How to $sum by index of sub-array
the code did not work.
db.getCollection("test").aggregate([
{ $unwind: "$asks" },
{
$groups: {
_id: 0,
total: { $sum: { $arrayElemAt: ["$asks", 1] } },
count: { $sum: 1 },
},
},
]);
Thank you so much
There is a typo in your code. Change $groups to $group
Convert the string value to a double value and then calculate sum
Based on your image, you should use index 0, not index 1
Test Here
db.collection.aggregate([
{
$unwind: "$asks"
},
{
$group: {
_id: 0,
total: {
$sum: {
"$toDouble": {
"$arrayElemAt": [ "$asks", 0 ]
}
},
},
},
}
])
Related
I need help to count the elements of an array when it is in another array.
My command, when I tried to select the second array is,
db.artysci.aggregate([
{
$project: {
_id:0,
nazwa: 1,
nazwisko: 1,
numberOfSongs: { "album": {$size: "$utwor"}}
}
}
] )
Grid:
db.artysci.insert({
imie: 'Laurie',
nazwisko: 'Adkins',
rok_debiutu: 2006,
kraj_pochodzenia: ['Wielka Brytania'],
gatunek: 'neo soul',
album: [{
tytul:"19",
rok_edycji:2007,
gatunek: 'pop',
typ_nosnika: 'CD',
utwor: [{
numer: 1,
tytul_utworu: 'Daydreamer',
dlugosc_trwania: 3.41
},
{
numer: 2,
tytul_utworu: 'Best for Last',
dlugosc_trwania: 4.19
},
{
numer: 3,
tytul_utworu: 'Chasing Pavements',
dlugosc_trwania: 3.31
}
]
}]
})
Output when counting by $size:"$album",
{
"nazwisko" : "Adkins",
"numberOfSongs" : {
"album" : NumberInt(3)
}
}
How can I count elements of an array in an array by $size?
You can achieve this using Map and then summing it up. It works..
db.artysci.aggregate({
"$project": {
_id: 0,
nazwa: 1,
nazwisko: 1,
"numberOfAlbums": { "$size": { $ifNull: ["$album", []] } },
"numberOfSongs": {
"$sum": {
"$map": {
"input": "$album",
"in": { "$size": { $ifNull: ["$$this.utwor", []] } }
}
}
}
}
})
#Kacper,
Here is the soultion for your second question.
Yes, you can achieve it in either way, using the above method or using unwind and do the average..
Lets see an example using unwind:
Without divide/second:
db.notifications.aggregate([
{ $unwind: "$album" },
{ $unwind: "$album.utwor" },
{
$group: {
_id: "$_id",
avgDuration: { $avg: "$album.utwor.dlugosc_trwania" }
}
},
]);
With divide/second:
db.notifications.aggregate([
{ $unwind: "$album" },
{ $unwind: "$album.utwor" },
{
$group: {
_id: "$_id",
avgDuration: { $avg: { $divide: ["$album.utwor.dlugosc_trwania", 60] } }
}
},
]);
You can use $unwind and $group to get the counts.
db.collection.aggregate([
{
$unwind: "$album"
},
{
$unwind: "$album.utwor"
},
{
$group: {
_id: 0,
total: {
$sum: 1
}
}
}
])
Play
If you need more information, add it to your question.
Hey i need to get the sum of all totalPrice group by days
I get this result
but i need to fetch all rest days of month even if it returns 0
i need solution
this is my code
Order.aggregate([
{ $project: { yearMonthDay: { $dateToString: { format: "%Y-%m-%d", date: '$created' }}, totalPrice:"$totalPrice" }},
{ $group: { _id: "$yearMonthDay", count: { $sum: 1 }, total: {"$sum": "$totalPrice"} }},
{ $sort: { _id: -1 } },
{ $group: { _id: null, stats: { $push: "$$ROOT" }}},
{
$project: {
results: {
$map: {
input:{ $range:[16,31] },
as: 'day',
in: {
$let: {
vars: {
dateIndex: {
"$indexOfArray": ["$stats._id", {$dateToString:{ date:{$dateFromParts:{'year':2020, 'month':5, 'day':"$$day"}}, format:'%Y-%m-%d'}}]
}
},
in: {
$cond: {
if: { $ne: ["$$dateIndex", -1] },
then: { $arrayElemAt: ["$stats", "$$dateIndex"] },
else: { _id: {$dateToString:{ date:{$dateFromParts:{'year':2020, 'month':5, 'day':"$$day"}}, format:'%Y-%m-%d'}, count: 0, total: 0 } }
}
}
}
}
}
}
}
},
{ $unwind: "$results" },
{ $replaceRoot: { newRoot: "$results"}}
]
This query should work for you.
db.collectionName.aggregate([
{ $project: { yearMonthDay: { $dateToString: { format: "%Y-%m-%d", date: '$created' }}, totalPrice:"$totalPrice" }},
{ $group: { _id: "$yearMonthDay", count: { $sum: 1 }, total: {"$sum": "$totalPrice"} }},
{ $sort: { _id: -1 } },
{ $group: { _id: null, stats: { $push: "$$ROOT" }},
{
$project: {
results: {
$map: {
input: ["2020-05-16","2020-05-15","2020-05-14","2020-05-13","2020-05-12"],
as: "date",
in: {
$let: {
vars: {
dateIndex: {
"$indexOfArray": ["$stats._id", "$$date"]
}
},
in: {
$cond: {
if: { $ne: ["$$dateIndex", -1] },
then: { $arrayElemAt: ["$stats", "$$dateIndex"] },
else: { _id: "$$date", count: 0, total: 0 }
}
}
}
}
}
}
}
},
{ $unwind: "$results" },
{ $replaceRoot: { newRoot: "$results"}}
])
The First 3 steps is same as yours.
{ $group: { _id: null, stats: { $push: "$$ROOT" }} will push previous stage results into an arrray stats which we will use for lookup in later stage.
In last stage, we will create possible date range and iterate over that.
for each key in range.
"$indexOfArray": ["$stats._id", "$$date"] will check if date is present in stats array or not
Then we will use that index to fetch value from stats array otherwise push default values.
As these results are still under results, we will unwind that array and move to root.
If you server version is above 3.6,
we can simplify date range creation part as well. let's initialize input arrays as days using $range.
input:{ $range:[16,31] },
as: 'day'
and modifiy dateIndex part like this
dateIndex: {
"$indexOfArray": ["$stats._id", {$dateToString:{ date:{$dateFromParts:{'year':2020, 'month':5, 'day':"$$day"}}, format:'%Y-%m-%d'}]
}
And change default value part as well similarly.
else: { _id: {$dateToString:{ date:{$dateFromParts:{'year':2020, 'month':5, 'day':"$$day"}}, format:'%Y-%m-%d'}}, count: 0, total: 0 }
Or alternatively, we can also use concat for generating keys
dateIndex: {
"$indexOfArray": ["$stats._id", {$concat:["2020-05","-", {$convert:{input:"$$day", to:"string"}}]}]
}
// And default value
else: { _id: {$concat:["2020-05","-", {$convert:{input:"$$day", to:"string"}}]}, count: 0, total: 0 }
Similarly, you can run another loop for months as well.
I have the following stage in my MongoDB aggregation pipeline that returns the qty and sum of sales, which works fine:
{
$lookup: {
from: 'sales',
let: { part: '$_id' },
pipeline: [
{ $match: { $and: [{ $expr: { $eq: ['$partner', '$$part'] } }] } },
{ $group: { _id: null, qty: { $sum: 1 }, soldFor: { $sum: '$soldFor' } } },
{ $project: { _id: 0, qty: 1, soldFor: 1 } }],
as: 'sales'}},
{ $unwind: { path: '$sales', preserveNullAndEmptyArrays: true } },
{ $project: { _id: 1, sales: 1 }
}
However, if there are no sales, then the $project projection returns an empty sales object, but what I'd really like is it to return a completed object, but with 0 - like this:
{
sales: {
qty: 0,
soldFor: 0
}
}
You can use $cond operator here
{
"$project": {
"_id": 1,
"sales": {
"$cond": [
{ "$eq": [{ "$size": "$sales" }, 0] },
{
"sales": {
"qty": 0,
"soldFor": 0
}
},
"$sales"
]
}
}
}
I want to query following entries that have lists of lists and get their lengths:
db.collection.aggregate([
{ $unwind: '$molecules' },
{ $group: {
_id: '$scene',
molecules: { $push: { $size: '$molecules.data' } },
} },
])
gives
{ _id: 7674, molecules: [ 2, 1 ] }
I need to calculate the percentage of finalized/total items. The problem I have is calculating how many fields in the array equal to 'finished'. With my current solution I get finished items correctly, but total items are the same number as finished.
This is what I'm doing:
Items.aggregate([
{
$match: {
status: {
$ne: ['cancelled','pending']
}
}
},
{
$group: {
_id: '$person',
items: {
$push: {
total: '$status',
finished: {
$cond: [
{
$eq: ['$status', 'finished']
},
'$status',
null
]
}
}
}
}
},
{
$unwind: '$items'
},
{
$match: {
'items.finished': {
$ne: null
},
}
},
{
$group: {
_id: '$_id',
success: {
$push : '$items.finished'
},
total: {
$push: '$items.total'
}
}
},
{
$project: {
successCount: {
$size: '$success'
},
totalCount: {
$size: '$total'
}
}
},
{
$project: {
successScore: {
$divide: [ "$successCount", "$totalCount"]
}
}
}
]);
I also tried simpler solution, but can't figure how to keep total count field in the loop after doing $unwind
Items.aggregate([
{
$group: {
_id: '$_id',
totalCount: {$sum: 1},
finished: { $cond : [ {$eg: ['status', 'finished']}, $status, null] }
}
},
{ $unwind: '$finished'},
...
Then I can't access totalCount later