node.js Mongoose 模式可选字段
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/24942037/
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
Mongoose schema optional fields
提问by HarveyBrCo
I have a user schema with mongoose in nodejs like this
我在 nodejs 中有一个带有 mongoose 的用户架构，就像这样
userschema = mongoose.Schema({
org: String,
username: String,
fullname: String,
password: String,
email: String
});
Except sometimes I need to add some more fields.
除了有时我需要添加更多字段。
The main question is: Can I have optional fields in a monogoose schema?
主要问题是：我可以在monogoose 模式中有可选字段吗？
回答by Talha Awan
In addition to optional(default) and required, a field can also be conditionally required, based on one or more of the other fields.
除了optional（默认）和required 之外，还可以根据一个或多个其他字段有条件地要求字段。
For example, require password only if email exists:
例如，仅当电子邮件存在时才需要密码：
var userschema = mongoose.Schema({
org: String,
username: String,
fullname: String,
password: {
type: String,
required: function(){
return this.email? true : false
}
},
email: String
});
回答by JohnnyHK
All fields in a mongoose schema are optional by default (besides _id, of course).
默认情况下_id，猫鼬模式中的所有字段都是可选的（当然，除了）。
A field is only required if you add required: trueto its definition.
仅当您添加required: true到其定义时才需要该字段。
So define your schema as the superset of all possible fields, adding required: trueto the fields that are required.
因此，将您的架构定义为所有可能字段的超集，添加required: true到所需的字段中。
