Matching date with calculated DATEADD date - sql

I am trying to create a table with columns containing the current date, prior year date, and additional column for the total sum revenue as below:
cur_date | py_date | py_rev
I'm trying to compare revenue across any daily period across years. Assume all dates and revenue values are included in the same SQL Server table.
I attempted to use a case statement using [date] = DATEADD(wk,-52,[date]) as the condition to return the appropriate total. The full line code is below:
select
[date] as cur_date,
DATEADD(wk,-52,[date]) py_date,
SUM(case when [date] = DATEADD(wk,-52,[date]) then sum_rev else 0 end) as py_rev
from summary
group by [date]
When running this code the py_date is as expected but py_rev returns 0 as if there is no match. What's most confusing is if I hard code a random date in place of the DATEADD portion then a total is returned. I have also tried CAST to format both date and the DATEADD portion as date with no luck.
Is there something about DATEADD that will not match to other date columns that I'm missing?

If you want the previous years revenue, then lag() is one method. This works assuming that "previous year" means 52 weeks ago and you have records for all dates:
select [date] as cur_date,
dateadd(week, -52, [date]) as py_date,
lag(sum_rev, 52 * 7) over (order by date) as py_rev
from summary;
If you do not have records for all dates, then another approach is needed. You can use a LEFT JOIN:
select s.date, dateadd(week, -52, s.[date]),
sprev.sum_rev as py_rev
from summary s left join
summary sprev
on sprev.date = dateadd(week, -52, s.[date]);

Related

Generate List of dates between 2 dates for each Id

I have a table with PersonId's that each have a FirstSubscription date and LastSubscriptionDate.
What I need to do is between those 2 dates, generate 1 date for each month. This is for reporting purposes on the front end, as this data will end up inside PowerBI and I need these dates to join to a ReportingCalendar.
This Calendar is accessible by SQL so it can be used in this calculation. I am using it to generate the dates (using first of the month) between the First and LastSubDate but I need to find a way to join this with the rest of the ID's that way I get a list of date for each ID.
Here is my code to generate the dates.
DECLARE #MinDate DATE
DECLARE #MaxDate DATE
SET #MinDate = '2020-08-31'
SET #MaxDate = '2022-08-30'
SELECT DATEADD(month, DATEDIFF(month, 0, date), 0)
FROM dbo.ReportingCalendar
WHERE Date >= #MinDate
AND Date < #MaxDate
GROUP BY
DATEADD(month, DATEDIFF(month, 0, date), 0)
My PersonSubscription table looks like this
|PersonId|FirstSubDate|LastSubDate|
|--------|------------|-----------|
|1186 |8/31/2020 |8/30/2022 |
|2189 |7/30/2019 |7/31/2021 |
So I would want to end up with an output where each PersonId has 1 entry for each month between those 2 dates. So PersonId has 25 entries from 8/2020 until 8/2022. We don't care about the actual date of the sub since this data is looked at monthly and will primarily be looked at using a Distinct Count each month, so we only care if they were subbed at any time in that month.
I just needed to do a Cross Apply.
I took my code that got me all of the PersonId's and their FirstSubDate and LastSubDate and then did a cross apply to the code I listed above, referencing the MinDate and MaxDate with the FirstSubDate and LastSubDate.

SQL Server query to get total against each month of a year and return the year and month in date format not the string format

I have a situation in which i have to calculate "Total" for each month of a year and i have to show total for each month of the year while maintaining datetime format of the date.i am writing the following query:
SELECT [DATE_FORMATION], sum(CO) CO, sum(Total_Members) Total_Members
from (
select convert(varchar(7),CAST([DATE_FORMATION] AS DATE),126) as [DATE_FORMATION],
count([CO_ID]) as CO,
sum(convert(int,[TOTAL_MEMBERS])) as Total_Members
from COCores
where cast([DATE_FORMATION] as date) >= Dateadd(Month, Datediff(Month, 0, DATEADD(m, -10, current_timestamp)), 0)
group by [DATE_FORMATION]
) tmp
group by [DATE_FORMATION]
It is giving the accurate answer which i required
but the problem is it generates date in "Varchar" format where as i require it in datetime format so that i can use it further.how can i get this result while keeping the date in datetime format and getting the same result.
Dates have no formats, they are binary values, just like int or decimal or binary. DATE_FORMATION should be a date type, eg date, datetime or datetime2. If the column uses the correct type, the query can be simplified to just :
select
datefromparts(Year(DATE_FORMATION),MONTH(DATE_FORMATION),1) as DATE_FORMATION,
count([CO_ID]) as CO,
sum([TOTAL_MEMBERS]) as Total_Members
from COCores
where
[DATE_FORMATION] as date) >= DATEFROMPARTS(Year(current_timestamp),1,1)
group by
YEAR(DATE_FORMATION),
MONTH(DATE_FORMATION)
DATEFROMPARTS(Year(current_timestamp),1,1) returns the first date of the current year. This is used to return only rows in the current year. The results are grouped by the Year and Month of DATE_FORMATION using the YEAR and MONTH functions. Finally, SELECT returns the first day of each month by using DATEFROMPARTS to generate a date value from the group keys
Queries like this become far easier if you use a Calendar table. A calendar table contains rows for each date eg for 50 years and extra columns for year, month, day, week number, names, etc that can be used to make reporting easier. Calendar tables are heavily indexed, allowing easy querying eg by year, quarter, semester etc.
Assuming DATE_FORMATION is a date, and a Calendar table with date, Year, Month and StartOfMonth columns, you could turn the query into :
select
Calendar.StartOfMonth,
count([CO_ID]) as CO,
sum([TOTAL_MEMBERS]) as Total_Members
from COCores inner join Calendar on DATE_FORMATION=Calendar.date
where
Calendar.Year= Year(current_timestamp)
group by
StartOfMonth
This query would be fast too as it can take advantage of any indexes on Year, Date and StartOfMonth
You can convert all dates to first day of the month like so:
DATEADD(DAY, 1, EOMONTH(DATE_FORMATION, -1))
It produces a DATE. You can use this expression in GROUP BY and in SELECT clause:
SELECT DATEADD(DAY, 1, EOMONTH(DATE_FORMATION, -1)), COUNT(CO_ID) AS CO, SUM(CONVERT(INT, TOTAL_MEMBERS)) AS Total_Members
FROM COCores
WHERE DATE_FORMATION >= -- calculate -10 months
GROUP BY DATEADD(DAY, 1, EOMONTH(DATE_FORMATION, -1))

Grouping all dates as one field and showing the sum of sales

I have converted all dates within my table to reflect as YYYY/MM/01 but I am left with 25 or so of these dates that are all the same and I just want to group them together and I can't figure out how to do it. I'm newish to SQL and was hoping someone could point me in the right direction for this.
Much appreciated!
SELECT
DATEFROMPARTS(YEAR(ReportedDate), MONTH(ReportedDate), 1) AS Date, SUM(Sales) Sales
FROM
dbo.Sales
WHERE
YEAR(ReportedDate) = 2018 AND MONTH(ReportedDate) = 01
GROUP BY
ReportedDate
Because you are grouping by ReportedDate, for every ReportedDate you will get a record, even though you didn't select ReportedDate in your SELECT clause. Think of it as a hidden column in your data. Instead, try grouping by the functions in your select statement.
SELECT
DATEFROMPARTS(YEAR(ReportedDate), MONTH(ReportedDate), 1) AS Date, SUM(Sales) Sales
FROM
dbo.Sales
WHERE
YEAR(ReportedDate) = 2018 AND MONTH(ReportedDate) = 01
GROUP BY
DATEFROMPARTS(YEAR(ReportedDate), MONTH(ReportedDate), 1)
As an alternative to your query I suggest you to use EOMONTH function. You would not need to use extra date functions. And I think it's better to show last day of month than first day when showing totals per month
SELECT
EOMONTH(ReportedDate) AS Date, SUM(Sales) Sales
FROM
dbo.Sales
WHERE
EOMONTH(ReportedDate) = EOMONTH(GETDATE(), -1)
GROUP BY
EOMONTH(ReportedDate)
Notes:
EOMONTH(GETDATE(), -1) gets last day of previous month
Use DATEADD(DD, 1, EOMONTH(ReportedDate, -1)) to get first day of month

SQL : Get last 3 month data (with only available data in the column), not from current month or today?

Anyone help me out on this scenario. I need to get a last 3 month data from particular column, which is not from current date but only from available date.
Ex :
I have one Table named Shop and column named OrderDate, In OrderDate i have only dates until 30-06-2017, but today's date is 07-02-2018. From this i need to get last 3 months data, which is Jun'17, May'17 and Apr'17.
If data available in till July'17 means i need result Jul'17,Jun'17 & May'17. And so on.
Any can help on this to achieve in SQL ?
Thanks in advance.
I assume that column OrderDate is of date or datetime datatype.
select * from Shop
where OrderDate >
(select dateadd(month, -3, max(OrderDate)) from Shop)
I think the easiest way to get this is to select the largest date in that table and use that to create the filter.
So;
Select *
from table
where date >
Dateadd
('m', -3,
( Select Max (date) from table)
)
Apologies in advance for poor formatting
You will have to find the maximum date in the table and use that:
select s.*
from Shop s,
(select convert(date,
format(
dateadd(MONTH, -3, max(OrderDate)), 'yyyyMM01')
,112) as fromDate from Shop) md
where s.OrderDate >= md.fromDate

Query to check number of records created in a month.

My table creates a new record with timestamp daily when an integration is successful. I am trying to create a query that would check (preferably automated) the number of days in a month vs number of records in the table within a time frame.
For example, January has 31 days, so i would like to know how many days in january my process was not successful. If the number of records is less than 31, than i know the job failed 31 - x times.
I tried the following but was not getting very far:
SELECT COUNT (DISTINCT CompleteDate)
FROM table
WHERE CompleteDate BETWEEN '01/01/2015' AND '01/31/2015'
Every 7 days the system executes the job twice, so i get two records on the same day, but i am trying to determine the number of days that nothing happened (failures), so i assume some truncation of the date field is needed?!
One way to do this is to use a calendar/date table as the main source of dates in the range and left join with that and count the number of null values.
In absence of a proper date table you can generate a range of dates using a number sequence like the one found in the master..spt_values table:
select count(*) failed
from (
select dateadd(day, number, '2015-01-01') date
from master..spt_values where type='P' and number < 365
) a
left join your_table b on a.date = b.CompleteDate
where b.CompleteDate is null
and a.date BETWEEN '01/01/2015' AND '01/31/2015'
Sample SQL Fiddle (with count grouped by month)
Assuming you have an Integers table*. This query will pull all dates where no record is found in the target table:
declare #StartDate datetime = '01/01/2013',
#EndDate datetime = '12/31/2013'
;with d as (
select *, date = dateadd(d, i - 1 , #StartDate)
from dbo.Integers
where i <= datediff(d, #StartDate, #EndDate) + 1
)
select d.date
from d
where not exists (
select 1 from <target> t
where DATEADD(dd, DATEDIFF(dd, 0, t.<timestamp>), 0) = DATEADD(dd, DATEDIFF(dd, 0, d.date), 0)
)
Between is not safe here
SELECT 31 - count(distinct(convert(date, CompleteDate)))
FROM table
WHERE CompleteDate >= '01/01/2015' AND CompleteDate < '02/01/2015'
You can use the following query:
SELECT DATEDIFF(day, t.d, dateadd(month, 1, t.d)) - COUNT(DISTINCT CompleteDate)
FROM mytable
CROSS APPLY (SELECT CAST(YEAR(CompleteDate) AS VARCHAR(4)) +
RIGHT('0' + CAST(MONTH(CompleteDate) AS VARCHAR(2)), 2) +
'01') t(d)
GROUP BY t.d
SQL Fiddle Demo
Explanation:
The value CROSS APPLY-ied, i.e. t.d, is the ANSI string of the first day of the month of CompleteDate, e.g. '20150101' for 12/01/2015, or 18/01/2015.
DATEDIFF uses the above mentioned value, i.e. t.d, in order to calculate the number of days of the month that CompleteDate belongs to.
GROUP BY essentially groups by (Year, Month), hence COUNT(DISTINCT CompleteDate) returns the number of distinct records per month.
The values returned by the query are the differences of [2] - 1, i.e. the number of failures per month, for each (Year, Month) of your initial data.
If you want to query a specific Year, Month then just simply add a WHERE clause to the above:
WHERE YEAR(CompleteDate) = 2015 AND MONTH(CompleteDate) = 1