Mongoose 唯一验证器的行为与其他验证器不同

Question

在我的用户架构中，我有一个电子邮件字段定义如下：

...
email: {
    unique: [true, 'A user with that email address exists. The email must be unique.'],
    type: String,
    lowercase: true,
    required: [true, 'A user must have an email address']
},
...

当我在创建用户时将电子邮件留空时，我可以看到我在架构 required: [true, 'A user must have an email address'] 中定义的自定义错误消息。但是，如果我选择一个已被其他用户使用的电子邮件地址，我会收到一个不同的错误，我看不到我在 unique 字段 unique: [true, 'A user with that email address exists. The email must be unique.'] 中定义的自定义消息。

电子邮件为空时出错（我觉得很容易得到错误消息很有用）：required 请注意我的错误消息用户必须有一个电子邮件地址。

Error create { MongooseError: User validation failed
at ValidationError (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/error/validation.js:23:11)
at model.Document.invalidate (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/document.js:1486:32)
at /Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/document.js:1362:17
at validate (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/schematype.js:705:7)
at /Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/schematype.js:742:9
at Array.forEach (native)
at SchemaString.SchemaType.doValidate (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/schematype.js:710:19)
at /Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/document.js:1360:9
at _combinedTickCallback (internal/process/next_tick.js:67:7)
at process._tickCallback (internal/process/next_tick.js:98:9)
errors: 
   { email: 
      { MongooseError: A user must have an email address
      at ValidatorError (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/error/validator.js:24:11)
      at validate (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/schematype.js:704:13)
      at /Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/schematype.js:742:9
      at Array.forEach (native)
      at SchemaString.SchemaType.doValidate (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/schematype.js:710:19)
      at /Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongoose/lib/document.js:1360:9
      at _combinedTickCallback (internal/process/next_tick.js:67:7)
      at process._tickCallback (internal/process/next_tick.js:98:9)
    message: 'A user must have an email address',
    name: 'ValidatorError',
    properties: [Object],
    kind: 'required',
    path: 'email',
    value: '' } },
message: 'User validation failed',
name: 'ValidationError' }

电子邮件已被使用时出错：unique

Error create { MongoError: E11000 duplicate key error collection: stellium-io.users index: email_1 dup key: { : "john@doe.com" }
at Function.MongoError.create (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongodb-core/lib/error.js:31:11)
at toError (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongodb/lib/utils.js:114:22)
at /Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongodb/lib/collection.js:657:23
at handleCallback (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongodb/lib/utils.js:95:56)
at /Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongodb/lib/bulk/unordered.js:465:9
at handleCallback (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongodb/lib/utils.js:95:56)
at resultHandler (/Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongodb/lib/bulk/unordered.js:413:5)
at /Users/fleavamini/Projects/stellium/stellium.io/node_modules/mongodb-core/lib/connection/pool.js:455:18
at _combinedTickCallback (internal/process/next_tick.js:67:7)
at process._tickCallback (internal/process/next_tick.js:98:9)
name: 'MongoError',
message: 'E11000 duplicate key error collection: stellium-io.users index: email_1 dup key: { : "john@doe.com" }',
driver: true,
code: 11000,
index: 0,
errmsg: 'E11000 duplicate key error collection: stellium-io.users index: email_1 dup key: { : "john@doe.com" }',
getOperation: [Function],
toJSON: [Function],
toString: [Function] }

这是预期的行为吗？我希望能够在 unique 字段中获取我的自定义错误并将其返回给尝试创建新用户对象的用户。

Answer 1

Mongoose 中的唯一性不是验证参数（如必需），它告诉 Mongoose 在 MongoDB 中为该字段创建唯一索引。

唯一性约束完全在 MongoDB 服务器中处理。当您添加具有重复键的文档时，MongoDB 服务器将返回您正在显示的错误 (E11000...)。

如果您想创建自定义错误消息，您必须自己处理这些错误。 Mongoose 文档（搜索“错误处理中间件”）为您提供了如何创建自定义错误处理的示例：

schmea.post('save', function(error, doc, next) {
  if (error.name === 'MongoError' && error.code === 11000) {
    next(new Error('email must be unique'));
  } else {
    next(error);
  }
});

或者你可以使用这个插件mongoose-unique-validator

（尽管这并没有为您提供唯一性约束失败的特定字段）

Answer 2

唯一性约束完全在 MongoDB 服务器中处理。当您添加具有重复键的文档时，MongoDB 服务器将返回您所显示的错误 (E11000...)

如果您想创建自定义错误消息，您必须自己处理这些错误。

喜欢：

schmea.post('save',function(err,doc,next){
      if (err.name === 'MongoError' && err.code === 11000) {
    next(new Error('email must be unique'));
  } else {
    next(error);
  }
});