$rename操作邏輯執行$unset 老名稱和新的名稱，然後執行 $set新名稱執行。因此，操作可能不保留文件中欄位的順序; 即重新命名的欄位可以在文件內移動。

1、重新命名欄位：一級欄位

格式：

db.students.updateMany( {}, { $rename: { "nmae": "name" } } )

eg：

#原集合
{
  "_id": 1,
  "alias": [ "The American Cincinnatus", "The American Fabius" ],
  "mobile": "555-555-5555
 
",
  "nmae": { "first" : "george", "last" : "washington" }
}

{
  "_id": 2,
  "alias": [ "My dearest friend" ],
  "mobile": "222-222-2222",
  "nmae": { "first" : "abigail", "last" : "adams" }
}

{
  "_id": 3,
  "alias": [ "Amazing grace" ],
  "mobile": "111-111-1111",
  "nmae": { "first" : "grace", "
 
last" : "hopper" }
}

#修改：批量把所有的nmae 欄位改成name,也可以在第一個花括號裡面指定修改哪一個id記錄的nmae
db.students.updateMany( {}, { $rename: { "nmae": "name" } } )

#輸出：
{
  "_id": 1,
  "alias": [ "The American Cincinnatus", "The American Fabius" ],
  "mobile": "555-555-5555",
  "name": { "first" : "george", "last" : "washington
 
" }
}

{
   "_id" : 2,
   "alias" : [ "My dearest friend" ],
   "mobile" : "222-222-2222",
   "name" : { "first" : "abigail", "last" : "adams" }
}

{ "_id" : 3,
  "alias" : [ "Amazing grace" ],
  "mobile" : "111-111-1111",
  "name" : { "first" : "grace", "last" : "hopper" } }

2、重新命名嵌入文件中的欄位

eg：

#元集合：
{
  "_id": 1,
  "alias": [ "The American Cincinnatus", "The American Fabius" ],
  "mobile": "555-555-5555",
  "name": { "first" : "george", "last" : "washington" }
}

{
   "_id" : 2,
   "alias" : [ "My dearest friend" ],
   "mobile" : "222-222-2222",
   "name" : { "first" : "abigail", "last" : "adams" }
}

{ "_id" : 3,
  "alias" : [ "Amazing grace" ],
  "mobile" : "111-111-1111",
  "name" : { "first" : "grace", "last" : "hopper" } }
#修改
db.students.update( { _id: 1 }, { $rename: { "name.first": "name.fname" } } )
#結果

{
  "_id" : 1,
  "alias" : [ "The American Cincinnatus", "The American Fabius" ],
  "mobile" : "555-555-5555",
  "name" : { "fname" : "george", "last" : "washington" }
}

註釋：

×重新命名不存在的欄位
重新命名欄位並且現有欄位名稱引用不存在的欄位時，$rename操作員不執行任何操作