MongoDB:如何更新数组中的嵌入文档

Question

我有以下文件:

{_id: '4eb79ee1e60fc603788e7259',
Name: 'name', 
Subsidiaries: [
  { _id: '4eb79eeae60fc603788e7271',
   Location: 'location1'},
  { _id: 'subid2',
   Location: 'location2'},
]}

我想更新子公司的位置:

db.Departments.update({ "_id" : ObjectId("4eb79ee1e60fc603788e7259"), "Subsidiaries._id" : ObjectId("4eb79eeae60fc603788e7271") }, { "$set" : { "Subsidiaries.Location" : "City" } })

但MongoDb返回错误:"无法使用字符串字段名称[Location]附加到数组

Answer 1

您必须使用$ poistional运算符来更新嵌入的文档,

db.Departments.update(
     { "_id" : ObjectId("4eb79ee1e60fc603788e7259"),
       "Subsidiaries._id" : ObjectId("4eb79eeae60fc603788e7271") },
     { "$set" : { "Subsidiaries.$.Location" : "City" } }
 )