如何从Mongo中完全删除字段？ [英] How do I remove a field completely from Mongo?

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单词？我想要所有的文件没有字：

Suppose this is a document. How do I remove "words" completely from all the documents in this collection? I want all the documents to be without "words":

 { 
      name: 'book',
      tags: {
        lat: 33,
        long: 22
      }
}

$ b b

推荐答案

尝试：如果您的集合是example

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

UPDATE ：

上述链接不再涵盖'$取消设置。下面的Nic Cottrell的评论是现在的方式。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，它将只从它发现匹配的第一个文档中删除它。查看更新的文档：

The above link no longer covers '$unset'ing. Nic Cottrell's comment below is the way to go now. 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/

示例：

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

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