how to set particular field in array of object in mongodb aggregation or pipeline query along with conditional update of the other field in document?

Question

{
id:1,
projectName:'Project1'
start:"17-04-2022",
end:"12-05-2020",
tasks:[
{
taskId:1,
taskName:'first task',
taskStart:'20-04-2022',
taskEnd:'25-04-2022'
},

{
taskid:2,
taskName:'second task',
taskStart:'25-04-2022',
taskEnd:'30-04-2022'
},

]
},
{
id:2,
projectName:'Project2'
start:"27-04-2022",
end:"22-05-2020",
tasks:[
{
taskId:1,
taskName:'first task',
taskStart:'30-04-2022',
taskEnd:'12-05-2022'
},

{
taskid:2,
taskName:'second task',
taskStart:'28-04-2022',
taskEnd:'15-05-2022'
},

]
}

how to update field "taskEnd" of tasks array with document id=1 and taskID=1 AND while updating if data from the frontend which is used to update the "taskEnd" exceeds "end" field, update the "end" field also with same value.

Thanks in Advance,

I know how to update specific field for the array of objects and conditional update of field with two separate queries.

can it be done with single query?

You can do the same in single conditional update. Did you try? — Gibbs, Feb 05 '22 at 10:01

score 0 · Answer 1 · answered Feb 06 '22 at 05:46

You can do this with a pipeline update instead of using an update document. I'm assuming you are getting the input date in the same format as the other dates.

var input_date = "11-05-2020";
db.collection.update({
  id: 1
},
[
  {
    $addFields: {
      end: {
        $cond: [
          {
            $gt: [
              {
                $dateFromString: {
                  dateString: "$end"
                }
              },
              {
                $dateFromString: {
                  dateString: input_date 
                }
              }
            ]
          },
          "$end",
          input_date 
        ]
      },
      tasks: {
        $map: {
          input: "$tasks",
          as: "elem",
          in: {
            $cond: [
              {
                $eq: [
                  "$$elem.taskId",
                  1
                ]
              },
              {
                $setField: {
                  field: "taskEnd",
                  input: "$$elem",
                  value: input_date 
                }
              },
              "$$elem"
            ]
          }
        }
      }
    }
  }
])

how to set particular field in array of object in mongodb aggregation or pipeline query along with conditional update of the other field in document?

1 Answers1