    def   456          lat  44        long  33               To remove the column words from the embedded document  do this    db example update      tags      exists   true         unset    tags     words   1       multi  true      or using the updateMany  db example updateMany      tags      exists   true         unset    tags     words   1       The  unset will only edit it if the value exists but it will not do a safe navigation  it wont check if tags exists first  so the exists is needed on the embedded document   This uses the all positional operator       which was introduced in version 3 6

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And for mongomapper     Document  Shutoff Field to remove  shutoff type   Shutoff collection update          unset    gt     shutoff type   1       multi   gt  true

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To remove or delete field in MongoDB   For single Record    db getCollection  userData   update       unset   pi  1     For Multi Record    db getCollection  userData   update       unset   pi  1     multi  true

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you can also do this in aggregation by using project at 3 4    project    tags words   0

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In the beginning  I did not get why the question has a bounty  I thought that the question has a nice answer and there is nothing to add   but then I noticed that the answer which was accepted and upvoted 15 times was actually wrong   Yes  you have to use  unset operator  but this unset is going to remove the words key which does not exist for a document for a collection  So basically it will do nothing   So you need to tell Mongo to look in the document tags and then in the words using dot notation  So the correct query is   db example update             unset    tags words  1      false  true     Just for the sake of completion  I will refer to another way of doing it  which is much worse  but this way you can change the field with any custom code  even based on another field from this document

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Try this  If your collection was  example  db example update       unset   words 1    false  true    Refer this  http   www mongodb org display DOCS Updating Updating- 24unset UPDATE  The above link no longer covers   unset ing  Be sure to add  multi  true  if you want to remove this field from all of the documents in the collection  otherwise  it will only remove it from the first document it finds that matches  See this for updated documentation  https   docs mongodb com manual reference operator update unset  Example  db example update       unset   words 1      multi  true

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By default  the update   method updates a single document  Set the Multi Parameter to update all documents that match the query criteria   Changed in version 3 6  Syntax     db collection update      lt query gt       lt update gt             upsert   lt boolean gt        multi   lt boolean gt        writeConcern   lt document gt        collation   lt document gt        arrayFilters     lt filterdocument1 gt                  Example    db getCollection  products   update      unset   translate 1  qordoba translation version 1     multi  true     In your example    db getCollection  products   update      unset    tags words   1      multi  true

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To reference a package and remove various  keys   try this  db  name1 name2 name3 Properties   remove           key     name key1             key     name key2             key     name key3

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Because I kept finding this page when looking for a way to remove a field using MongoEngine  I guess it might be helpful to post the MongoEngine way here too  Example objects all   update unset  tags  words 1

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db example updateMany       unset    tags words  1      We can also use this to update multiple documents

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The solution for PyMongo  Python mongo    db example update        unset     tags words  1    multi True

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name   book       tags            words    abc   123            lat  33          long  22          Ans   db tablename remove   tags words    abc   123

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In mongoDB shell this code might be helpful  db collection update       unset   fieldname   quot  quot

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Checking if  words  exists and then removing from the document      db users update   tags words     exists  true                                                 unset   tags words  1   false true     true indicates update multiple documents if matched

[mongodb] How to remove a field completely from a MongoDB document?

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