從mongodb中的子文檔計數數據與貓鼬

我想用嵌套的子文檔計數數據，我無法理解我如何得到我想要的（以及是否可能）。從mongodb中的子文檔計數數據與貓鼬

我有用於約會列表如下貓鼬模式：

var AppointmentSchema = new mongoose.Schema(
 
\t { 
 
\t \t clinic: { 
 
\t \t \t type: mongoose.Schema.Types.ObjectId, 
 
\t \t \t ref: 'Clinic', 
 
\t \t \t required: true, 
 
\t \t }, 
 
\t \t type: { 
 
\t \t \t type: mongoose.Schema.Types.ObjectId, 
 
\t \t \t ref: 'AppointmentType', 
 
\t \t \t required: true, 
 
\t \t } 
 
\t } 
 
); 
 

 
var ClinicSchema = new mongoose.Schema(
 
\t { 
 
\t \t name: { 
 
\t \t \t type: String, 
 
\t \t \t maxlength: 25, 
 
\t \t \t required: true, 
 
\t \t } 
 
\t } 
 
); 
 

 
var AppointmentTypeSchema = new mongoose.Schema(
 
\t { 
 
\t \t name: { 
 
\t \t \t type: String, 
 
\t \t \t minlength: 2, 
 
\t \t \t maxlength: 25, 
 
\t \t \t required: true, 
 
\t \t } 
 
\t } 
 
);

從約會的那個名單，我期待報告度量知道不同數量每個診所的預約類型。

到目前爲止，我只能夠使用下面的聚集，讓每類任用的計數不管診所：

db.appointments.aggregate(
 
    [ 
 
     { 
 
      $group: { 
 
       _id: '$type', //$type is the column name in collection 
 
       count: {$sum: 1} 
 
      } 
 
     }, 
 
     { 
 
      $sort: { count: -1 } 
 
     } 
 
    ] 
 
);

這回我下面的結果：

{ "_id" : ObjectId("5838ef21b19aee730b8ae6c8"), "count" : 5 } 
 
{ "_id" : ObjectId("5838efa4d695cb7839672417"), "count" : 3 } 
 
{ "_id" : ObjectId("5838efb4d695cb7839672419"), "count" : 3

但我想獲得情況如下內容：

{ 
 
\t { 
 
\t \t id: 1, 
 
\t \t name: "Name of the cliniC#1", 
 
\t \t count: [ 
 
\t \t \t { 
 
\t \t \t \t id: 10, 
 
\t \t \t \t name: "Appointment Type #10", 
 
\t \t \t \t count: 4, 
 
\t \t \t }, 
 
\t \t \t { 
 
\t \t \t \t id: 20, 
 
\t \t \t \t name: "Appointment Type #20", 
 
\t \t \t \t count: 1, 
 
\t \t \t } 
 
\t \t ] 
 
\t }, 
 
\t { 
 
\t \t id: 2, 
 
\t \t name: "Name of the cliniC#2", 
 
\t \t count: [ 
 
\t \t \t { 
 
\t \t \t \t id: 10, 
 
\t \t \t \t name: "Appointment Type #10", 
 
\t \t \t \t count: 5, 
 
\t \t \t }, 
 
\t \t \t { 
 
\t \t \t \t id: 20, 
 
\t \t \t \t name: "Appointment Type #20", 
 
\t \t \t \t count: 2, 
 
\t \t \t } 
 
\t \t ] 
 
\t } 
 
}

來源

2016-11-29 Stephan

下聚集查詢會給你一個類似的結果：

db.appointments.aggregate(
    [ 
     { 
      $group: { 
       _id: "$clinic", 
       count: { $push: "$type" } 
      } 

     }, 
     { 
      $project:{ 
       _id: 0, 
       id: "$_id._id", 
       name: "$_id.name", 
       "count": 1 
      } 
     } 
    ] 
).pretty();

輸出示例：

{ 
     "count" : [ 
       { 
         "_id" : ObjectId("583ecd06401ce04a0ca7e170"), 
         "name" : "Appointment Type 1" 
       }, 
       { 
         "_id" : ObjectId("583ecd09401ce04a0ca7e171"), 
         "name" : "Appointment Type 2" 
       }, 
       { 
         "_id" : ObjectId("583ecd0c401ce04a0ca7e172"), 
         "name" : "Appointment Type 3" 
       } 
     ], 
     "id" : ObjectId("583eccf6401ce04a0ca7e16d"), 
     "name" : "Clinic 1" 
} 
{ 
     "count" : [ 
       { 
         "_id" : ObjectId("583ecd06401ce04a0ca7e170"), 
         "name" : "Appointment Type 1" 
       }, 
       { 
         "_id" : ObjectId("583ecd0c401ce04a0ca7e172"), 
         "name" : "Appointment Type 3" 
       } 
     ], 
     "id" : ObjectId("583eccfd401ce04a0ca7e16e"), 
     "name" : "Clinic 2" 
} 
{ 
     "count" : [ 
       { 
         "_id" : ObjectId("583ecd06401ce04a0ca7e170"), 
         "name" : "Appointment Type 1" 
       } 
     ], 
     "id" : ObjectId("583ecd01401ce04a0ca7e16f"), 
     "name" : "Clinic 3" 
}

count: 4與count有什麼關係？

來源

2016-11-30 13:13:27

從mongodb中的子文檔計數數據與貓鼬

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