展开，但在每个结果行中保留原始数组

Question

{ 
    name: 'John Smith',
    appointments: [
        {date: 'date1', type: 'type one'},
        {date: 'date2', type: 'type two'}
    ]
},
{ 
    name: 'Michael Jackson',
    appointments: [
        {date: 'date3', type: 'type three'},
    ]
}

因此我需要以下内容：

{ 
    name: 'John Smith',
    appointment: {date: 'date1', type: 'type one'},
    appointments: [
        {date: 'date1', type: 'type one'},
        {date: 'date2', type: 'type two'}
    ]
},
{ 
    name: 'John Smith',
    appointment: {date: 'date2', type: 'type two'},
    appointments: [
        {date: 'date1', type: 'type one'},
        {date: 'date2', type: 'type two'}
    ]
},
{ 
    name: 'Michael Jackson',
    appointment: {date: 'date3', type: 'type three'},
    appointments: [
        {date: 'date3', type: 'type three'},
    ]
}

是否有任何形式的聚合展开可以将 appointments 展开为 appointment，但仍会在每个结果记录中保留原始约会数组？

感谢任何帮助。

Answer 1

• $addFields 在 appointment
中克隆 appointments
• $unwind解构appointment数组

db.collection.aggregate([
  { $addFields: { appointment: "$appointments" } },
  { $unwind: "$appointment" }
])

Playground