I currently have an academic year start date and end date. I want to get student data for every week during this academic year. Currently i have created an array which contains all the start and end dates of every week and i am looping through each week and calling the db each time like this:
let allWeeksData = []
let groupQuery: any = {
_id: {
attendance_code: "$attendance_code",
},
total: { $sum: 1 },
};
for(let dateRanges of dateRangesArray)
{
const startDate = dateRanges.start_date;
const endDate = dateRanges.end_date;
const rawResults = await sessionAttendanceModel.aggregate([
{
$match: {
student_school: { $in: studentSchoolIDs },
"date.date": {
$gte: new Date(startDate),
$lte: new Date(endDate),
},
attendance_code: {
$in: usedAttendanceCodes,
},
},
},
{
$group: groupQuery,
},
]);
rawResults.start_date = startDate
rawResults.end_date = endDate
allWeeksData.push(rawResults)
}
However this is quite slow. Is there a way to call the db only once using an aggregate group and get the same end result?
You can $group everything by weeks and then in $project pipeline you can formulate exit values by your needs
Your aggregation would have something like this
[{
$group:{
_id:{
$week: "$date.date"
},
data:{
$first: "$$ROOT"
}
}
}]
Maybe group by this:
{
_id: {
attendance_code: "$attendance_code",
date: {
$dateTrunc: {
date: "$date.date",
unit: "week",
startOfWeek: "monday"
}
},
},
total: { $sum: 1 },
}