mongodb get max value up to a number

Question

Suppose I have the following documents:

{
"name":"Matheus",
"age: 29"
},
{
"name":"Nicolas",
"age: 28"
},
{
"name":"Raphael",
"age: 26"
},
{
"name":"Trump",
"age: 48"
},
{
"name":"Elon Musk",
"age: 35"
}

Now, suppose I want to retrieve the document with the greatest age, but up to a given age, like this: return document with the greatest age up to 36, this should return

"name":"Elon Musk",
"age: 35"
}

Note that the less or equal operator wouldn't work, because I don't need the greatest of all, I need the greatest up to a certain number. I've learned here that I can acomplish almost what I want by doing

db.collection.find().sort({age:-1}).limit(1) // for MAX

but I don't need the global max, just the max inside a given bound. How can I acomplish this?

Are you looking for some data within a range say age between 30 to 36 — Clement Amarnath, Jul 23 '16 at 01:28
@ClementAmarnath the max of the set from [-a, 36] where a is any positive real number — Gatonito, Jul 23 '16 at 01:40

Siva Kumar · Answer 1 · 2016-07-23T02:11:49.023

1

db.collection.find({age:{$lte:36, $gte:20}}).sort({age:-1}).limit(1)

edited Jul 23 '16 at 02:11

answered Jul 23 '16 at 01:41

Siva Kumar

164
1
2
9

In this query we have the upper limit as 36, but we dont have the lower limit – Clement Amarnath Jul 23 '16 at 02:08
Updated the query, need to apply both $lte and $gte – Siva Kumar Jul 23 '16 at 02:12
Now it is exactly same as my answer, other than that I have not added sort and limit on the records. – Clement Amarnath Jul 23 '16 at 02:43

score 0 · Answer 2 · answered Dec 09 '19 at 10:38

0

Just pass the filter condition on the find and the it will retrieve the local maximum. db.collection.find({age: {$lt:36}}).sort({age:-1}).limit(1).

answered Dec 09 '19 at 10:38

Shibasis Patel

315
2
14

score -1 · Accepted Answer · answered Jul 23 '16 at 01:41

If you are looking for a query which performs operation on a range, then this would help

Let us have a collection named stackoverflow with below records

db.stackoverflow.find();
{ "_id" : ObjectId("5792c958caada3861f12e724"), "name" : "Matheus", "age" : 29 }
{ "_id" : ObjectId("5792c958caada3861f12e725"), "name" : "Nicolas", "age" : 28 }
{ "_id" : ObjectId("5792c958caada3861f12e726"), "name" : "Raphael", "age" : 26 }
{ "_id" : ObjectId("5792c958caada3861f12e727"), "name" : "Trump", "age" : 48 }
{ "_id" : ObjectId("5792c95acaada3861f12e728"), "name" : "Elon Musk", "age" : 35 }

the max of the set from [-a, 36] where a is any positive real number

Now let us assume a=28, then the query to retrieve records which are having age greater than 28 and less than 36 is shown below

db.stackoverflow.find({age:{$gt: 28, $lt:36}});

and execution of this query would show the below result

{ "_id" : ObjectId("5792c958caada3861f12e724"), "name" : "Matheus", "age" : 29 }
{ "_id" : ObjectId("5792c95acaada3861f12e728"), "name" : "Elon Musk", "age" : 35 }

mongodb get max value up to a number

3 Answers3