Hello I am building a reservation app using database as couchDb. I have several reservation documents and each of them has roomId, start date and end date.
Now when user creates a meeting request with roomId, start date and end date, I need to search for overlaps time ranges between the start time and endtime in the existing reservations and create a reservations only when there is no conflict. Along with this I also need to check for roomid.
The requirement is similar to Determine Whether Two Date Ranges Overlap.
I had created a view on my couch db emitting three keys:
function (doc) {
if (doc.type == "reservation") {
emit([doc.roomid, doc.startTime, doc.endTime], doc);
}
}
I did try creating something like
?startkey=["1970-01-01T00:00:00Z", ""]&endkey=["\ufff0", "1971-01-01T00:00:00Z"]
However I am not really getting how to compound query the view to find range of date along with the roomid.
Any help would be appreciated.
You could use Cloudant Query and specify the (StartA <= EndB) and (EndA >= StartB) search condition that's outlined in the referenced answer.
Create an index
Send a POST request to the _index endpoint, passing the following JSON data structure as payload.
POST https://$USERNAME:$PASSWORD#$HOST/$DATABASE/_index HTTP/1.1
{
"index": {
"fields": [
{ "name":"startTime",
"type":"string"
},
{
"name":"endTime",
"type":"string"
},
{
"name":"roomid",
"type":"string"
}
]
},
"type": "text"
}
Query the index
Send a POST request to the _find endpoint, passing the following JSON data structure as payload.
POST https://$USERNAME:$PASSWORD#$HOST/$DATABASE/_find HTTP/1.1
{
"selector": {
"startTime": {
"$lte": "2017-03-06T15:00:00Z"
},
"endTime": {
"$gte": "2017-03-06T14:00:00Z"
},
"roomid": {
"$eq": "room 123"
}
}
}
Replace the timestamp and room identifier values as needed. If the query returns at least one document you've encountered a booking conflict.
Related
On a daily basis, I'm pushing data (time_series) to Elasticsearch. I created an index pattern, and my index have the name: myindex_* , where * is today date (an index pattern has been setup). Thus after a week, I have: myindex_2022-06-20, myindex_2022-06-21... myindex_2022-06-27.
Let's assume my index is indexing products' prices. Thus inside each myindex_*, I have got:
myindex_2022-06-26 is including many products prices like this:
{
"reference_code": "123456789",
"price": 10.00
},
...
myindex_2022-06-27:
{
"reference_code": "123456789",
"price": 12.00
},
I'm using this query to get the reference code and the corresponding prices. And it works great.
const data = await elasticClient.search({
index: myindex_2022-06-27,
body: {
query: {
match: {
"reference_code": "123456789"
}
}
}
});
But, I would like to have a query that if in the index of the date 2022-06-27, there is no data, then it checks, in the previous index 2022-06-26, and so on (until e.g. 10x).
Not sure, but it seems it's doing this when I replace myindex_2022-06-27 by myindex_* (not sure it's the default behaviour).
The issue is that when I'm using this way, I got prices from other index but it seems to use the oldest one. I would like to get the newest one instead, thus the opposite way.
How should I proceed?
If you query with index wildcard, it should return a list of documents, where every document will include some meta fields as _index and _id.
You can sort by _index, to make elastic search return the latest document at position [0] in your list.
const data = await elasticClient.search({
index: myindex_2022-*,
body: {
query: {
match: {
"reference_code": "123456789"
}
}
sort : { "_index" : "desc" },
}
});
Let's say I have documents like so:
{
_id: "a98798978s978dd98d",
type: "signature",
uid: "u12345",
category: "cat_1",
timestamp: UNIX_TIMESTAMP
}
My goal is to be able to count all signature's created by a certain uid but being able to filter by timestamp
Thanks to Alexis, I've gotten to this far with a reduce _count function:
function (doc) {
if (doc.type === "signature") {
emit([doc.uid, doc.timestamp], 1);
}
}
With the following queries:
start_key=[null,lowerTimestamp]
end_key=[{},higherTimestamp]
reduce=true
group_level=1
Response:
{
"rows": [
{
"key": [ "u11111" ],
"value": 3
},
{
"key": [ "u12345" ],
"value": 26
}
]
}
It counts the uid correctly but the filter doesn't work properly. At first I thought it might be a CouchDB 2.2 bug, but I tried on Cloudant and I got the same response.
Does anyone have any ideas on how I could get this to work with being ale to filter timestamps?
When using compound keys in MapReduce (i.e. the key is an array of things), you cannot query a range of keys with a "leading" array element missing. i.e. you can query a range of uuids and get the results ordered by timestamp, but your use-case is the other way round - you want to query uuids by time.
I'd be tempted to put time first in the array, but unix timestamps are not so good for grouping ;). I don't known the ins and outs of your application but if you were to index a date instead of a timestamp like so:
function (doc) {
if (doc.type === "signature") {
var date = new Date(doc.timestamp)
var datestr = date.toISOString().split('T')[0]
emit([datestr, doc.uuid], 1);
}
}
This would allow you to query a range of dates (to the resolution of a whole day):
?startkey=["2018-01-01"]&endkey=["2018-02-01"]&group_level=2
albeit with your uuids grouped by day.
I'm having a bit of an issue understanding how to query dates; I think the issue might be with how my data is structured. Here is a sample document on my database.
{
"phone_num": 12553,
"facilities": [
"flat-screen",
"parking"
],
"surroundings": [
"ping-pong",
"pool"
],
"rooms": [
{
"room_name": "Standard Suite",
"capacity": 2,
"bed_num": 1,
"price": 50,
"floor": 1,
"reservations": [
{
"checkIn": {
"$date": "2019-01-10T23:23:50.000Z"
},
"checkOut": {
"$date": "2019-01-20T23:23:50.000Z"
}
}
]
}
]
}
I'm trying to query the dates to see check if a specific room is available at a certain date-range but no matter what I do I can't seem to get a proper result, either my query 404's or returns empty array.
I really tried everything, right now for simplicity I'm just trying to get the query to work with checkIn so I can figure out what I'm doing wrong. I tried 100 variants of the code below but I couldn't get it to work at all.
.find({"rooms": { "reservations": { "checkIn" : {"$gte": { "$date": "2019-01-09T00:00:00.000Z"}}}}})
Am I misunderstanding how the .find method works or is something wrong with how I'm storing my dates? (I keep seeing people mentioning ISODates but not too sure what that is or how to implement).
Thanks in advance.
I think the query you posted is not correct. For example, if you want to query for the rooms with the checkin times in a certain range then the query should be like this -
.find({"rooms.reservations.checkout":{$gte:new Date("2019-01-06T13:11:50+06:00"), $lt:new Date("2019-01-06T14:12:50+06:00")}})
Now you can do the same with the checkout time to get the proper filtering to find the rooms available within a date range.
A word of advice though, the way you've designed your collection is not sustainable in the long run. For example, the date query you're trying to run will give you the correct documents, but not the rooms inside each document that satisfy your date range. You'll have to do it yourself on the server side (assuming you're not using aggregation). This will block your server from handling other pending requests which is not desirable. I suggest you break the collection down and have rooms and reservations in separate collections for easier querying.
Recently I was working on date query. First of all we need to understand how we store date into the mongodb database. Say I have stored data using UTC time format like 2020-07-21T09:45:06.567Z.
and my json structure is
[
{
"dateOut": "2020-07-21T09:45:06.567Z",
"_id": "5f1416378210c50bddd093b9",
"customer": {
"isGold": true,
"_id": "5f0c1e0d1688c60b95360565",
"name": "pavel_1",
"phone": 123456789
},
"movie": {
"_id": "5f0e15412065a90fac22309a",
"title": "hello world",
"dailyRentalRate": 20
}
}
]
and I want to perform a query so that I can get all data only for this( 2020-07-21) date. So how can we perform that?. Now we need to understand the basic.
let result = await Rental.find({
dateOut: {
$lt:''+new Date('2020-07-22').toISOString(),
$gt:''+new Date('2020-07-21').toISOString()
}
})
We need to find 21 date's data so our query will be greater than 21 and less than 22 cause 2020-07-21T00:45:06.567Z , 2020-07-21T01:45:06.567Z .. ... .. this times are greater than 21 but less than 22.
var mydate1 = new Date();
var mydate1 = new Date().getTime();
ObjectId.getTimestamp()
Returns the timestamp portion of the ObjectId() as a Date.
Example
The following example calls the getTimestamp() method on an ObjectId():
ObjectId("507c7f79bcf86cd7994f6c0e").getTimestamp()
This will return the following output:
ISODate("2012-10-15T21:26:17Z")
If your using timestamps data to query.
EG : "createdAt" : "2021-07-12T16:06:34.949Z"
const start = req.params.id; //2021-07-12
const data = await Model.find({
"createdAt": {
'$gte': `${start}T00:00:00.000Z`,
'$lt': `${start}T23:59:59.999Z`
}
});
console.log(data);
it will show the data of particular date .i.,e in this case. "2021-07-12"
I'm trying to add (aka. push to existing array) in couchDB document.
Any feedback is greatly appreciated.
I have a document called "survey" inside my database called "database1".
I have "surveys" as a set of arrays which consists of objects that has information on each survey.
My goal is to update my "survey" document. Not replacing my array, but adding a new object to the existing array. I've used "nano-couchdb" and "node-couchdb", but could not find a way around it. I was able to update my "surveys", but it would replace the whole thing, not keeping the existing objects in array.
1) Using Nano-couchdb:
db.insert({ _id, name }, "survey", function (error, resp) {
if(!error) { console.log("it worked")
} else {
console.log("sad panda")}
})
2) Using couchdb-node:
couch.update("database1", {
_id: "survey",
_rev:"2-29b3a6b2c3a032ed7d02261d9913737f",
surveys: { _id: name name: name }
)
These work well with adding new documents to a database, but doesn't work with adding stuff to existing documents.
{
"_id": "survey",
"_rev": "2-29b3a6b2c3a032ed7d02261d9913737f",
"surveys": [
{
"_id": "1",
"name": "Chris"
},
{
"_id": "2",
"name": "Bob"
},
{
"_id": "1",
"name": "Nick"
}
]
}
I want my request to work as it would for
"surveys.push({_id:"4",name:"harris"})
whenever new data comes in to this document.
Your data model should be improved. In CouchDB it doesn't make much sense to create a huge "surveys" document, but instead store each survey as a separate document. If you need all surveys, just create a view for this. If you use CouchDB 2.0, you can also query for survey documents via Mango.
Your documents could look like this:
{
"_id": "survey.1",
"type": "survey",
"name": "Chris"
}
And your map function would look like that:
function (doc) {
if (doc.type === 'survey') emit(doc._id);
}
Assuming you saved this view as 'surveys' in the design doc '_design/documentLists', you can query it via http://localhost:5984/database1/_design/documentLists/_view/surveys.
Am new to nodejs here and I have below data in my session which will be available during page post
{"lstDetails":
[
{"ID":"FFSDER2da2411cDSs12CGh21",
"FirstName":"Test",
"LastName":"Data",
"DOB":"8/15/1921 12:00:00 AM",
"AddressLine1":"Test Address Line 1",
"AddressLine2":"",
"City":"FakeCity",
"State":"ST",
"Zip":"41511",
"PID":0,
"EmailID":"SC4239925#FakeEmail.com",
"Gender":"1",
"WorkPhone":"",
"OtherPhone":"5555555555",
"ICarier":
{"ICName":null,
"IGName":null,
"IGNum":null
}
},
{"ID":"DS24DASD5da21afd56D4#2!",
"FirstName":"Test2",
"LastName":"Data2",
"DOB":"8/15/1921 12:00:00 AM",
"AddressLine1":"Test2 Address Line 1",
"AddressLine2":"",
"City":"FakeCity2",
"State":"ST2",
"Zip":"41511",
"PID":0,
"EmailID":"SC4239925#FakeEmail.com",
"Gender":"1",
"WorkPhone":"",
"OtherPhone":"5555555555",
"ICarier":
{"ICName":null,
"IGName":null,
"IGNum":null
}
}
]
}
and the above detail will be stored in req.Session. How can search for particular data from above session object using ID and fetch a particular record? I have went on through net, but unfortunately did not find any useful information.
You can use either filter or map to search through the array to find the object (node) you want.
Simplified example:
var myArray = [{
"ID":"FFSDER2da2411cDSs12CGh21",
"FirstName":"Test",
"LastName":"Data"
},
{
"ID":"DS24DASD5da21afd56D4#2!",
"FirstName":"Test2",
"LastName":"Data2"
}];
var result = myArray.filter(function(f) {
if (f.ID === 'FFSDER2da2411cDSs12CGh21') {
return f;
}
});
Results in a result array with one object, filtered on ID. You can filter by comparing on part of string, RegEx, etc.