db.collection.aggregate(
[
{ $group: { _id: null, count: { $sum: 1 } } }
]
)
Suppose the output of count is 20. i want to multiply this count value (20) with 5. result should be 100 in another row total : count*5.
Related
I have a find statement in a store database that looks like this:
db.Purchases.find( {}, { store: 1, total: 1, _id: 0 } ).sort( { "store" : 1} ) =
{ "store" : DBRef("Location", ObjectId("5dae22702486f7d89ba7633c")), "total" : "$1500" }
{ "store" : DBRef("Location", ObjectId("5dae227f2486f7d89ba7633d")), "total" : "$156.88" }
{ "store" : DBRef("Location", ObjectId("5dae22992486f7d89ba7633e")), "total" : "$1510" }
{ "store" : DBRef("Location", ObjectId("5dae22992486f7d89ba7633e")), "total" : "$3000" }
{ "store" : DBRef("Location", ObjectId("5dae22cd2486f7d89ba76340")), "total" : "$156.88" }
I need to sum the totals from output 3 and 4 (i.e $1510 and $3000) and display the result as one line in the output along all the other outputs. How do I do this?
Try this:
db.Purchases.aggregate(
[
{
$group:
{
_id: "$store",
totalAmount: { $sum: "$total"}
}
}
]
)
Observation: total must be a numeric type in MongoDB.
How to find duplicate records count in mongodb
Here is how I get that in mysql
SELECT name, COUNT(*) c FROM table GROUP BY name HAVING c > 1;
Try this
db.table.group({
"key": {
"name": true
},
"initial": {
"c": 0
},
"reduce": function(obj, prev) {
if (true != null) if (true instanceof Array) prev.c += true.length;
else prev.c++;
}});
db.mycollection.aggregate(
// Pipeline
[
// Stage 1
{
$group: {
"_id": "$a",
count: {
$sum: 1
}
}
},
// Stage 2
{
$match: {
count: {
$gt: 1
}
}
},
]
);
Realise this topic has been asked many times - but the advice hasn't helped me solve this problem.
The following query is trying to determine the presence of sales on a given weekday using ISODay. Because the query will be run at the start of the month, I need to know how many occurrences of the specific ISOday occur in the month.
var query = { eventType: 'Sale', site : 4, tank: 1, txnDate : { "$gt" : new Date('2018-08-01T00:00:00') } };
db.tankevent.aggregate([
{ $match: query },
{ $project : {
isoDay: { $isoDayOfWeek: "$txnDate" },
dayDate: { $dateToString: { format: "%d", date:"$txnDate" } }
}
},
{ $group:
{ _id : { isoday: "$isoDay", dday: "$dayDate" }, count: { "$sum" : 1 } }
},
{ $sort: { "_id.isoday": 1, "_id.dday": 1 } }
])
provides the following output
/* 1 */
{
"_id" : {
"isoday" : 1,
"dday" : "06"
},
"count" : 62.0
}
/* 2 */
{
"_id" : {
"isoday" : 1,
"dday" : "13"
},
"count" : 69.0
}
/* 3 */
{
"_id" : {
"isoday" : 1,
"dday" : "20"
},
"count" : 72.0
}
/* 4 */
{
"_id" : {
"isoday" : 2,
"dday" : "07"
},
"count" : 75.0
}
I am trying to have "count" represent the number of unique "dday" records - so using the output above, I want count to be "3" for isoDay = 1. At the moment count is reporting number of sales events that occurred for the group combination
All you need to do is have the grouping twice.
db.tankevent.aggregate([
{ $match: query },
{ $project : {
isoDay: { $isoDayOfWeek: "$txnDate" },
dayDate: { $dateToString: { format: "%d", date:"$txnDate" } }
}
},
{ $group:
{ _id : { isoday: "$isoDay", dday: "$dayDate" }, count: { "$sum" : 1 } }
},
{ $project : {
isoDay_Final: "$_id.isoday"
}
},
{ $group:
{ _id : "$isoDay_Final", count: { "$sum" : 1 } }
},
{ $sort: { "_id": 1 } }
])
imagine you have website where people post their ads. So, each ad has some selected properties, for example cars has different engine types, gears, colors and etc. Those properties user selects before submiting a listing.
I store selected properties in a jsonb format in listings table, look at the data column:
.
So, each listing contains data like this:
{
"properties":[
{
"id":"1",
"value_id":"1"
},
{
"id":"2",
"value_id":"5"
},
{
"id":"3",
"value_id":"9"
},
{
"id":"4",
"value":"2.0"
},
{
"id":"7",
"value":"2017"
},
{
"id":"6",
"value":"180.000"
}
]
}
Now, the question is:
1) How to filter listings by those id's and value's which are in json? For example, show listings where id = 2 and it's value = 5 AND id = 3 and it's value = 9 and so on. I dont need OR, i need AND. So, filter data by multiple id's and value's.
2) First point + ability to compare id's and value's (greater or lower than).
answering first point, it's probably the first time when I find use for jsonb[]:
t=# with c(a,j) as (values(18,'{
"properties":[
{
"id":"1",
"value_id":"1"
},
{
"id":"2",
"value_id":"5"
},
{
"id":"3",
"value_id":"9"
},
{
"id":"4",
"value":"2.0"
},
{
"id":"7",
"value":"2017"
},
{
"id":"6",
"value":"180.000"
}
]
}'::jsonb), (19,'{"properties":[{"id": "1", "value_id": "1"}]}'))
, m as (select a, array_agg(jb.value)::jsonb[] ar from c, jsonb_array_elements(j->'properties') jb group by a)
select a
from m
where '{"id": "1", "value_id": "1"}'::jsonb = any(ar)
and '{"id": "3", "value_id": "9"}'::jsonb = any(ar);
a
----
18
(1 row)
and for the second requirement - it won't be that short, as you need to compare (and thus parse json):
t=# with c(a,j) as (values(18,'{
"properties":[
{
"id":"1",
"value_id":"1"
},
{
"id":"2",
"value_id":"5"
},
{
"id":"3",
"value_id":"9"
},
{
"id":"4",
"value":"2.0"
},
{
"id":"7",
"value":"2017"
},
{
"id":"6",
"value":"180.000"
}
]
}'::jsonb), (19,'{"properties":[{"id": "1", "value_id": "1"}]}'))
, m as (select a, jb.value->>'id' id,jb.value->>'value_id' value_id from c, jsonb_array_elements(j->'properties') jb)
, n as (select m.*, count(1) over (partition by m.a)
from m
join c on c.a = m.a and ((id::int >= 1 and value_id::int <2) or (id::int >2 and value_id::int <= 9)))
select distinct a from n
where count > 1;
a
----
18
(1 row)
with basic idea to use OR to get possible rows and then check if ALL of OR conditions were met
I wonder how we can do the below translation from sql to mongoDB:
Assume the table has below structure:
table
=====
-----
##id contribution time
1 300 Jan 2, 1990
2 1000 March 3, 1991
And I want to find a ranking list of ids in the descending orders of their number of contributions.
'$' This is what I do using sql:
select id, count(*) c from table group by id order by c desc;
How can I translate this complex sql into mongoDB using count(), order() and group()?
Thank you very much!
Setting up test data with:
db.donors.insert({donorID:1,contribution:300,date:ISODate('1990-01-02')})
db.donors.insert({donorID:2,contribution:1000,date:ISODate('1991-03-03')})
db.donors.insert({donorID:1,contribution:900,date:ISODate('1992-01-02')})
You can use the new Aggregation Framework in MongoDB 2.2:
db.donors.aggregate(
{ $group: {
_id: "$donorID",
total: { $sum: "$contribution" },
donations: { $sum: 1 }
}},
{ $sort: {
donations: -1
}}
)
To produce the desired result:
{
"result" : [
{
"_id" : 1,
"total" : 1200,
"donations" : 2
},
{
"_id" : 2,
"total" : 1000,
"donations" : 1
}
],
"ok" : 1
}
Check the mongodb Aggregation
db.colection.group(
{key: { id:true},
reduce: function(obj,prev) { prev.sum += 1; },
initial: { sum: 0 }
});
After you get the result, sort it by sum.