如何从MongoDB文档中完全删除字段?

问题描述

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

假设这是一个文档.如何从此集合中的所有文档中完全删除"words"?我希望所有文档都不含"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

尝试以下操作:如果您的收藏集是示例"

Try this: If your collection was 'example'

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

请参阅:

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

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，请确保添加{multi: true}.否则，它只会从找到的第一个文档中将其删除.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 /update/unset/

示例:

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

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