For example, I need to query the last 6 months by the earliest instance for each day (and last day by earliest instances in each hours, and last day by minutes). I was thinking of using MongoDB and having a nested structure like
year:{ month:{ day: { hour: { minute: [array of seconds]
But to get the first instance I would have to sort the array which is costly. Is there an easier way?
Would be better just to have a date field.
And query to be something like:
find(date: {$gt : 'starting_date', $lt : 'ending_date'})
Related
So I have a mongoose collection. This collection have a day property in it.
So let's say I have 3 documents in it:
{day: "2017-07-16T17:00:00.000Z"}
{day: "2017-07-17T17:00:00.000Z"}
{day: "2017-07-18T17:00:00.000Z"}
Each date has hardcoded 17:00 time in it. Consider this as the start time.
So let's say currentDate is 2017.07.17 and it's 16h. I need to return document that has day that is 16th, because of the time.
Next one starts in an hour, and in an hour I should be returning the 17th.
I tried:
Table.find({ day: { $lt: Date.now() } })
But this, on the 18th, still returns 16th.
How do I write this query so it returns document that is currently 'active' ?
I want to query Mongo based on timestamp. Follwing is the field in mongo.
"timestamp" : "2016-03-07 11:33:48"
Books is the collection name and below is my query for time period of 1 minute:
db.Books.find({"timestamp":{$gte: ISODate("2016-03-07T11:33:48.000Z"), $lt: ISODate("2016-03-07T11:34:48.000Z")}})
Also is there any alternative like I don't have to give greater and lower limit on timestamp. But query based time interval mentioned. Something like, if present timestamp is TS = "2016-03-07T11:33:48.000Z" then query should be between TS and TS + 1 minute rather than explicitly mentioning timestamp. Something like adding 1 minute to present timestamp
db.Books.find({"timestamp":{$gte: "2016-03-07 11:33:48", $lt: "2016-03-07 11:34:48"}})
ISODate is not required here
I'm developing an app using a MongoDB database that needs to check for items enabled for today's particular weekday.
Items can be enabled for any individual days of the week. (eg: Monday and Wednesday, or Tuesday and Thursday and Saturday, every day, whatever)
I was going to do this:
var currentWeekDay = Math.pow(2,new Date().getDay());
Therefore
Sunday === 1
Monday === 2
Tuesday === 4
Wednesday === 8
...
Saturday === 64
An example item might be like this
{_id:'blah', weekDays:127}
Now I want to query all items that are enabled for today...
MongoDB has an operator $and, but that's only for logical operations.
It has $bitsAnySet, but it looks like it's only implemented in 3.16.
https://jira.mongodb.org/browse/SERVER-3518
I'm running MongoDB v2.6.10.
So I'm wondering how to come up with a sensible indexable query.
Maybe
{_id:'blah', w0:1, w1:1, w2:1, w3:1, w4:1, w5:1, w6:1} //every day
{_id:'blah', w0:1, w1:0, w2:0, w3:0, w4:0, w5:0, w6:1} //Sat and Sun
That would be easily indexable. Can anyone think of a more terse way of doing it?
One option would be storing days as an array of integers:
{ '_id' : '1' , 'weekDays' : [0,1,2,3,4] } // mon-fri
{ '_id' : '2' , 'weekDays' : [5,6] } // sat-sun
Then you could create a simple index on weekDays field:
db.collection.createIndex({ weekDays : 1 })
And querying would also be pretty simple:
db.collection.find({weekDays : 2}) // wed
if i want to find a document created on a specific Day, until now i used a range
from the first minute of the day, to the last minute of the day in seconds , sth like :
query":{"dtCreated":{"$gte":{"sec":1381356782,"usec":0},"$lt":{"sec":1389356782,"usec":0}}}
is is possible to to somehow find all documents where only the Day, Month and year equals "dtCreated" ?
in pseudocode like :
query:{"dtCreated":ISODate("2014-01-23")} <- i know that may not be a valid iso date
but what i want is to find all documents for one day without using lt and gt ?
Sry for bad english and for any hints thanks in advance!
You can do it with the aggregation framework using the date aggregation operators.
Assuming dtCreated is an ISODate field, you could try something like this:
query = [
{
'$project': {
'year': {'$year':'$dtCreated'},
'month': {'$month':'$dtCreated'},
'day':{'$dayOfMonth':'$dtCreated'}
}
},
{
'$match' : {'year':'2014', 'month':'1', day:'1'}
}
]
db.mycollection.aggregate(query)
Edit: as orid rightly remarks, though this is an answer to your question (query for date without using date range), it's not a good way to solve your problem. I would probably do it this way: a range greater than or equal to today, but less than tomorrow
db.foo.find({'dtCreated':{'$gte':ISODate("2014-01-23"), '$lt':ISODate("2014-01-24")}})
I'm looking to write a pretty straightforward aggregation query in MongoDB, but struggling with a certain part.
What I would like to do is pull the sum of all records within the last 7 days grouped by day. It's easy enough to define the date 7 days ago as UTC, but I'd like to do it programmatically so I don't need to work out the UTC date everytime. For instance instead of 1341964800 i'd like to specify something like date() - 7 days.
Here's the current aggregation function I have which works:
db.visits_calc.group(
{ key:{date:true},
cond:{date:{$gt:1341964800}},
reduce:function(obj,prev) {prev.csum += obj.total_imp},
initial:{csum:0}
});
Thanks in advance!
You can perform arithmetic on the milliseconds timestamp returned by Date.now() to find the appropriate timestamp for 7 days ago. You need to subtract the number of milliseconds in 7 days (1000ms/s, 60 s/min, 60min/hr, 24 hrs/dy, 7dys/wk).
var weekAgo = Date.now() - (1000*60*60*24*7);
db.visits_calc.group(
{ key:{date:true},
cond:{date:{$gt:weekAgo}},
reduce:function(obj,prev) {prev.csum += obj.total_imp},
initial:{csum:0}
});