如何用子文档数组更新MongoDB文档 [英] How to update MongoDB documents with arrays of sub-documents
问题描述
var mongoose = require（'mongoose'）;
var Schema = mongoose.Schema;
var ObjectId = Schema.Types.ObjectId;
// SUBJECT collection
var subjectSchema = new Schema（{$ b $ name：{type：String，required：true}，
category：{type：String， required：true}
}）;
var Subject = mongoose.model（'Subject'，subjectSchema）;
学生集合
var studentSchema =新模式（{
name：{type：String，required：true}，
grade：{type：Number， required：true}
}）;
var Student = mongoose.model（'Student'，studentSchema）;
$ b $ // PERFORMANCE collection
var performanceSchema = new Schema（{
subjectId：{type：ObjectId，ref：Subject.modelName，required：true}，
score ：{type：Number，required：true}，
maximum：{type：Number，required：true}，
grade：{type：String，required：true}
}）;
var Performance = mongoose.model（'Performance'，performanceSchema）;
$ b $ // *注意*：这只是用作子文档模式，而不是作为集合
var classStudentSchema = new Schema（{
studentId：{type ：ObjectId，ref：Student.modelName，required：true}，
performance：[performanceSchema]
}，{_id：false}）;
CLASS集合
var classSchema =新架构（{
name：{type：String，required：true}，
scores [classStudentSchema]
}）;
var Class = mongoose.model（'Class'，classSchema）;
{
_id：ObjectId（57758f15f68da08c254ebee1），
name：Grade 5 - Section A，
scores：[{$ b $studentId：ObjectId（5776bd36ffc8227405d364d2），
performance bsubjectId：ObjectId（577694ecbf6f3a781759c54a），
score：86，
maximum：100，
grade：B +
}，{
subjectId：ObjectId（5776ffe1804540e29c602a62），
score：74，
maximum：100，
grade：A-
}]
}，{
studentId：ObjectId（5776bd36ffc8227405d364d5），
performance：[{
subjectId：ObjectId（577694ecbf6f3a781759c54a
score：94，
maximum：100，
grade：A
}，{
subjectId：ObjectId（5776ffe1804540e29c602a62 ），
score：81，
maximum：100，
grade：A
}]
}]
}
我可以使用下面的代码检索现有的类文档并添加学生分数：
$ b $ pre $
Class.findOne（{name：'Grade 5 - Section A'}，function（err，class）{
if（err ）扔err;
Student.findOne（{name：'John Doe'}，function（err，student）{
if（err）throw err;
class.scores.push（{
studentId：student.id
}）;
};
}）;
但是，如何添加/更新/删除特定学生的表现？我需要能够通过以下方式与类集合进行交互：
分数数组中的特定元素）
scores [n] .performance 数组中的特定元素;添加，附加到相同的数组。
有几种方法可以做到这一点我会回答点通过点
检索所有学生或特定学生的分数（检索分数数组中的特定元素）
Class.findOne（{name：'Grade 5 - Section A'}）
.populate（'scores.studentId'）
.exec（function（err，class）{
if（err）throw err;
// now class.scores.studentId is ObjectStudent
//因此，所有学生的所有分数
}）;
添加/更新/删除特定学生的分数更新或删除，检索scores [n] .performance数组中的特定元素;添加，附加到同一个数组。 code> Class.findOneAndUpdate（{name：'Grade 5 - Section A' 我希望有帮助 I am working with a MongoDB database whose collections model classes, students, subjects, and [academic] performance. Below are the Mongoose based schema and models: The I was able to retrieve an existing class document and add a student to it's scores using the following code: But how do I add/update/delete that particular student's performance? I need to be able to interact with the
，'scores.studentId'：ObjectId（'5776bd36ffc8227405d364d2'）
，'scores.performance.subjectId'：ObjectId （$ 57
$ {$ set： b}）;
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var ObjectId = Schema.Types.ObjectId;
// SUBJECT collection
var subjectSchema = new Schema({
name : { type: String, required: true },
category : { type: String, required: true }
});
var Subject = mongoose.model('Subject', subjectSchema);
// STUDENT collection
var studentSchema = new Schema({
name : { type: String, required: true },
grade : { type: Number, required: true }
});
var Student = mongoose.model('Student', studentSchema);
// PERFORMANCE collection
var performanceSchema = new Schema({
subjectId : { type: ObjectId, ref: Subject.modelName, required: true },
score : { type: Number, required: true },
maximum : { type: Number, required: true },
grade : { type: String, required: true }
});
var Performance = mongoose.model('Performance', performanceSchema);
// *Note*: This is just to use as a sub-document schema, and not as a collection
var classStudentSchema = new Schema({
studentId : { type: ObjectId, ref: Student.modelName, required: true },
performance : [performanceSchema]
}, { _id: false });
// CLASS collection
var classSchema = new Schema({
name : { type: String, required: true },
scores : [classStudentSchema]
});
var Class = mongoose.model('Class', classSchema);
class collection's documents are the most complex of the lot; an example document would be:{
"_id" : ObjectId("57758f15f68da08c254ebee1"),
"name" : "Grade 5 - Section A",
"scores" : [{
"studentId" : ObjectId("5776bd36ffc8227405d364d2"),
"performance": [{
"subjectId" : ObjectId("577694ecbf6f3a781759c54a"),
"score" : 86,
"maximum" : 100,
"grade" : "B+"
}, {
"subjectId" : ObjectId("5776ffe1804540e29c602a62"),
"score" : 74,
"maximum" : 100,
"grade" : "A-"
}]
}, {
"studentId" : ObjectId("5776bd36ffc8227405d364d5"),
"performance": [{
"subjectId" : ObjectId("577694ecbf6f3a781759c54a"),
"score" : 94,
"maximum" : 100,
"grade" : "A"
}, {
"subjectId" : ObjectId("5776ffe1804540e29c602a62"),
"score" : 81,
"maximum" : 100,
"grade" : "A"
}]
}]
}
Class.findOne({ name: 'Grade 5 - Section A' }, function(err, class) {
if (err) throw err;
Student.findOne({ name: 'John Doe' }, function(err, student) {
if (err) throw err;
class.scores.push({
studentId: student.id
});
};
});
class collection in the following ways:
scores array)scores[n].performance array; for add, append to the same array.
There are a few way to do this I'll answer point by point
Retrieve the scores for all students, or for a specific student (retrieve specific element in the scores array)
Class.findOne({ name: 'Grade 5 - Section A'})
.populate('scores.studentId')
.exec(function(err, class) {
if (err) throw err;
//now class.scores.studentId becomes ObjectStudent
//hence you have all scores for all students
});
Add/ update/ delete a specific student's score, for a specific subject (in case of update or delete, retrieve a specific element in the scores[n].performance array; for add, append to the same array.
Class.findOneAndUpdate({name: 'Grade 5 - Section A'
,'scores.studentId': ObjectId('5776bd36ffc8227405d364d2')
, 'scores.performance.subjectId' : ObjectId('577694ecbf6f3a781759c54a')}
, {$set: {scores.performance. score: 50}}
, function(err, data) {
if (err) throw err
});
I hope that helps
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