抑制陣列

Question

這裏面嵌入文檔的領域是我遇到的情況爲例（假裝每個學校都有學生的陣列，並且只有1結果）：

db.students.find(_id: { $in: school.students }) 

{ 
    _id: 1, 
    zipcode: "63109", 
    students: [ 
      { name: "john", school: 102, age: 10 }, 
      { name: "jess", school: 102, age: 11 }, 
      { name: "jeff", school: 108, age: 15 } 
     ] 
} 

我怎麼會做類似的查詢忽略學生內部的學生陣列中的「學校」字段？

例如，我該如何讓結果看起來像這樣？

{ 
    _id: 1, 
    zipcode: "63109", 
    students: [ 
      { name: "john", age: 10 }, 
      { name: "jess", age: 11 }, 
      { name: "jeff", age: 15 } 
     ] 
} 

Answer 1

你可以嘗試下面的東西。使用投影來保持你喜歡的領域。

db.students.find({}, {zipcode:1,"students.name" :1,"students.age" : 1})