I am creating a simple calendar with appointments.
I have documents with the date ranges example below.
{
"start_date" : "2020-02-06T19:58:25.430Z",
"end_date" : "2020-02-16T19:58:25.430Z"
},
{
"start_date" : "2020-02-17T19:58:25.430Z",
"end_date" : "2020-02-27T19:58:25.430Z"
},
{
"start_date" : "2020-03-21T19:58:25.430Z",
"end_date" : "2020-03-31T19:58:25.430Z"
},
If user entered start_date and end_date that has conflict on already created date range, system should prevent the user to insert new document.
How can I do it? can I use Moment JS?
You can create a unique compound index:
db.collection.createIndex({'start_date':1, 'end_date': 1}, {'unique': true})
Related
I want to create a scheduled job for patients in a hospital. The patients will be informed every month by their reg_date.
I'm using new Date().getDate() inside my scheduled Jobs to run at 8.00 AM in the morning to send SMS to my patients. Meanwhile, I had been using string format date to save reg_date in my mongoDB. Here is snippets of my mongoDB docs :
{
customer: "John",
reg_date: "2017-02-17T16:39:26.969Z"
}
I've ben surfing for solutions but it turns out nothing, so I decided to post myself. Here is what i am trying to do :
customer.find({"reg_date.getDate()" : new Date(2017, 03, 17).getDate()})
.then(function(data) {
for (var key in data.length) {
sendTheSMS(key[data]);
};
});
E.g: What I am doing is "I want to get every patient who register at 17th day of the month and send them a SMS".
Any help will be appreciated. :D
For this type of bit complex query you need to use aggregation method instead regular find method.
$project this will help you to project your fields, here we are creating a new temporary field day with only date of the reg_date. Then we query using the new field day and we get the result.
This temp field day will never added to your schema or model, it is just like temp view we are creating like in SQL.
Here i projected only customer and day but Please project all the fields necessary in the result.
function getCustomerList(day, callback){
customer.aggregate([
{
$project:{
"customer": "$customer", //repeat the same for all field you want in result
"reg_date": "$reg_date",
"day":{$dayOfMonth:"$reg_date"} //put day of month in 'day'
}
},
{
$match:{
"day": day //now match the day with the incoming day value
}
},
], function(err, result){
callback(err, result);
})
}
getCustomerList(17, function(err, result){ // call the function like this with date you want
// Process the err & result here
});
Result will be like this
[{
"_id" : ObjectId("571f2da8ca97eb10163e6e17"),
"customer" : "John",
"reg_date" : ISODate("2016-04-17T08:58:16.414Z"),
"day" : 17
},
{
"_id" : ObjectId("571f2da8ca97eb10163e6e17"),
"customer" : "Prasanth",
"reg_date" : ISODate("2016-04-17T08:58:16.414Z"),
"day" : 17
}]
Ignore the day field projected during your process...
With reg_date in string you can't query for day of month as it only works with ISODate. I suggest first you convert the string in reg_date in all your documents with a script.
Then the following query should work
customer.aggregate([
{
$project:{
"document": "$$ROOT", //to get the whole document
"day":{$dayOfMonth:"$date"} //put day of month in 'day'
}
},
{
$match:{
"day": 17 //match 17
}
},
], function(data) {
for (var key in data.length) {
sendTheSMS(key[data]);
};
})
Use greater than and less than
var previousDate =new Date(2017, 1, 16); //month starts with 0
var nextDate=new Date(2017, 1, 18);
customer.find({reg_date : { $gt:previousDate,$lt:nextDate}})
.then(function(data) {
for (var key in data.length) {
sendTheSMS(key[data]);
};
});
Since reg_date is stored as a string, and not a Date/ISODate, you're limited as to what kind of query you can run (so I concur with the comment in one of the other answers that you should consider converting them to proper ISODate).
Considering that you want to query a date string for entries with a particular day-of-month, you can use a regular expression query:
customer.find({ reg_date : /-17T/ })
Or, dynamically:
let today = new Date();
let dom = ('00' + today.getDate()).slice(-2); // zero-pad day of month
let re = new RegExp('-' + dom + 'T');
customer.find({ reg_date : re })
You should also read this regarding speed optimizations, but still, regex queries aren't very fast.
I am trying to count the number of models in a collection based on a property:
I have an upvote model, that has: post (objectId) and a few other properties.
First, is this good design? Posts could get many upvotes, so I didn’t want to store them in the Post model.
Regardless, I want to count the number of upvotes on posts with a specific property with the following and it’s not working. Any suggestions?
upvote.count({‘post.specialProperty’: mongoose.Types.ObjectId(“id”), function (err, count) {
console.log(count);
});
Post Schema Design
In regards to design. I would design the posts collection for documents to be structured as such:
{
"_id" : ObjectId(),
"proprerty1" : "some value",
"property2" : "some value",
"voteCount" : 1,
"votes": [
{
"voter": ObjectId()// voter Id,
other properties...
}
]
}
You will have an array that will hold objects that can contain info such as voter id and other properties.
Updating
When a posts is updated you could simply increment or decrement the voteCountaccordingly. You can increment by 1 like this:
db.posts.update(
{"_id" : postId},
{
$inc: { voteCount: 1},
$push : {
"votes" : {"voter":ObjectId, "otherproperty": "some value"}
}
}
)
The $inc modifier can be used to change the value for an existing key or to create a new key if it does not already exist. Its very useful for updating votes.
Totaling votes of particular Post Criteria
If you want to total the amount for posts fitting a certain criteria, you must use the Aggregation Framework.
You can get the total like this:
db.posts.aggregate(
[
{
$match : {property1: "some value"}
},
{
$group : {
_id : null,
totalNumberOfVotes : {$sum : "$voteCount" }
}
}
]
)
I am working on Node.js + mongodb application and my question related to design of my database and queries. Firstly, describe my db structure. I have in my database two collections users and values. Document in users collection looks like this:
{
"_id" : 31450861,
"first_name" : "Jon",
"last_name" : "Doe",
"sex" : 2,
"bdate" : ISODate("1981-08-01T21:00:00Z"),
"city" : {
"id" : 282,
"title" : "Minsk"
},
"country" : {
"id" : 3,
"title" : "Belarussia"
},
"photo_max" : "https://foto.ru/RnhOKp2YJE4.jpg",
"relation" : 4,
"interests" : "science",
"music" : "pop",
"lang" : "RU",
}
This collection filled with users data (language, birthday, etc).
Documents from collection values looks like this:
{
"_id" : ObjectId("548023e5c16f310c23b75075"),
"userId" : "31450861", //reference to _id in users collection
"group1" : {
"value1" : 13,
" value2" : 7,
" value3" : 3,
" value4" : 14,
" value5" : 17
},
"group2" : {
" value1" : 9,
" value2" : 6,
" value3" : 17,
" value4" : 12,
" value5" : 13
}
So I need to make search for users on this database with lots of parameters from this two collection (their values (from collection values), sex, city, language etc.). I didn’t embed document values into users because I do a lot queries separately on them (but may be it’s anyway wrong design I need help on this). In future there will be more collections with similar structure like values (or at least there will be reference to userId), which I’ll have to include in search query, and I’ll need agility to extend my query on more collections.
So I need to run complex query on this collections (I know there is no JOINs in mongodb, so I know I have to query twice or use mapreduce).
So far my thoughts on this issue (aren’t tested in code just thoughts).
I need to write search function which performs 2 queries (and more in future):
Find users with same values and getting their ids.
var values = db.collection('values');
var ids = values.find({ value1: 1, value2: 2, value3: 3 }, {userId: 1 } ) //then transform ids so it became array with userId
Then in this found set find users on some more parameters (sex, birthday, language, etc)
var users = db.collection('users');
users.find({ $and: [{ _id: { $in: ids } }, {sex: 2 }, {lang: “RU” } ] });
My questions are:
1. Is it normal approach or I’ll end up with very slow performance and mess in code when adding new collections and queries?
2. If is it normal, how to easily add one more query to one more collection?
Any help, any thoughts are welcome! Thanks in advance!
This is my code:
this.aggregate(
{
$match: {
measurer_code : parseInt(_measurer_code),
user_code :parseInt(_user_code),
time : {$gte : iDate, $lte : eDate}
}
},
{
$group:{
sum: {$sum: "$value"},
cant: {$sum: 1}
}
},cb);
The collection has the following structure:
user_code : Number,
measurer_code : Number,
value : Number,
time : Date
Returns undefined. But if i run only $match or only $group returns documents.
Someone can help me?
Thanks!
When you group you have to specify how you want to group the data.
If you want count and sum across all the documents, you have to add "_id":null or "_id":1 (any constant) in the $group document. If you want to group by field "foo" you have to add "_id":"$foo" to the document.
I have documents as the below in mongodb { "_id" : ObjectId("4f956dee76ddb26752026e8f"), "page" : "home", "visited" : ISOdate(23/02/2013) }, { "_id" : ObjectId("4f956dee76ddb26752026e8f"), "page" : "home", "visited" : ISOdate(24/02/2013) }, { "_id" : ObjectId("4f956dee76ddb26752026e8f"), "page" : "home", "visited" : ISOdate(24/02/2013) } , { "_id" : ObjectId("4f956dee76ddb26752026e8f"), "page" : "home", "visited" : ISOdate(25/02/2013) } I want to get the day along with the count in mongodb using nodejs. It should return: day: 23/02/2013, count:1 , day: 24/02/2013, count:2 ,day: 25/02/2013, count:1.the result should be sorted in day so 23rd is first 24th is second and 25th is third. There are lots of entries around 1 million .
Firstly you have duplicate ObjectIds in there so that is bad data.
Lastly you should be able to build a query using aggregates something like this: (assuming you are on mongodb 2.2 + ).
db.mytable.aggregate([ {$group : {_id:"$visited", total:{$sum:1}}}, {$sort:{visited:-1}}])
/**
* group by day
* #link https://gist.github.com/phnessu4/5636642
* #param query document {key1:123,key2:456}
*/
var count_by_day = function(query){
return db.action.group(
{
keyf: function(doc) {
var date = new Date(doc.time);
var dateKey = (date.getMonth()+1)+"/"+date.getDate()+"/"+date.getFullYear();
return {'date': dateKey};
},
cond:query,
initial: {count:0},
reduce: function(obj, prev) {
prev.count++;
}
});
}
count_by_day({this:'is',the:'query'})
try this. i'm not sure your condition detail . you need write the query by yourself.
hope this can help you.