将多个内容CSS文件添加到CKEditor(Adding multiple content CSS files to CKEditor)

 您可以使用MongoDB聚合框架 。 
 
 这是一个查询，它会以所需的形式为您提供日期。 不过，我相信会有一些更好的和有效的方式来处理这个问题，但这是我想出的。 
 
db.collection.aggregate([
  {"$unwind":"$class"},
  {"$unwind":"$class.people"},
  {"$match": {
      "class.people.name":"Susan"
       }
  },
  {"$group":{
      "_id":"$class.people.name",
      "classes":{"$push":"$class.name"}
    }
  }
])
 
 结果： - 
 
{ "_id" : "Susan", "classes" : [ "class 1", "class 2" ] }
 
 在$unwind操作之前尝试$match ，以避免$unwind之前的管道中产生不必要的结果。 
 
 请参阅聚合管道优化以提高性能。 

You can make use of MongoDB aggregation framework. 
 
Here is a query which will give you the date in the desired form. However, I believe that there will be some better and efficient way to handle this but this is what I came up with.
 
db.collection.aggregate([
  {"$unwind":"$class"},
  {"$unwind":"$class.people"},
  {"$match": {
      "class.people.name":"Susan"
       }
  },
  {"$group":{
      "_id":"$class.people.name",
      "classes":{"$push":"$class.name"}
    }
  }
])
 
Result :-
 
{ "_id" : "Susan", "classes" : [ "class 1", "class 2" ] }
 
Try to $match before first $unwind operation to avoid the unnecessary results in the pipeline before $unwind.
 
Refer Aggregation Pipeline Optimization for improved performance.