couchdb get session date and query is on veiw - session

i want get the session date when it open to get all the record after i open my session not before ,i want something like this
function(doc) {
if (doc.created_at) {
if session.date => doc.created_at {
emit(doc.created_at, doc);
{
}
};


I've fallen for this problem myself when I was a couchdb newbie.
You need to understand first, that the map function is not executed when you run the view. The time of execution is only the very first time when the view is called after the document was last updated. And that only if the stale parameter was either not used or set to updateAfter.
What you can do instead is to use the startkey parameter when accessing the view. If you set this to the sessiondate, then only those documents created after the session date will be returned.
You however have to ensure consistent formatting and that the keys will be strictly sorted alphabetically numerically. E.g. by translating them to epoch times or a format in the style of yyyymmdd-ddmmss like 20140618-211259 for the time now (18th of June 2014 # 21:12:59)
Some examples of the parameters you can use are here.

Related

How to query between two datetimes using Laravel and Eloquent but but datetimes are not ordered? (error Prepared statement contains too many place...)

Background:
Data is retrieved every minute from an API and stored in a 'sensors' table.
If the data is older than one year. They will be summarized, saved as one new entry in the database and the old data will be deleted. Therefore the column 'date' is not sorted. An update to a specific date is not possible, since I cannot be sure whether the sensor actually generated data at that time.
Now to my problem:
I have a querie that looks something like this
private function getDataFromPeriod()
{
return Sensor::whereBetween('date', [$this->start, $this->end])->orderBy('date')->get();
}
Where $start and $end are in this format for example: '2022-12-31 01:59:59'.
This function is called during the function render() and that works (at the beginning the data from the last year are sorted)). However, when I call this function repeatedly in a different place, the error 1390 Prepared statement contains too many placeholders comes up.
I suspect this is because the query is not good.
Does anyone have an idea how I can improve the query or where else the error could be?
Thanks for your help

you don't need to sort by date;
just replace your code with this:
return Sensor::where('date','>=', $this->start)->where('date','<=', $this->end)->get();
this line will give you the sensors between your start and end date

Aerospike set expiration date for specific field

I have an Aerospike cache consists of list of data with value of json like structure.
example value: {"name": "John", "count": 10}
I was wandering if it is possible to set an expiration time for only the count field and reset it after some time.

Aerospike doesn't support such functionality out of the box. You would have to code this (hence your other post I guess:
Best way to update single field in Aerospike). You can add filters to only do this based on metadata of the record (the last update time of the record, accessible through Expressions) or any other logic and it should be super efficient and performant to then let a background ops query do the work.

Another approach can be adding your own custom expiration time stamp in your bin data like so:
{"name":"John", "count":10, "validTill":1672563600000000000}.
Here, I am using as below (you can use a different future timestamp format):
$ date --date="2023-01-01 09:00:00" +%s%N
1672563600000000000
Now when you read the record, read through an expression that returns count = 10 if your current clock is behind validTill, 0 otherwise. This can work if the count value on read is all you care about. Also, when you go to update the count value in a future write, you can use the same expression logic to update both count and validTill.
If this works for you, you don't have to scan and update records using background jobs.

Can I apply filter to data result of useStaticQuery in Gatsby.js

I am a beginner in Gatsby.js, I am developing a page with a dropdown of 12 months. Once user select the month, I will pass the value into a component, which will display different set of result based on month selected.
There is a graphql query to retrieve data by using useStaticQuery in my component.
I understand the useStaticQuery cannot accept any variable, so is it possible to filter the returned data and create another data set based on the month inputted? Or should I just create 12 components and display the correspondning one based on month selected?
(Actually I tried to loop the data and return a single aggregate value successfully, but I not sure if it is possible to return a subset of data result
data.allData.edges.forEach(edge => {
if(edge.node.month==inputMonth)
total=total+edge.node.amount
})
outValue= total
)

I think you are trying to use a find() loop. In your case:
let matchedMonth = data.allData.edges.find(edge => edge.node.month === inputMonth)
Basically, you are looping through allData (all months) to find which one is exactly equal to inputMonth. Since you are saving it in matchedMonth you can play whatever you want (passing to a component, etc).

CouchDB View with Multiple Parameters

I have a database that has an id column and a ts column. I need to be able to pass in the id and a start time and end time to retrieve all the values during the specified period. Can I do this with a view, or do I need the view to return all of the values that match the id? My concern is that I will be returning and parsing a lot more data than I really care about. Here is the format of my DB from my current view, which simply returns everything that matches the id...
{"id":"62db2aa3472dce80b1f2193fc21d52fd","key":"A-Meter-KW","value":{"_id":"62db2aa3472dce80b1f2193fc21d52fd","_rev":"1-6aadd58f4f5dabacf6f4f638396246d0","id":"A-Meter-KW","ts":1437969600000,"tz":"New_York","val":"191kW"}},
{"id":"62db2aa3472dce80b1f2193fc21d5100","key":"A-Meter-KW","value":{"_id":"62db2aa3472dce80b1f2193fc21d5100","_rev":"1-71155153c0f03c49b02850bee5535e22","id":"A-Meter-KW","ts":1437968700000,"tz":"New_York","val":"190kW"}},
{"id":"62db2aa3472dce80b1f2193fc21d45d7","key":"A-Meter-KW","value":{"_id":"62db2aa3472dce80b1f2193fc21d45d7","_rev":"1-661511616958d45fdff3307600d2a9ed","id":"A-Meter-KW","ts":1437967800000,"tz":"New_York","val":"189kW"}},
{"id":"62db2aa3472dce80b1f2193fc21d3c23","key":"A-Meter-KW","value":{"_id":"62db2aa3472dce80b1f2193fc21d3c23","_rev":"1-4e97cfc6cb97ddc65f04efd9043b3abd","id":"A-Meter-KW","ts":1437966900000,"tz":"New_York","val":"188kW"}},
{"id":"62db2aa3472dce80b1f2193fc21d2e35","key":"A-Meter-KW","value":{"_id":"62db2aa3472dce80b1f2193fc21d2e35","_rev":"1-120298e95c9d2b4b9cdf438836b6c0c0","id":"A-Meter-KW","ts":1437966000000,"tz":"New_York","val":"187kW"}},
{"id":"62db2aa3472dce80b1f2193fc21d22b0","key":"A-Meter-KW","value":{"_id":"62db2aa3472dce80b1f2193fc21d22b0","_rev":"1-61e55d02bd8f0c601274b904f46c9f34","id":"A-Meter-KW","ts":1437965100000,"tz":"New_York","val":"186kW"}},
{"id":"62db2aa3472dce80b1f2193fc21d1ce2","key":"A-Meter-KW","value":{"_id":"62db2aa3472dce80b1f2193fc21d1ce2","_rev":"1-b4fe80563c70a40981e293af9c6a87b3","id":"A-Meter-KW","ts":1437964200000,"tz":"New_York","val":"185kW"}},
{"id":"62db2aa3472dce80b1f2193fc21d1ccc","key":"A-Meter-KW","value":{"_id":"62db2aa3472dce80b1f2193fc21d1ccc","_rev":"1-bdf1881c4270e68e7a7ed90a1d945228","id":"A-Meter-KW","ts":1437963300000,"tz":"New_York","val":"184kW"}},
{"id":"62db2aa3472dce80b1f2193fc21d1303","key":"A-Meter-KW","value":{"_id":"62db2aa3472dce80b1f2193fc21d1303","_rev":"1-404d5934fc882aa36e6d355d9a3485ae","id":"A-Meter-KW","ts":1437962400000,"tz":"New_York","val":"183kW"}},
{"id":"62db2aa3472dce80b1f2193fc21d0941","key":"A-Meter-KW","value":{"_id":"62db2aa3472dce80b1f2193fc21d0941","_rev":"1-64288d1c98e9b93aa6c546acb1e02078","id":"A-Meter-KW","ts":1437961500000,"tz":"New_York","val":"182kW"}}
...
... my current query is http://localhost:5984/hist/_design/hist/_view/byId?key=%22A-Meter-KW%22&descending=true. I'd like to passing a start and end time as well, something like http://localhost:5984/hist/_design/hist/_view/byId?key=%22A-Meter-KW%22&descending=true&start=1437963300000&end=1437966000000 but cannot figure out how to do this.

EDITED:
In order for Couch to match your query all the data (eg:A-Meter-KW and date) must be in the key, emitted by the view. So I think you might do something like:
emit([key,year,month,day],doc._id)
Then you can use the parameters startkey and endkey to filter the results properly.
Reference: http://guide.couchdb.org/draft/views.html#many
Side consideration: I would not use an "id" property inside my documents, because it could get easily confused with the "_id" (compulsory) one.

Date Ranges in jqGrid Searches

We are using advanced search in the latest version of jqGrid, and our search dialog is configured to be always visible on the page above the grid. The structure of our data lists is dynamic. Thus, when we are going to display a list, we first do an ajax call to get the list of columns for the grid. We then construct the data model for the grid and make a request for the data.
Currently, in the request to get the columns, we return the data type of the column. If the data is a date, we display a date picker in the search form. However, some of our customers HATE having to use <= >= for date ranges. They want to be able to pick a date column and then set a start and end date using two side-by-side date pickers. I've been pushing them off for a while now because they have the ability to do date range searches, but the complaining isn't stopping. (It's more clicks to add the second filter with the end date)
Is there any way I can modify jqGrid to give me a date range control when I am configuring a search on a date column? I really don't want to have to set up an external search dialog UI just to deal with these complaints, but product-management is pushing really hard to get "normal" date ranges for the grids.

You can create your own custom search dialog. See this question which I asked couple days ago.
using setGridParam to change your postData array and include extra values in the filters JSON object that will be carried over to your server side where you can dissect it. In your case you can pass over your data range Start and End inside the filter item of the postData. Then reload your jqGrid like this
var $grid = $("#list');
//$grid.setGridParam({datatype:'json', page:1}).trigger('reloadGrid');
var post_data = {searchField:'',searchString:'', searchOper:'',
filters:'{"groupOp":"OR","rules":['+
'{"field":"Date","op":"ge","data":"2012-04-23"},'+
'{"field":"Date","op":"lt","data":"2012-04-25"}' +
']}'
};
$grid.setGridParam({postData:post_data}).trigger('reloadGrid');
The above will save the postData array with the new config and the reloadGrid sends a request to the server with the new postData array. This will preserve the paging as well; however, to get the old view of your grid (without search terms) you need to implement the reset button separately too and trigger reloadGrid after that for this to take effect.
Not sure if you have solved your problem by now; however, I am putting this solution here for any one from the future who has the same issue.

As far I know there is no way to do this, but to write it yourself.
http://www.trirand.com/jqgridwiki/doku.php?id=wiki:custom_searching
Filter jqGrid Data by Date Range?

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