I have a view that lists employee (EmpID), request number (ReqNo), date request was opened (OpenDate) and the date it was moved to the next step in the process (AssignDate). What I am trying to do is get an average of the daily queue size. If EmpID 001 has 20 requests on 1/1/13, then has 24 on 1/2/13, 21 on 1/3/13 the average over 3 days should be 21.66, rounded up to 22. I have the following view:
CREATE VIEW EmpReqs
AS
SELECT [EmpID], [OpenDate], [AssignDate], [ReqID]
FROM [Metrics].[dbo].[Assignments]
WHERE OpenDate BETWEEN '01/01/2013' AND '12/31/2013' AND
[EmpID] IS NOT NULL AND
[ReqNo] NOT LIKE 'M%'
I then wrote a query to pull individual employee's queues per day:
/* First attempt to generate daily queue #s */
SELECT * FROM BLReqs
WHERE [BusLiaison] LIKE 'PN' AND
[OpenDate] <= '11/15/2013' AND
[AssignDate] > '11/15/2013'
Because no one has attempted to pull this information before, I have no way of verifying how accurate the above is. I tried using current dates, since I can see those in our database to compare but the code doesn't work, nothing is returned when I change the dates to 2014 and run my query.
What is the easiest way to verify that my code is correct, short of manually counting a day's queue?
Can anyone see any issues with the above scripts?
Is there a way to get the above code to work with current dates?
This question is really hard to answer because it is kind of broad and has little information at the same time. I'll try anyway:
Because no one has attempted to pull this information before, I have
no way of verifying how accurate the above is.
Try checking the result of this query for a few sampled dates.
I tried using current dates, since I can see those in our database to
compare but the code doesn't work, nothing is returned when I change
the dates to 2014 and run my query.
So clearly, the query is not working. You should probably find out why. Run the query for a date of which you know that it should return results but doesn't. Remove conditions one by one to see which one is incorrectly removing all rows. This should be enough to identify the bug.
Can anyone see any issues with the above scripts?
No, looks fine. A very simple query. That's why I said that we have too little information. There is some key piece of information missing that allows us to find the bug.
Is there a way to get the above code to work with current dates?
Stop staring at the code and hoping for a revelation. Debug it. Experiment.
Related
I am currently working on a task that queries for a certain type of record. If it is null or less than 1 for the current date an email sends out. That part is pretty straight forward. Now a requirement has been added to get a count for how many days consecutively this has been happening.
If there are no records in the table, there are no dates to check on, so I'm not entirely sure what to do.
If I query on multiple dates then it destroys the code which is built upon emailing on a null result.
Recently I created an automated production scheduling tool through Excel that assigns a rank to items being produced in the same process, and then uses that rank in combination with the workload to create a schedule.
It functions exactly the way it is intended to, but due to the large amount of data and it being excel it has very slow performance, which is why I am looking to move the calculations over to SQL.
The general logic is like this:
-Always produce everything from the first day before the second day
-Always produce items from an earlier rank before items from a later rank
You can see how this plays out in the image below, where the line has 21.5 hours today, so items will be produced on day 1 until it equals 21.5, where the remainder is then carried over to day 2 and so on.
I was able to do this in excel using lengthy positional based formulas, but I am trying to think of a way to get the same result in SQL without having to rely on looking at the row above.
I am not sure how to convey something like 'Subtract from the available time production time of higher priority items produced on the same day'.
I apologize if the question is unclear, but any advice would be appreciated.
Image of Production Hours Cascading by Priority and Day
Example of Position-Based Fomula
Thanks to shawnt00, that put me in the right direction. Ultimately I had to modify the case statements a bit to go off of the cumulative total instead, but I was able to get the desired results using a sum() Over (partition by order by ) statement.
I have a particular data set that consists of information for projects our company works on. Each project can go through five different statuses and we have a column that records each date the project is put into that particular status.
Now for the Excel part. We are trying to calculate the days in each status and find the total project time. The total is easy to do, because I can use network days between the project submitted date and the project go live date. The statuses, however, are giving me issues because sometimes a project will skip a status, leaving the date field empty. So what happens is a project goes from status B to status D, the formula for days in status "B" look for a date in column "C" to use as the second date in a NETWORKDAYS formula. When it is empty, the IF argument tells the formula to use TODAY() as the second date. What I need it to do is the search the columns to the right (within the given range of A:E for that row) and use that date if it exists. If not, then it can default to TODAY() because this would be an "active" project that has not moved on.
=IF(IF(OR([#STALLED]<>"",[#CANCELED]<>""),"",IF([#INTAKEDATE]="","",IF([#SCOPEATE]="",NETWORKDAYS([#INTAKEDATE],TODAY()),(NETWORKDAYS([#STATUSADATE],[#SCOPEATE])))))<0,"",(IF(OR([#STALLED]<>"",[#CANCELED]<>""),"",IF([#INTAKEDATE]="","",IF([#SCOPEATE]="",NETWORKDAYS([#INTAKEDATE],TODAY()),(NETWORKDAYS([#STATUSADATE],[#SCOPEATE])))))))
This is done for each of the statuses so the table looks something like this:
PROJECTID PROJECTNAME INTAKEDATE SCOPEATE BUILDDATE TESTDATE GOLIVEDATE INTAKEDAYS SCOPEDAYS BUILDDAYS TESTDAYS
If there is any Macro or better formula someone could help me figure out, I'd appreciate it. There is also another field that gives the current status or if the project is considered live if that helps at all. I have excel-block right now and cant think of anything that makes sense for this.
So I figured it out using MIN and by adjusting the IF formulas a bit. Whoever it was that posted about MAX earlier, really helped me out getting me down this path. Kudos to you sir/madam.
I had to add the check to see if SCOPEDATE=BUILDDATE because without that it was returning 1 if the dates matched, with was adding one more day when compared to running the networkdays from INTAKEDATE to GOLIVEDATE.
=IF(OR([#STALLED]<>"",[#CANCELED]<>""),"",
IF([#SCOPEDATE]="","",
IF([#SCOPEDATE]=[#BUILDDATE],0,
IF(NETWORKDAYS([#SCOPEDATE],(MIN([#BUILDDATE],[#TESTDATE],[#GOLIVEDATE])))<0,NETWORKDAYS([#SCOPEDATE],TODAY()),NETWORKDAYS([#SCOPEDATE],(MIN([#BUILDDATE],[#TESTDATE],[#GOLIVEDATE])))))))
I hope this is helpful for someone else.
Im making a simple booking system for our projectors at work.
Here is the scenario. Each projectors can have its availability set to quarter hour segments throughout the entire day. i.e projector 1 is available between 8:15am - 1:45pm and 3pm-5:15pm each day (can also be changed to have different availabilities set for each day). A projector can be booked for anytime time segment during the day as long as it is available. So ive got that setup in my sql database (with my asp.net mvc front end).
The question i have is what is the best way to search on this scenario. i.e. UserA comes in and says find me the projectors that are available this friday between 12pm-3pm. Im struggling to write an efficient sql query that will filter this. My best option so far is to pull back all projectors and than programatically work out if they are available and not booked between this time. It works but it is incredibly inefficient. I stumbled an idea of using a temp table generated by a stored proc that can than be filtered but it isnt quite there.
Has anyone got any ideas how i could approach this?
Thanks in advance
I would probably have a table called ProjectorReservations which contained a start time and end time (amongst other fields you might care about i.e. who is renting the projector).
Searching a projector would look something like this:
SELECT projectorName
FROM Projectors
WHERE NOT EXISTS
(SELECT 1 FROM ProjectorReservations
WHERE Projectors.projectorName = ProjectorReservations.projectorName
AND (ProjectorReservations.startTime < {end_time}
OR ProjectorReservations.endTime > {start_time}))
That pretty much checks to make sure no reservations start before the one you are looking for ends and vice versa. Obviously you will need to swap in your fields accordingly but that should give you the general idea
We are currently developing an application in which multiple entities have associated opening hours. Opening hours may span multiple days, or may be contained within a single day.
Ex. Opens Monday at 6:00 and closes at Friday at 18:00.
Or
Opens Monday at 06:00 and closes Monday at 15:00.
Also, an entity may have multiple sets of opening hours per day.
So far, the best design I have found, is to define an opening hour to consist of the following:
StartDay, StartTime, EndDay and EndTime.
This design allows for all the needed flexibility. However, data integrity becomes an issue. I cannot seem to find a solution that will disallow overlapping spans (in the database).
Please share your thoughts.
EDIT: The database is Microsoft SQL Server 2008 R2
Consider storing your StartDay and StartTime, but then have a value for the number of hours that it's open. This will ensure that your closing datetime is after the opening.
OpenDate -- day of week? e.g. 1 for Monday
OpenTime -- time of day. e.g. 08:00
DurationInHours -- in hours or mins. e.g. 15.5
Presuming a robust trigger framework
On insert/update you would check if the new start or end date falls inside of any existing range. If it does then you would roll back the change.
CREATE TRIGGER [dbo].[mytable_iutrig] on [mytable] FOR INSERT, UPDATE AS
IF (SELECT COUNT(*)
FROM inserted, mytable
WHERE (inserted.startdate < mytable.enddate
AND inserted.startdate > mytable.startdate)
OR (inserted.enddate < mytable.enddate
AND inserted.enddate > mytable.startdate)) > 0
BEGIN
RAISERROR --error number
ROLLBACK TRANSACTION
END
Detecting and preventing overlapping time periods will have to be done at the application level. Of course you can attempt to use a trigger in the database but in my opinion this is not a database issue. The structure that you came up with is fine, but your application logic will have to take care of the overlap.
There's an article by Joe Celko on the SimpleTalk website, over here, that discusses a similar issue, and presents am elegant if complex solution. This is probably applicable to your situation.
A table with a single column TimeOfChangeBetweenOpeningAndClosing?
More seriously though, I would probably not worry too much about coming up with a single database structure for representing everything, eventually you'll probably want want a system involving recurrences, planned closures etc. Persist objects representing those, and then evaluate them to find out the closing/opening times.
This looks like a good solution, but you'll have to write a custom validation function. The built in database validation (i.e. unique, less than x, etc.) isn't going to cut it here. To ensure you don't have overlapping spans, every time you insert a record into the database, you're going to have to select existing records and compare...
First the logic, two spans will overlap if the start value of one falls between the start/end of the other. This is much easier if we have datetimes combined, instead of date1,time1 and date2,time2. So a query to find an overlap looks like this.
select openingId
from opening o1
join opening o2 on o1.startDateTime
between o2.startDateTime
AND o2.endDateTime
You can put this into a trigger and throw an error if a match is found.