node.js - Mongoose 中的一对多关系

Question

我正在使用平均堆栈创建一个混合应用程序。我正在使用 nosql 在 mongoose 中创建数据库。我的数据库由两个表组成，一个是“donors”，另一个是“bloodGroup”。我的“bloodGroup”架构如下:

module.exports = function(mongoose) {
 var Schema = mongoose.Schema;  

  /* bloodGroup Schema */
  var bloodGroupSchema = new Schema({
   name: { type: String, required: true }
  });
}

我的“捐助者”架构如下:

/* Donor Schema */
var DonorSchema = new Schema({
 Name: { type: String, required: true },
 DOB: { type: Date, required: true, trim: true },
 Sex: { type: String },
 BloodGroupID: { type: Schema.Types.ObjectId, ref: 'BloodGroup', required: true },  
 ContactNo: { type: String, required: true },
 LocationId: { type: Schema.Types.ObjectId, ref: 'Location', required:true },
 EmailId: { type: String, required: true },
 Password: { type: String, required: true }
});

当许多献血者引用单一血型时，会报告 BloodGroup 对象 ID 错误。如何解决此问题？

Answer 1

您可以引用此链接获取文档:http://mongoosejs.com/docs/populate.html

Saving Refs

    /* Donor Schema */
    var DonorSchema = new Schema({
     _id : {type: Number},
     Name: { type: String, required: true },
     DOB: { type: Date, required: true, trim: true },
     Sex: { type: String },
     BloodGroupID: { type: Schema.Types.ObjectId, ref: 'BloodGroup', required: true },  
     ContactNo: { type: String, required: true },
     LocationId: { type: Schema.Types.ObjectId, ref: 'Location', required:true },
     EmailId: { type: String, required: true },
     Password: { type: String, required: true }
    });


    /* bloodGroup Schema */
   var bloodGroupSchema = new Schema({
       _bid :{ type: Number, ref: 'Donor' },
       name: { type: String, required: true }
   });


    module.exports = mongoose.model('Donor', DonorSchema);
    module.exports = mongoose.model('Blood', bloodGroupSchema);


    var vidya = new Donor({ _id: 0, name: 'Vidya', sex: 'F' }); 
        vidya.save(function (err) {
          if (err) return handleError(err);

          var blood = new BloodGroup({
            name: 'B+',
            _bid: vidya._id    // assign the _id from the Donor
          });

          blood.save(function (err) {
            if (err) return handleError(err);
            // thats it!
          });
        });