如何在环回4中使模型在其架构中具有唯一值? [英] How to make a model in loopback 4 to have unique values in its schema?

问题描述

我正在尝试找到一种方法来具有与我放进去时一样的功能 唯一:在表达模式中为true.我该如何在回送4中完成此操作.我尝试在属性装饰器中放入unique true，但是它不起作用.

I am trying to find a way to have the same funtionality that happens when I put unique:true in express schema. How do I accomplish this in loopback 4. I tried putting unique true in the property decorator but it did not work.

@property({
    type: 'string',
    id: true,
    required: false,
    unique: true,
  })
  id: string;

这不起作用

推荐答案

@property装饰器借用了与LB3中相同的属性.假设我已经了解您的要求，则可以使用index属性在整个集合中强制字段的唯一性. 对于"id"之类的字段，属性装饰器将采用以下参数:

@property decorator in LB4 borrows the same properties as in LB3. Assuming that I have understood your requirements, you can make use of the index property to enforce the uniqueness of a field across the collection. For a field like 'id', the property decorator would take the following arguments:

@property({
    type: 'string',
    id: true,
    required: false,
    index: {
        unique: true
    }
  })
  id: string;

此外，如果您使用的是MongoDB生成的"id"，则无需显式实施唯一性，但以上内容适用于其他字段，例如电子邮件，用户名等.

Moreover, if you are using the 'id' generated by MongoDB, you do not need to enforce uniqueness explicitly but the above should work for other fields like email, username etc.

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