Question

I have a mongo document like this
{
"_id" : "2213",
"userId" : "99872",
"enterpriseId" : 13,
"courses" : [
 {
  "stateName" : "test program345",
  "courseId" : "456",
  "courseName" : "testCourse",
  "duration" : 1,
  "lag" : 0,
  "courseType" : "3",
  "scheduledStartDate" : ISODate("2019-07-02T10:16:22.000+05:30"),
  "scheduledEndDate" : ISODate("2019-07-02T10:16:22.000+05:30"),
  "transitionType" : "onComplete"
 },
 {
  "stateName" : "test program3455",
  "courseId" : "4",
  "courseName" : "testCourse",
  "duration" : 1,
  "lag" : 0,
  "courseType" : "2",
  "transitionType" : "onComplete",
  "scheduledStartDate" : ISODate("2019-07-08T17:07:13.479+05:30"),
  "courseProgress" : 100
 }
],
"userStatus" : 1,
"modified" : ISODate("2019-07-02T10:16:22.634+05:30"),
"created" : ISODate("2019-07-02T10:16:22.634+05:30"),
"completionStatus" : "IP"
}

I want to Update only those document where courseId is 4 and courseProgress is not exits and completionStatus is not equal to F.

我已经进行了此查询，但是即使courseProgress位于数组的第二个索引上，仍会更新文档

db.table.update({
    'courses.courseId':'4',
    'completionStatus':{$ne:'F'},
    'courses':{$elemMatch:{'courseProgress':{$exists:false}}},
    'enterpriseId':13},
    {$set : {'courses.$.courseId' : '45','courses.$.courseName':'testCourse'}},{multi:true}
)

即使在数组的第二个索引上存在courseProgress，此查询仍会更新该字段。由于我是mongodb的新手，请帮助我解决这个问题。

Answer 1

$仅更新它在数组中匹配的第一个元素。要更新数组中所有匹配的元素，您需要使用$[]。

尝试一下：

db.table.update({
    'courses.courseId':'4',
    'completionStatus':{$ne:'F'},
    'courses':{$elemMatch:{'courseProgress':{$exists:false}}},
    'enterpriseId':13},
    {$set : {'courses.$[].courseId' : '45','courses.$[].courseName':'testCourse'}},{multi:true}
)

有关详细信息，请阅读$[] Mongo documentation

查询以更新mongodb中的数组元素

1 个答案: