I am trying to build a reminder application using c# and, i want to employee the concept of repeat in my application [no repeat, daily, weekly ... ], but the problem i am facing is that how i shall store this reminder in the database.
I tried to duplicate the reminder and change it's date, but what if it has no end date then this one doesn't seem a very smart idea. And then i tried to keep one record in the database and when ever the date becomes past in case it's a repeated it modify the date to the next one, but here i facing the problem of how i search for reminders in a specific days. I wondered if there is a way that SQL can duplicate a record between two dates temporarily for the search.
So i am almost out of ideas right now, any help?!
I don't think you should change any data dynamically in the reminder records. You should add a variable called "remDayOfWeek" to the database -- this will be the day of the week that the user started if the user is to be reminded weekly. Let's say you scan once a day for users that need reminders. All users with daily reminders will need reminders. For users with weekly reminders, all those with "remDayOfWeek" equal to the current day of the week will get a reminder.
OK what I would suggest, is this:
Don't create individual reminders for each day you need a reminder. Give the DB the reminder, start/end dates, and the periodicity of the check (daily, weekly, monthly), and another column to keep track of the last time the user saw a reminder.
something like:
column: | ID | title | Desc | Start | End | Period | lastCheck |
---------------------------------------------------------------------------------------
type: | INT | varchar(100) | varchar(300)| Date | Date| INT (or Enum)| Date
The whole idea is, if the user skips a day you don't need to remind them twice, and you don't really care about what happened to expired reminders, just the most recent.
Assuming the following:
no-repeat = 0
daily = 1
weekly = 2
monthly = 3
you could pull all the reminders you need for a particular date by using: (assuming SQL Server, you didn't specify)
SELECT * FROM Reminder
WHERE (GetDate() BETWEEN Start AND End)
AND ((Period = 0 AND lastChecked IS NULL)
OR (Period = 1 AND GetDate() > DATEADD(day,1,lastChecked))
OR (Period = 2 AND GetDate() > DATEADD(week,1,lastChecked))
OR (Period = 3 AND GetDate() > DATEADD(month,1,lastChecked)));
If you want the reminder to be 24 hours/1 week/1 month exactly from the last time checked that will be fine. otherwise use CONVERT (date, GETDATE()) to ignore the time the user checked.
Finally, update lastChecked to the current time after the user dismisses a reminder.
Related
I have a table which contains the products details, If it is a new product the status will be 1.
Once it got purchased, the status will change to 2.
My requirement is to send mail to the owner if the product remains in status 1 for more than 5 minutes.
Help me out to proceed further, what are all the ways to do so.
Maybe you can add a field like "LastStatusChangedOn", which is a DateTime (or a DateTimeOffset if you need to keep account with different time zones).
And then just select all Products where the difference between the current time and the LastStatusChangedOn is greater than 5 minutes.
Without the exact database structure, it's impossible to give a complete sample, but something like this?
SELECT * FROM Products WHERE DateDiff(minute, LastStatusChangeOn, getdate()) > 5
My dataset provides a monthly snapshot of customer accounts. Below is a very simplified version:
Date_ID | Acc_ID
------- | -------
20160430| 1
20160430| 2
20160430| 3
20160531| 1
20160531| 2
20160531| 3
20160531| 4
20160531| 5
20160531| 6
20160531| 7
20160630| 4
20160630| 5
20160630| 6
20160630| 7
20160630| 8
Customers can open or close their accounts, and I want to calculate the number of 'new' customers every month. The number of 'exited' customers will also be helpful if this is possible.
So in the above example, I should get the following result:
Month | New Customers
------- | -------
20160430| 3
20160531| 4
20160630| 1
Basically I want to compare distinct account numbers in the selected and previous month, any that exist in the selected month and not previous are new members, any that were there last month and not in the selected are exited.
I've searched but I can't seem to find any similar problems, and I hardly know where to start myself - I've tried using CALCULATE and FILTER along with DATEADD to filter the data to get two months, and then count the unique values. My PowerPivot skills aren't up to scratch to solve this on my own however!
Getting the new users is relatively straightforward - I'd add a calculated column which counts rows for that user in earlier months and if they don't exist then they are a new user:
=IF(CALCULATE(COUNTROWS(data),
FILTER(data, [Acc_ID] = EARLIER([Acc_ID])
&& [Date_ID] < EARLIER([Date_ID]))) = BLANK(),
"new",
"existing")
Once this is in place you can simply write a measure for new_users:
=CALCULATE(COUNTROWS(data), data[customer_type] = "new")
Getting the cancelled users is a little harder because it means you have to be able to look backwards to the prior month - none of the time intelligence stuff in PowerPivot will work out of the box here as you don't have a true date column.
It's nearly always good practice to have a separate date table in your PowerPivot models and it is a good way to solve this problem - essentially the table should be 1 record per date with a unique key that can be used to create a relationship. Perhaps post back with a few more details.
This is an alternative method to Jacobs which also works. It avoids creating a calculated column, but I actually find the calculated column useful to use as a flag against other measures.
=CALCULATE(
DISTINCTCOUNT('Accounts'[Acc_ID]),
DATESBETWEEN(
'Dates'[Date], 0, LASTDATE('Dates'[Date])
)
) - CALCULATE(
DISTINCTCOUNT('Accounts'[Acc_ID]),
DATESBETWEEN(
'Dates'[Date], 0, FIRSTDATE('Dates'[Date]) - 1
)
)
It basically uses the dates table to make a distinct count of all Acc_ID from the beginning of time until the first day of the period of time selected, and subtracts that from the distinct count of all Acc_ID from the beginning of time until the last day of the period of time selected. This is essentially the number of new distinct Acc_ID, although you can't work out which Acc_ID's these are using this method.
I could then calculate 'exited accounts' by taking the previous months total as 'existing accounts':
=CALCULATE(
DISTINCTCOUNT('Accounts'[Acc_ID]),
DATEADD('Dates'[Date], -1, MONTH)
)
Then adding the 'new accounts', and subtracting the 'total accounts':
=DISTINCTCOUNT('Accounts'[Acc_ID])
I have a Table called SR_Audit which holds all of the updates for each ticket in our Helpdesk Ticketing system.
The table is formatted as per the below representation:
|-----------------|------------------|------------|------------|------------|
| SR_Audit_RecID | SR_Service_RecID | Audit_text | Updated_By | Last_Update|
|-----------------|------------------|------------|------------|------------|
|........PK.......|.......FK.........|
I've constructed the below query that provides me with the appropriate output that I require in the format I want it. That is to say that I'm looking to measure how many tickets each staff member completes every day for a month.
select SR_audit.updated_by, CONVERT(CHAR(10),SR_Audit.Last_Update,101) as DateOfClose, count (*) as NumberClosed
from SR_Audit
where SR_Audit.Audit_Text LIKE '%to "Completed"%' AND SR_Audit.Last_Update >= DATEADD(day, -30, GETDATE())
group by SR_audit.updated_by, CONVERT(CHAR(10),SR_Audit.Last_Update,101)
order by CONVERT(CHAR(10),SR_Audit.Last_Update,101)
However the query has one weakness which I'm looking to overcome.
A ticket can be reopened once its completed, which means that it can be completed again. This allows a staff member to artificially inflate their score by re-opening a ticket and completing it again, thus increasing their completed ticket count by one each time they do this.
The table has a field called SR_Service_RecID which is essentially the Ticket number. I want to put a condition in the query so that each ticket is only counted once regardless of how many times its completed, while still honouring the current where clause.
I've tried sub queries and a few other methods but haven't been able to get the results I'm after.
Any assistance would be appreciated.
Cheers.
Courtenay
use as
COUNT(DISTINCT(SR_Service_RecID)) as NumberClosed
Use:
COUNT(DISTINCT SR_Service_RecID) as NumberClosed
I'm designing a fact table for SSAS and this is the first time I'm trying my hand at this as this is to be a prototype system just to show what could be done and to show to someone to decide if it what they are after.
I've made up some data and am now trying to create the fact table. The cube will be looking at referrals and what I'm trying to show is the information over time showing the number of referrals that opened in a month, number that closed in a month and the number that were open at any point in the month (i.e. they could have opened in previous month and closed in a future month).
How is it best to design these measure is where I'm stuck. Should it be three fact tables or can I get away with one? If I do three fact tables, I can link on the record number and the open date to get number that opened in a month, I can link on record number and closed date to create number that closed in a month, but the one I have no idea on is to describe when it was open at any point in the month. For this table would I need to create a row for every day for every referral? This seems a bit intensive and so immediately I thought it was wrong.
So the questions are twofold:
Can I do the three measures in one table and if so what is the best method for this?
What is the best method for the open at any point in the month count?
Any thoughts would be most appreciated as I truely am a beginner at this and all I have to aid me is google as I have a short deadline for this.
Dimensions I have:
Demographics: Record number; Gender; Ethnicity; Birth date;
Referral: Record number; Open date; End date;
Time: Date; Month; Quarter; Year;
The fact table I initially designed was:
Data:
Record number; Opened_in_month; Closed_in_month; Open_in_month;
Since creating the cube, I can see that the numbers do not match up to what I put in the test data and so I know that I have messed up the fact table and it's that table I need to re-create.
I have little experience with creating cubes in SSAS but i would probably create a view as something like this
ReferallFacts:
Id | IsOpen | DateOpened | OpenedBy | DateClosed | ClosedBy | OpenForMinutes...
CalendarDimension:
ShortDate | Week | Month | Quarter | Year | FinancialWeek...
EmployeeDimension:
Id | FirstName | LastName | LineManager | Department...
DepartmentDimension:
Id | Name | ParentDepartment | Manager | Location...
I don't really see a need for more than one fact table in this case as all of what you describe "by month", "by day" is handled by the calendar dimension.
Here is a really nice walkthough, and also pcteach.me has some good videos on SSAS.
Have you considered an event-based approach, an event being a referral opening or closing?
First of all, you need to determine the granularity level of your fact table. If you need to know the number of open referrals at a specific date and time in a month, then your fact table must be at the lowest granularity (individual referral records):
FactReferrals: ( DateId, TimeId, EventId, RecordNumber, ReferralEventValue )
Here, ReferralEventValue is just an integer value of 1 when a Referral opens, and -1 when a Referral closes. EventId refers to a dimension with only two members: Opened and Closed.
This approach allows you to get the number of closed or opened events over any given time period. Also, by taking the sum of ReferralEventValue from the beginning of time, and up to a certain point in time, you get the exact amount of open referrals at that specific moment. To speed up this sum in SSAS, you could design aggregations or create a separate measure that is the accumulated sum of ReferralEventValue.
Edit: Of course, if you don't need data at individual referral granularity, you could always sum up the ReferralEventValue per day or even month, before loading the fact table.
I need to store values for every day in timeline, i.e. every user of database should has status assigned for every day, like this:
from 1.1.2000 to 28.05.2011 - status 1
from 29.05.2011 to 30.01.2012 - status 3
from 1.2.2012 to infinity - status 4
Each day should have only one status assigned, and last status is not ending (until another one is given). My question is what is effective representation in sql database? Obvious solution is to create row for each change (with the last day the status is assigned in each range), like this:
uptodate status
28.05.2011 status 1
30.01.2012 status 3
01.01.9999 status 4
this has many problems - if i would want to add another range, say from 15.02.2012, i would need to alter last row too:
uptodate status
28.05.2011 status 1
30.01.2012 status 3
14.02.2012 status 4
01.01.9999 status 8
and it requires lots of checking to make sure there is no overlapping and errors, especially if someone wants to modify ranges in the middle of the list - inserting a new status from 29.01.2012 to 10.02.2012 is hard to implement (it would require data ranges of status 3 and status 4 to shrink accordingly to make space for new status). Is there any better solution?
i thought about completly other solution, like storing each day status in separate row - so there will be row for every day in timeline. This would make it easy to update - simply enter new status for rows with date between start and end. Of course this would generate big amount of needless data, so it's bad solution, but is coherent and easy to manage. I was wondering if there is something in between, but i guess not.
more context: i want moderator to be able to assign status freely to any dates, and edit it if he would need to. But most often moderator will be adding new status data ranges at the end. I don't really need the last status. After moderator finishes editing whole month time, I need to generate raport based on status on each day in that month. But anytime moderator may want to edit data months ago (which would be reflected on updated raports), and he can put one status for i.e. one year in advance.
You seem to want to use this table for two things - recording the current status and the history of status changes. You should separate the current status out and move it up to the parent (just like the registered date)
User
===============
Registered Date
Current Status
Status History
===============
Uptodate
Status
Your table structure should include the effective and end dates of the status period. This effectively "tiles" the statuses into groups that don't overlap. The last row should have a dummy end date (as you have above) or NULL. Using a value instead of NULL is useful if you have indexes on the end date.
With this structure, to get the status on any given date, you use the query:
select *
from t
where <date> between effdate and enddate
To add a new status at the end of the period requires two changes:
Modify the row in the table with the enddate = 01/01/9999 to have an enddate of yesterday.
Insert a new row with the effdate of today and an enddate of 01/01/9999
I would wrap this in a stored procedure.
To change a status on one date in the past requires splitting one of the historical records in two. Multiple dates may require changing multiple records.
If you have a date range, you can get all tiles that overlap a given time period with the query:
select *
from t
where <periodstart> <= enddate and <periodend> >= effdate