如何从 MongoDB 文档中完全删除字段? [英] How to remove a field completely from a MongoDB document?

问题描述

{ 
    name: 'book',
    tags: {
        words: ['abc','123'],
        lat: 33,
        long: 22
    }
}

假设这是一个文档.如何从该集合中的所有文档中完全删除words"?我希望所有文档都没有words":

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
     }
}

推荐答案

试试这个:如果你的收藏是示例"

Try this: If your collection was 'example'

db.example.update({}, {$unset: {words:1}}, false, true);

参考:

http://www.mongodb.org/display/DOCS/Updating#Updating-%24unset

更新:

以上链接不再涵盖$unset".如果要从集合中的所有文档中删除此字段，请务必添加 {multi: true}；否则，它只会从它找到匹配的第一个文档中删除它.请参阅此以获取更新的文档:

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/更新/未设置/

示例:

db.example.update({}, {$unset: {words:1}} , {multi: true});

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