Mongodb 如何强制执行唯一的数据库引用 ID?

Mongodb how to enforce a unique db reference id?

Mongodb 如何强制执行唯一的数据库引用 ID?

const LikeSchema = new mongoose.Schema({
    idOfPost: {
        type: mongoose.Schema.Types.ObjectId,
        ref: 'Post',
        required: true,
    },
    userWhoLiked: {
        type: mongoose.Schema.Types.ObjectId,
        ref: 'User',
        required: true,
        unique: true // This is not working? Why?
    },
    date=:{
        default: Date.now,
        required: true,
        type: Date,
    },

如何确保所有 userWhoLiked 字段都是唯一的?

您应该构建一个 unique index,然后在文档的 insert/update 具有重复 userWhoLiked 值的情况下,您将抛出重复键错误。