SQL calculate number of days in month excluding weekends and holidays days - sql

I have approximately the same table (excluding count column). I want to calculate the number of working days (Mon-Fri) and exclude public holidays.
I tried to try the following query
SELECT count(distinct(date)) from MYDB where dummy <> 1
However, it gives the only total number of days including weekends. Additionally, if use this command it counts distinct dates, however, my dates do not show a full month, so another logic should've used. Could you help to figure out which code is better to use?

there should be a function in Vertica that extracts weekday from date, so to exclude weekends you'll need to add another condition like
extract(dow from date) not in (6,0)
(6 is Sat, 0 is Sun in this case)

Related

Calculating the holidays of employees without counting the weekends

I'm using Microsoft Access to calculate the number of holidays of doctors. Doctors have up to 31 days for holidays per year from where I extract the count of holidays.
However I don't want to count the weekends between start and end days.
Currently my code is the following, which counts the weekends:
TRANSFORM 31-Nz(Sum(DateDiff("d",DateAdd("d",-1,leaves.leave_starting_date),leaves.leave_end_date)),0) AS Days
SELECT doctors.Name
FROM doctors LEFT JOIN leaves ON doctors.ID = leaves.doctor_id
GROUP BY doctors.Name
PIVOT Year(leaves.leave_starting_date);
Any help?
Replace DateDiff with a function that excludes weekends (and, optionally, public holidays as well) from the difference in calendar days.
An example is my function DateDiffWorkdays posted here.

Wrong US week number calculation for 1st jan using datepart

SQL server DATEPART function has two options to retrieve week number;
ISO_WEEK and WEEK. I Know the difference between the two, I want to have week numbers based on Sunday start standard as followed in the US; i.e. WEEK. But it doesn't handles partial weeks the way I expected. e.g.
SELECT DATEPART(WEEK,'2015-12-31') --53
SELECT DATEPART(WEEK,'2016-01-01') --1
SELECT DATEPART(WEEK,'2016-01-03') --2
gives two different week numbers for a single week, divided in two years. I wanted to implement something like in the following link for week days.
Week numbers according to US standard
Basically I would like something like this;
SELECT DATEPART(WEEK,'2015-12-31') --1
SELECT DATEPART(WEEK,'2016-01-01') --1
SELECT DATEPART(WEEK,'2016-01-03') --2
EDIT:
Basically I am not good with the division of a single week into two, I have to perform some calculations based on week numbers and the fact that a single week to be divided isn't acceptable. So if above isn't possible.
Is it possible that the week number one would start from 2016-01-03. i.e. what I would in that case would be something like this:
SELECT DATEPART(WEEK,'2015-12-31') --53
SELECT DATEPART(WEEK,'2016-01-01') --53
SELECT DATEPART(WEEK,'2016-01-03') --1
If you want the US numbering, you can do this by taking the WEEK number of the end of the week rather than the date itself.
First ensure that the setting for first day of the week is in fact Sunday on your system. You can verify this by running SELECT ##DATEFIRST; this should return 7 for Sunday. If it doesn't, run SET DATEFIRST 7; first.
SELECT
end_of_week=DATEADD(DAY, 7-(DATEPART(WEEKDAY, '20151231')), '20151231'),
week_day=DATEPART(WEEK, DATEADD(DAY, 7-(DATEPART(WEEKDAY, '20151231')), '20151231'));
Which will return 2016/01/02 - 1.
If you wish generate week number of a date, it will return the week number of the year(input date)
Thus, I think sql server treat '2015-12-31' as the last week of 2015.

How do I get the number of days in a month for the specific date in that row of data using SQL?

For example, if I have a data set including two columns, one which shows the month as a number and the other which shows the year (result of grouping my data using GROUP BY), I want to add another column called 'Days in the month' which will display the number of days in the respective month. Is there a way I can do this? Is there some function I can add in the SELECT clause?
I want to do this since there are further calculations I need to do with that number for each row.
In SQL Server 2012+, you can use:
select day(eomonth(datecol))
eomonth() gets the last day of the month. day() just returns the day of the month -- the number of days in the month, in this case.
For older SQL Server versions, I use the following:
DAY(DATEADD(MONTH, DATEDIFF(MONTH, -1, date_column)- 1, -1))
Much less elegant than the previous answer, but functional.

Get the month and year now then count the number of rows that are older then 12 months in SQL/Classic ASP

I know this one is pretty easy but I've always had a nightmare when it comes to comparing dates in SQL please can someone help me out with this, thanks.
I need to get the month and year of now then compare it to a date stored in a DB.
Time Format in the DB:
2015-08-17 11:10:14.000
I need to compare the month and year with now and if its > 12 months old I will increment a count. I just need the number of rows where this argument is true.
I assume you have a datetime field.
You can use the DATEDIFF function, which takes the kind of "crossed boundaries", the start date and the end date.
Your boundary is the month because you are only interested in year and month, not days, so you can use the month macro.
Your start time is the value stored in the table's row.
Your end time is now. You can get system time selecting SYSDATETIME function.
So, assuming your table is called mtable and the datetime object is stored in its date field, you simply have to query:
SELECT COUNT(*) FROM mtable where DATEDIFF(month, mtable.date, (SELECT SYSDATETIME())) > 12

Sql select statement that will bring back my data in weeks, using derived tables with JasperReports

I'm currently running the following sql statement in JasperReports Server to bring back my data using derived tables.
Select count(createddate) as ModulesCreatedDuringPastWeek,
count(updateddate) as ModulesUpdatedDuringPastWeek,
createddate,
updateddate
from merchendisingmodule
group by merchendisingmodule.createddate, merchendisingmodule.updateddate
However when grouping my data, I am only able to do it in Year, quarter, month and day. However for my report I'm needing the data to be group weeks, and so I was wondering what I will need to add to my code to do this.
DATEADD(D,-DATEPART(weekday,createddate)+1,createddate)
I use this method to prevent issues around the year transitions (week 53 in first days of januari and also in the last days of december, will group days together that are 360 days apart).
I use the first day of the week, instead of week numbers. I can use these dates to group by.
Also this will ensure that every week is 7 days long, instead of the last week of the year being only 3 or 4 days long.
Btw, in this example the first day of the week is sunday.
If your dates include time, use:
CAST(FLOOR(CAST(createddate AS FLOAT)) AS DATETIME)
instead of createddate in the above SYNTAX