MongoDB – 基于对象数组的项目数据

huangapple
go评论97阅读模式
英文:

MongoDB - Project data based on array of objects

问题

我有两位家长的学生数据：

  1. {
  2.   _id: ObjectId('643f8a6773a92fb1552e4c89'),
  3.   studentName: 'Peter Jackson',
  4.   studentId: 'SID1001',
  5.   grade: 2,
  6.   gender: 'Male',
  7.   parentDetails: [
  8.     {
  9.         _id: ObjectId('63fee5a42f60946679146768'),
  10.         name: 'Jackson Steve',
  11.         email: 'jack.steve@gmail.com',
  12.         mobile: 'xxxxxxxxxx',
  13.         relation: 'Father'
  14.     },
  15.     {
  16.         _id: ObjectId('6447c1ba22670472ed4b29cc'),
  17.         name: 'Amenda Jackson',
  18.         email: 'amenda.jack@gmail.com',
  19.         mobile: 'xxxxxxxxxx',
  20.         relation: 'Mother'
  21.     }
  22.   ]
  23. }

我需要根据每个家长显示学生数据，如下所示：

  1. [
  2.   {
  3.     studentId: 'SID1001',
  4.     studentName: 'Peter Jackson',
  5.     grade: 2,
  6.     parentName: 'Jackson Steve',
  7.     parentEmail: 'jack.steve@gmail.com',
  8.     relation: 'Father'
  9.   },
  10.   {
  11.     studentId: 'SID1001',
  12.     studentName: 'Peter Jackson',
  13.     grade: 2,
  14.     parentName: 'Amenda Jackson',
  15.     parentEmail: 'amenda.jack@gmail.com',
  16.     relation: 'Mother'
  17.   }
  18. ]

需要显示每个家长的详细信息以及他们的子女详细信息。
需要一些有价值的帮助。

英文:

I am having student data with two parents:

  1. {
  2.   _id: ObjectId('643f8a6773a92fb1552e4c89'),
  3.   studentName: 'Peter Jackson',
  4.   studentId: 'SID1001',
  5.   grade: 2,
  6.   gender: 'Male',
  7.   parentDetails: [
  8.     {
  9.         _id: ObjectId('63fee5a42f60946679146768'),
  10.         name: 'Jackson Steve',
  11.         email: 'jack.steve@gmail.com',
  12.         mobile: 'xxxxxxxxxx',
  13.         relation: 'Father'
  14.     },
  15.     {
  16.         _id: ObjectId('6447c1ba22670472ed4b29cc'),
  17.         name: 'Amenda Jackson',
  18.         email: 'amenda.jack@gmail.com',
  19.         mobile: 'xxxxxxxxxx',
  20.         relation: 'Mother'
  21.     }
  22.   ]
  23. }

I need to show the student data based on each parent like below:

  1. [
  2.   {
  3.     studentId: 'SID1001',
  4.     studentName: 'Peter Jackson',
  5.     grade: 2,
  6.     parentName: 'Jackson Steve',
  7.     parentEmail: 'jack.steve@gmail.com',
  8.     relation: 'Father'
  9.   },
  10.   {
  11.     studentId: 'SID1001',
  12.     studentName: 'Peter Jackson',
  13.     grade: 2,
  14.     parentName: 'Amenda Jackson',
  15.     parentEmail: 'amenda.jack@gmail.com',
  16.     relation: 'Mother'
  17.   }
  18. ]

Need to show individual parent details with their child details.
Need some valuable help.

答案1

得分: 3

  1. $unwind - 将 parentDetails 数组拆分为多个文档。

  2. $project - 对输出文档进行修饰以获得所需的输出。

  1. db.collection.aggregate([
  2.   {
  3.     $unwind: "$parentDetails"
  4.   },
  5.   {
  6.     $project: {
  7.       studentName: 1,
  8.       studentId: 1,
  9.       grade: 1,
  10.       parentName: "$parentDetails.name",
  11.       parentEmail: "$parentDetails.email",
  12.       relation: "$parentDetails.relation"
  13.     }
  14.   }
  15. ])

在Mongo Playground中查看演示

英文:

  1. $unwind - Deconstruct the parentDetails array into multiple documents.

  2. $project - Decorate the output document to desired output.

  1. db.collection.aggregate([
  2.   {
  3.     $unwind: "$parentDetails"
  4.   },
  5.   {
  6.     $project: {
  7.       studentName: 1,
  8.       studentId: 1,
  9.       grade: 1,
  10.       parentName: "$parentDetails.name",
  11.       parentEmail: "$parentDetails.email",
  12.       relation: "$parentDetails.relation"
  13.     }
  14.   }
  15. ])

Demo @ Mongo Playground

huangapple
  • 本文由 发表于 2023年7月6日 11:43:47
  • 转载请务必保留本文链接：https://go.coder-hub.com/76625357.html
  • aggregation-framework
  • arrays
  • mongodb
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定