如何使用户的电子邮件在 mongoDB 中唯一？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/28514120/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to make user's email unique in mongoDB?
提问by Ishan
I am making a collection of user's data. This will be pretty basic consisting of user's email, user's password (hashed), and an array of strings.
我正在收集用户数据。这将是非常基本的，包括用户的电子邮件、用户的密码（散列）和一个字符串数组。
{
email: '[email protected]',
password: 'password hash',
arr: []
}
I want to make sure that there can't be two inserts with the same email.
I read that the _idof mongoDB is unique by default, and it uses some special data structure for improved performance.
我想确保不能有两个具有相同email. 我读到_idmongoDB 的默认情况下是唯一的，它使用一些特殊的数据结构来提高性能。
How can I make sure that the emailremains unique, and if possible can I leverage the performance benefits provided by the _idfield ?
我如何确保email保持唯一性，如果可能，我可以利用该_id领域提供的性能优势吗？
Edit: I also want to make sure that there are no nullvalues for emailand that there are no documents which do not contain the emailfield.
编辑：我还想确保没有null值，email并且没有不包含该email字段的文档。
采纳答案by Skooppa.com
You can do it by creating a unique index for your email field.
您可以通过为电子邮件字段创建唯一索引来实现。
http://docs.mongodb.org/manual/tutorial/create-a-unique-index/
http://docs.mongodb.org/manual/tutorial/create-a-unique-index/
Scott
斯科特
回答by achuth
回答by Mikko
Mongodb ensureIndexhas been deprecated, use createIndexinstead.
MongodbensureIndex已被弃用，请createIndex改用。
db.collection.createIndex( { email: 1 }, { unique: true } )
db.collection.createIndex( { email: 1 }, { unique: true } )
