Good day all,
I am trying to filter todays result in SQL table to a collection in powerapps. The column "dt" represents the column in sql of datetime type.
This is my powerapps filter:
ClearCollect(myCollectionName, Filter(myDatasource, Text(dt,"dd/mm/yyyy") = Text(Now(),"dd/mm/yyyy" )));
Seems like the collection is still empty even there is data for today in sql. May I know if my approach is the correct way in filtering?
Short answer: the data is likely being changed based on the client time zone. To fix it, you can update it by applying the time zone offset to the data from the SQL table, something along the lines of:
ClearCollect(
myCollectionName,
Filter(
myDatasource,
Text(DateAdd(dt, TimeZoneOffset(dt), Minutes), "dd/mm/yyyy") =
Text(Now(), "dd/mm/yyyy")))
Long(er) answer: the datetime type in SQL Server represents an absolute value of date and time. For example, the value '2021-12-23 09:30:00' represents 9:30 in the morning of the 23rd day of December, 2021 - at any part of the world. The date/time type in Power Apps, however, represents a point in time, typically referring to the local time where the app is being executed (or created). For example, if I selected that value and I'm in the US Pacific Time Zone (UTC-08:00), that would represent the same value as if someone in London (UTC+00:00) selected 2021-12-23 17:30:00. Since the two types represent different concepts, we may have mismatches like you are facing. To fix this, we can either use a type in SQL Server that has the same semantics as Power Apps (for example, 'datetimeoffset'), or adjust the time when it is being transferred between SQL and Power Apps.
The blog post at https://powerapps.microsoft.com/en-us/blog/working-with-datetime-values-in-sql explains in more details how to work with date/time values in SQL and Power Apps.
Related
I need to create an attendence list showing days in rows and employee names in colums. The list will always cover one full month chosen in parameters.
How can I create a recordset of days of chosen month? I've done it in command section but, due to ERP system limitations, it must done otherways.
Thank you,
Przemek
A good approach is to create a Calendar table (aka Date Dimension in data warehousing lingo). It makes it easy to show days without any attendance. If you don't need that aspect, you can simply create a formula that returns the attendance date month's day, and Group on that formula. The Day() function gets you the day of month. For example,
Day ({Orders.Order Date})
If you search 'creating a data dimension or calendar table' you'll find many helpful sources such as this one: https://www.mssqltips.com/sqlservertip/4054/creating-a-date-dimension-or-calendar-table-in-sql-server/
For your case, I agree with the comments in that post about using date instead of integer as the primary key. Integer PK makes more sense for true data warehousing scenarios as opposed to legacy databases.
CURRENT SITUATION:
I have a table of wildfire incidents with a timestamp with time zone (timestamptz) field to track when the observation occurred.
Everything in the data creation process is in UTC: the incoming data from the source, the app server that inserts the data, the insert python code (appends a "Z" to the time), and the database server are all in UTC.
The incidents' geographic extent spans several time zones in the US, Canada, and Mexico.
PROBLEM:
I've been querying on a day's worth of data in UTC time, but need to extract out data relative to local time. The midnight to midnight range will be different in each time zone.
My use case now is one day, but I was asked to consider arbitrary time ranges. E.g.: find all incidents in the hottest part of the day (say 10:00 to 18:00) local time.
This table is quite large and I have an index on the timestamptz field right now. Any changes I make will need to work with an index.
Account for daylight saving time.
I have a method to get the time zone for each record, so I don't need help with that.
I created a test table for this with a timestamptz field ts_with and a varchar field for the time zone tz. The following query returns what I want, so I feel like I'm making progress.
SELECT
name, test_tz.ts_with, test_tz.tz,
TIMEZONE(test_tz.tz, test_tz.ts_with) as timezone_with
FROM fire_info.test_tz
WHERE TIMEZONE(test_tz.tz, test_tz.ts_with) BETWEEN
'2018-08-07 00:00:00' AND '2018-08-07 23:59:59';
QUESTIONS:
Will this use my index? I'm thinking the timezone function will avoid it. Any solution for that? I'm considering adding another condition to the where clause that selects on timestamptz buffered by a day on either side. That would use the index and then the timezone function isn't sorting through too much data (~6k records per day during fire season). Would PG figure that out?
The timezone function is giving me DST offsets (e.g.: Denver is currently UTC-06). I assume I'll get standard time after DST ends. If I run a query in December for data in August, will it apply standard time or DST?
thanks!!!
The way you wrote the query, it cannot use an index on ts_with.
To use an index, the condition would have to be of the form ts_with <operator> <constant>, and there is no way to rewrite the query in that fashion.
So you should create a second index on timezone(test_tz.tz, test_tz.ts_with).
Let's say I have a date dimension and from my business requirements I know that the most granular I would need to go is to examine the specific day of the month that an event occurred.
The data I am given provides me with the exact time that an event occurred (YYYY-MM-DD HH:MM:SS). I have two opitons:
Before loading the data into the date dimension, slice the HH:MM:SS from the date.
Create the time attributes in my date dimension and insert the full date time.
The way I see it, I should go with the option 1. This would remove redundant data and save some space. However, if I go with option 2, should the business requirements ever change or if my manager suddenly wants to be more granular I wouldn't need to modify my original design. Which option is more commonly used? Are there more options that I did not consider?
Update - follow up question
I receive new data every month. If I used a pre built date dimension with all the dates would I then need to run my script every month to populate the table with new dates of that month or would I have a continuous process where by every day insert into the table one row, which would be that date?
I would agree with you and avoid option 2. A standard date dimension table is at the individual date level. If you did need to analyse by time of day, you could create an additional time of day dimension at the level of a second in a single day, and link to that from your fact table.
Your date dimension should be created by script automatically, rather than from the dates that events occurred. This allows you to analyse across a range of events from other facts, and on dates where no events occur, using a standard, prebuilt dimension.
I would also include the full date/time stamp as a column in the fact table, along with the 'DateKey' to the dimension table. This would allow you some visibility/analysis of the timestamp, you would not lose the data, and would still allow you to analyse by the date dimension.
Update - follow up question
Your pre-built date dimension (the standard way of doing it) would usually contain some dates in the future. There's no reason not to, for example, include another 5 years of dates in the table. But if you'd like it to gradually grow over time, you could have a script that is run once a day, once a month, or once a year to add new dates. Its totally up to you! There are many example scripts for building date dimensions- just google date dimension script. They exist for the language of your choice, e.g. SQL, C#, Power Query, etc.
I'm new to Neo4j so maybe I'm just completely wrong on this, but I'll give it a try!
Our data is mostly composed by reservations, users and facilities stored as nodes.
I need both to count the total reservations that occurred in a specific time frame and the overall income (stored as reservation.income) in this timeframe.
I was thinking to overcome the problem by creating the date as a node, in this way I can assign a relationship [:PURCHASED_ON] to all the reservations that occurred on a specific date.
As far as I've understood, creating the date as a node could give me a few pros:
I could split the date from dd/mm/yyyy and store them as integer properties, in this way I could use mathematical operators such as > and <
I could create a label for the node representing each month as a word
It should be easier to sum() the income on a day or a month
Basicly, I was thinking about doing something like this
CREATE (d:Day {name:01/11/2016 day: TOINT(01), month: TOINT(11), year: TOINT(2016)}
I have seen that a possible solution could be to create a node for every year, every month (1-12) and every day (1-31), but I think that would just complicate terribly the architecture of my Graph since every reservation has an "insert_date" (the day it's created) and then the official "reservation_date" (the day it's due).
Am I onto something here or is it just a waste of time? Thanks!
You may want to look at the GraphAware TimeTree library, as date handling is a complex thing, and this seems to be the logical conclusion of the direction you're going. The TimeTree also has support for finding events attached to your time tree between date ranges, at which point you can perform further operations (counting, summing of income, etc).
There are many date/time functions in the APOC plugin that you should take a look at.
As an example, you can use apoc.date.fields (incorrectly called by the obsolete name apoc.date.fieldsFormatted in the APOC doc) to get the year, month, day to put in your node:
WITH '01/11/2016' AS d
WITH apoc.date.fields(d, 'MM/dd/yyyy') AS f
CREATE (d:Day {name: d, day: f.days, month: f.month, year: f.years});
NOTE: The properties in the returned map have names that are oddly plural. I have submitted an issue requesting that the names be made singluar.
I need to get timestamps from Axapta-tables in TSQL, without timezone and / or daylight-bias-offsets for each time, eg from table JMGABSENCECALENDAR.
Taking this as initial approach, and regaring this, it works for current time. But reading data from the table referring to other timestamps, the solution provided in the second link doesn't get the information about daylight to the specified time.
For example:
I add an absence for today ( 2012-01-07 ).
Now, using SSMS, reading this dataset leads to
starttime = 2013-01-06 23:00:00.000
and endtime = 2013-01-07 23:00:00.000
That's ok, and I can use
DECLARE #UTCOffset SMALLINT
EXEC master..xp_regread
'HKEY_LOCAL_MACHINE',
'SYSTEM\CurrentControlSet\Control\TimeZoneInformation',
'ActiveTimeBias',
#UTCOffset OUTPUT
SELECT DATEADD(MINUTE, #UTCOffset, GETDATE()) AS UTCTime
to remove offset. This works fine on actual dates, but what's the right way to remove offset for past or future times, eg 2012-07-01 ?
Here, the offset is 120 minutes, because of summertime. Reading Reg-Value only returns current offset.
The task has to be solved in TSQL 2008.
I had a same problem, but it was in a complete different setting. I had nothing to do with axapta.
However, i had the problem that i had to know the UTC offset of different times. The tricky part here is the fact that different countries use a different approach towards daylight saving times, and therefor a difference in the offset may occur for different countries at the same time.
What i did was to create a lookup table where i put in the dates that UTC offsets change, these are known dates. I gave it an offset column so i could easily look up the offset that i needed for a certain date, using the between operator.
It worked for me, maybe this solution can provide you something?
Ps. You don't have to lookup the UTC date offset from out of the registry. Using the function getutcdate() will give you the same ;) Using that inside a DATADD makes it a little more readable ;)
Have fun and i hope i could contribute to your problem...
Just because the daylight savings switch dates change from year to year and state to state, your only viable option is a lookup table.
You can find the data for example here http://www.timeanddate.com/time/dst/2013a.html
However, you might not have to maintain that list yourself. timeanddate.com has a calculator on their site. Others offer similar services. You could look for a public API and then use a few lines of CLR code to call that API from your database.
Or you could use such a service to maintain your own copy of that data. Having your own lookup table will be by far the fastest solution.