如何在MongoDB中更新数组？

Question

I have about 40 documents in my collection. I need to update some elements in two arrays. The arrays of the document looks like

 "array1": [
    {
        "id" : "2030170",
        "date1" : ISODate("2016-01-04T07:10:00.000Z"),
        "date2" : ISODate("2016-01-04T08:00:00.000Z")
    }
 ],
 "array2": [
    {
        "Id" : "43463565",
        "date1" : ISODate("2016-01-04T07:10:00.000Z"),
        "date2" : ISODate("2016-01-04T08:00:00.000Z")
    }
  ]

How can I update fields date1 and date 2 in both arrays?

I am using java script for updating another data also. It looks like

db.getCollection('my.collec').update({ "myId" : { $gte: 293, $lte: 438}},
                                          {

                                          "$currentDate": { "time1": true },
                                          "$set": {
                                          "time2": true,
                                          "time3": true

                                          }
                                            },   { multi: true }
                                          )

I was trying this way:

  db.getCollection('my.collec').update({ "myId" : { $gte: 293, $lte: 438}},
                                              {

                                              "$currentDate": { "time1": true },
                                              "$set": {
                                              "time2": true,
                                              "time3": true,

                              "array1.0.date1": true,
                              "array1.0.date2": true,
                              "array2.0.date1": true,
                              "array2.0.date2": true
                                              }
                                                },   { multi: true }
                                              )

But instead of currentDate I get "true". With variables like time everything works fine.

Answer 1

I'm wondering why all the documents aren't in one array? In any event try:

db.YOURCOLLECTION.update(

{$and: [ 
    { date1: {$lt: $currentDate}}, 
    { date2: {$lt: $currentDate}}
    ] 
},

{
date1 : $currentDate,
date2 : $currentDate
},

{upsert: true}
)

Edit: one thing I noticed $currentDate I don't think converts to ISO automatically so you would need to either explicitly input the desired time stamp (per the gentleman above) replacing $currentDate with that value in ISO in the update expression above or use a conversion library.

See: https://docs.mongodb.org/manual/reference/operator/update/currentDate/

Answer 2

I need to update some elements in some arrays

Would be nice to know what the criteria is

How can I update fields date1 and date 2 in both arrays such that these fields will not be added to objects that do not have them?

Assuming that you are only updating array1 and array2 first element

db.josef.update({
    "array1": {
        $size: 1
    },
    "array2": {
        $size: 1
    }
},
{
    $set: {
        "array1.0.date1": ISODate("2011-01-01T00:00:00.0000Z"),
        "array1.0.date2": ISODate("2011-01-01T00:00:00.0000Z"),
        "array2.0.date1": ISODate("2011-01-01T00:00:00.0000Z"),
        "array2.0.date2": ISODate("2011-01-01T00:00:00.0000Z")
    }
},
{
    multi: true
})

How can I update fields date1 and date 2 in both arrays such that these fields will not be added to objects that do not have them?

upsert is false by default so it won't be added.