I have a problem where I need to query a database which includes multiple lines of trade activity for the past 90 days. Currently the query is built to determine the average amount over the 90 day period - so each day has a single exposure value and the query helps us determine the average exposure over 90 days by just summing the daily values and then dividing by 90. And it does this as the date rolls forward, so the value is updated each day the query is run.
The above is simple enough to execute, but now I need to determine the average month-end amounts for the past 3 months. I've figured out how to pull just month-end dates, but not sure how to join that with the current query. Additionally, needs to be able to update itself rolling forward.
/* Test query below */
DECLARE #Date DATETIME = Getdate()
DECLARE #daycount INT = 90
DECLARE #startDate DATETIME = Dateadd(dd, #daycount*-1, #Date)
SELECT sub.Instrument,
( Sum(sub.GrossExposure) / #daycount ) AS AvgGrossExposure
FROM (SELECT DateField,
Instrument,
GrossExposure
FROM table
WHERE DateField <= #Date
AND Datefield >= #startDate
) sub
GROUP BY Instrument
To calculate month-ends in the past 90 days, I've fiddled around with this, but it also includes today's date and I do not need that value in this case.
/* Test query for month-end dates, past 90 days */
DECLARE #Date DATETIME = GetDate()
DECLARE #daycount INT = 90
DECLARE #startDate DATETIME = Dateadd(dd, #daycount*-1, #Date)
SELECT max(datefield) AS month_ends
FROM table
WHERE datefield <= #Date
AND datefield >= #startDate
GROUP BY month(datefield),
year(datefield)
ORDER BY month_ends
Give this a try - you can use a common table expression to append the month end date of each DateField value using EOMONTH(DateField), and then use that in your GROUP BY, with the Average of all GrossExposure values that have that same EOMONTH value for each instrument.
WITH CTE AS (
SELECT EOMONTH(DateField) AS EndOfMonthDate
,DateField
,Instrument
,GrossExposure
FROM TABLE
WHERE DateField BETWEEN GETDATE()-90 AND GETDATE()
)
SELECT CTE.Instrument,
CTE.EndOfMonthDate,
AVG(CTE.GrossExposure) AS AvgGrossExposure
FROM CTE
GROUP BY CTE.Instrument, CTE.EndOfMonthDate
I am looking for an SQL query for the sum of minutes between start and end date for a particular month.
Eg.
I'm looking for the amount of minutes used in February.
Start Date Time: 27-02-13 00:00:00
End Date Time: 05-03-13 00:00:00
Because im only looking for the sum of february it should only give me the sum of 3 days (in minutes) and not the extra 5 days going into march.
I have no way to validate it but it should looks like:
SELECT DATEDIFF(minute, startDate, CASE when endDate > EOMONTH(startDate) THEN EOMONTH(startDate) ELSE endDate END) FROM ...
GL!
I left it in steps to illustrate each process. You can of course easily collapse this down, but I'll leave it up to you to do that.
Here's my solution http://www.sqlfiddle.com/#!3/b4991/1/0
SELECT *
, DATEDIFF(minute, StartDAte, NewEndDate) AS TotalMinutes
FROM
(
SELECT *
, CASE WHEN TempDate > EndDate THEN EndDate ELSE TempDate END AS NewEndDate -- Either EOM or old EndDate, whichever is smaller
FROM
(
SELECT *
, DATEADD(month, 1, CAST(Year + '-' + Month + '-1' AS DATETIME)) AS TempDate -- first day of the next month
FROM
(
select *
, CAST(DATEPART(month, StartDate) AS char(2)) AS Month
, CAST(DATEPART(year, StartDate) AS char(4)) AS Year
from tbl
) t0
) t1
) t2
First I get the year and month from the original StartDate. I then construct a first-of-the-month date from that. I then add one month to that to get me the first-of-the-month of the next month. Then I check if that new date is > or < the previous EndDate. I take the smaller of the two dates. Then I use the original StartDate and whichever is smaller between the TempDate and EndDate to determine my total minutes.
See Also EOMONTH: http://msdn.microsoft.com/en-us/library/hh213020.aspx
Look into using DATEDIFF -- this will just help you to get started:
SELECT DATEDIFF(minute, starttime, endtime)
http://msdn.microsoft.com/en-us/library/ms189794.aspx
To get the last day of the start month, use DATEADD:
SELECT DATEADD(second,-1,DATEADD(month, DATEDIFF(month,0,starttime)+1,0))
SQL Fiddle Demo
I recently had to solve a similar problem, I added two new functions to help with this:
CREATE FUNCTION [dbo].[GREATESTDATE]
(
-- Add the parameters for the function here
#Date1 DATETIME,
#Date2 DATETIME
)
RETURNS DATETIME
AS
BEGIN
IF (#Date1 < #Date2)
RETURN #Date2
ELSE
RETURN #Date1
END
and...
CREATE FUNCTION [dbo].[LEASTDATE]
(
-- Add the parameters for the function here
#Date1 DATETIME,
#Date2 DATETIME
)
RETURNS DATETIME
AS
BEGIN
IF (#Date1 > #Date2)
RETURN #Date2
ELSE
RETURN #Date1
END
Then use them like:
DATEDIFF(D,dbo.GREATESTDATE(#StartDate1,#StartDate2),dbo.LEASTDATE(#EndDate1,#EndDate2))
I need to make a temporary table that holds of range of dates, as well as a couple of columns that hold placeholder values (0) for future use. The dates I need are the first day of each month between $startDate and $endDate where these variables can be several years apart.
My original sql statement looked like this:
select dbo.FirstOfMonth(InsertDate) as Month, 0 as Trials, 0 as Sales
into #dates
from customer
group by dbo.FirstOfMonth(InsertDate)
"FirstOfMonth" is a user-defined function I made that pretty much does what it says, returning the first day of the month for the provided date with the time at exactly midnight.
This produced almost exactly what I needed until I discovered there were occasionally gaps in my dates where I had a few months were there were no records insert dates. Since my result must still have the missing months I need a different approach.
I have added the following declarations to the stored procedure anticipating their need for the range of the dates I need ...
declare $startDate set $startDate = select min(InsertDate) from customer
declare $endDate set $endDate = select max(InsertDate) from customer
... but I have no idea what to do from here.
I know this question is similar to this question but, quite frankly, that answer is over my head (I don't often work with SQL and when I do it tends to be on older versions of SQL Server) and there are a few minor differences that are throwing me off.
I needed something similar, but all DAYS instead of all MONTHS.
Using the code from MatBailie as a starting point, here's the SQL for creating a permanent table with all dates from 2000-01-01 to 2099-12-31:
CREATE TABLE _Dates (
d DATE,
PRIMARY KEY (d)
)
DECLARE #dIncr DATE = '2000-01-01'
DECLARE #dEnd DATE = '2100-01-01'
WHILE ( #dIncr < #dEnd )
BEGIN
INSERT INTO _Dates (d) VALUES( #dIncr )
SELECT #dIncr = DATEADD(DAY, 1, #dIncr )
END
This will quickly populate a table with 170 years worth of dates.
CREATE TABLE CalendarMonths (
date DATETIME,
PRIMARY KEY (date)
)
DECLARE
#basedate DATETIME,
#offset INT
SELECT
#basedate = '01 Jan 2000',
#offset = 1
WHILE (#offset < 2048)
BEGIN
INSERT INTO CalendarMonths SELECT DATEADD(MONTH, #offset, date) FROM CalendarMonths
SELECT #offset = #offset + #offset
END
You can then use it by LEFT joining on to that table, for the range of dates you require.
I would probably use a Calendar table. Create a permanent table in your database and fill it with all of the dates. Even if you covered a 100 year range, the table would still only have ~36,525 rows in it.
CREATE TABLE dbo.Calendar (
calendar_date DATETIME NOT NULL,
is_weekend BIT NOT NULL,
is_holiday BIT NOT NULL,
CONSTRAINT PK_Calendar PRIMARY KEY CLUSTERED (calendar_date)
)
Once the table is created, just populate it once in a loop, so that it's always out there and available to you.
Your query then could be something like this:
SELECT
C.calendar_date,
0 AS trials,
0 AS sales
FROM
dbo.Calendar C
WHERE
C.calendar_date BETWEEN #start_date AND #end_date AND
DAY(C.calendar_date) = 1
You can join in the Customers table however you need to, outer joining on FirstOfMonth(InsertDate) = C.calendar_date if that's what you want.
You can also include a column for day_of_month if you want which would avoid the overhead of calling the DAY() function, but that's fairly trivial, so it probably doesn't matter one way or another.
This of course will not work in SQL-Server 2000 but in a modern database where you don't want to create a permanent table. You can use a table variable instead creating a table so you can left join the data try this. Change the DAY to HOUR etc to change the increment type.
declare #CalendarMonths table (date DATETIME, PRIMARY KEY (date)
)
DECLARE
#basedate DATETIME,
#offset INT
SELECT
#basedate = '01 Jan 2014',
#offset = 1
INSERT INTO #CalendarMonths SELECT #basedate
WHILE ( DATEADD(DAY, #offset, #basedate) < CURRENT_TIMESTAMP)
BEGIN
INSERT INTO #CalendarMonths SELECT DATEADD(HOUR, #offset, date) FROM #CalendarMonths where DATEADD(DAY, #offset, date) < CURRENT_TIMESTAMP
SELECT #offset = #offset + #offset
END
A starting point of a useful kludge to specify a range or specific list of dates:
SELECT *
FROM
(SELECT CONVERT(DateTime,'2017-1-1')+number AS [Date]
FROM master..spt_values WHERE type='P' AND number<370) AS DatesList
WHERE DatesList.Date IN ('2017-1-1','2017-4-14','2017-4-17','2017-12-25','2017-12-26')
You can get 0 to 2047 out of master..spt_values WHERE type='P', so that's five and a half year's worth of dates if you need it!
Tested below and it works, though it's a bit convoluted.
I assigned arbitrary values to the dates for the test.
DECLARE #SD smalldatetime,
#ED smalldatetime,
#FD smalldatetime,
#LD smalldatetime,
#Mct int,
#currct int = 0
SET #SD = '1/15/2011'
SET #ED = '2/02/2012'
SET #FD = (DATEADD(dd, -1*(Datepart(dd, #SD)-1), #sd))
SET #LD = (DATEADD(dd, -1*(Datepart(dd, #ED)-1), #ED))
SET #Mct = DATEDIFF(mm, #FD, #LD)
CREATE TABLE #MyTempTable (FoM smalldatetime, Trials int, Sales money)
WHILE #currct <= #Mct
BEGIN
INSERT INTO #MyTempTable (FoM, Trials, Sales)
VALUES
(DATEADD(MM, #currct, #FD), 0, 0)
SET #currct = #currct + 1
END
SELECT * FROM #MyTempTable
DROP TABLE #MyTempTable
For SQL Server 2000, this stackoverflow post looks promising for a way to temporarily generate dates calculated off of a start and end date. It's not exactly the same but quite similar. This post has a very in-depth answer on truncating dates, if needed.
In case anyone stumbles on this question and is working in PostgreSQL instead of SQL Server 2000, here is how you might do it there...
PostgreSQL has a nifty series generating function. For your example, you could use this series of all days instead of generating an entire calendar table, and then do groupings and matchups from there.
SELECT current_date + s.a AS dates FROM generate_series(0,14,7) AS s(a);
dates
------------
2004-02-05
2004-02-12
2004-02-19
(3 rows)
SELECT * FROM generate_series('2008-03-01 00:00'::timestamp,
'2008-03-04 12:00', '10 hours');
generate_series
---------------------
2008-03-01 00:00:00
2008-03-01 10:00:00
2008-03-01 20:00:00
2008-03-02 06:00:00
2008-03-02 16:00:00
2008-03-03 02:00:00
2008-03-03 12:00:00
2008-03-03 22:00:00
2008-03-04 08:00:00
(9 rows)
I would also look into date_trunc from PostgreSQL using 'month' for the truncator field to maybe refactor your original query to easily match with a date_trunc version of the calendar series.
select top (datediff(D,#start,#end)) dateadd(D,id-1,#start)
from BIG_TABLE_WITH_NO_JUMPS_IN_ID
declare #start datetime
set #start = '2016-09-01'
declare #end datetime
set #end = '2016-09-30'
create table #Date
(
table_id int identity(1,1) NOT NULL,
counterDate datetime NULL
);
insert into #Date select top (datediff(D,#start,#end)) NULL from SOME_TABLE
update #Date set counterDate = dateadd(D,table_id - 1, #start)
The code above should populate the table with all the dates between the start and end. You would then just join on this table to get all of the dates needed. If you only needed a certain day of each month, you could dateadd a month instead.
SELECT P.Id
, DATEADD ( DD, -P.Id, P.Date ) AS Date
FROM (SELECT TOP 1000 ROW_NUMBER () OVER (ORDER BY (SELECT NULL)) AS Id, CAST(GETDATE () AS DATE) AS Date FROM master.dbo.spt_values) AS P
This query returns a table calendar for the last 1000 days or so. It can be put in a temporary or other table.
Create a table variable containing a date for each month in a year:
declare #months table (reportMonth date, PRIMARY KEY (reportMonth));
declare #start date = '2018', #month int = 0; -- base 0 month
while (#month < 12)
begin
insert into #months select dateAdd(month, #month, #start);
select #month = #month + 1;
end
--verify
select * from #months;
This is by far the quickest method I have found (much quicker than inserting rows 1 by 1 in a WHILE loop):
DECLARE #startDate DATE = '1900-01-01'
DECLARE #endDate DATE = '2050-01-01'
SELECT DATEADD(DAY, sequenceNumber, #startDate) AS TheDate
INTO #TheDates
FROM (
SELECT ones.n + 10*tens.n + 100*hundreds.n + 1000*thousands.n + 10000*tenthousands.n AS sequenceNumber
FROM
(VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) ones(n),
(VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) tens(n),
(VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) hundreds(n),
(VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) thousands(n),
(VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) tenthousands(n)
WHERE ones.n + 10*tens.n + 100*hundreds.n + 1000*thousands.n + 10000*tenthousands.n <= DATEDIFF(day, #startDate, #endDate)
) theNumbers
SELECT *
FROM #TheDates
ORDER BY TheDate
The recursive answer:
DECLARE #startDate AS date = '20220315';
DECLARE #endDate AS date = '20230316'; -- inclusive
WITH cte_minutes(dt)
AS (
SELECT
DATEFROMPARTS(YEAR(#startDate), MONTH(#startDate), 1)
UNION ALL
SELECT
DATEADD(month, 1, dt)
FROM
cte_minutes
WHERE DATEADD(month, 1, dt) < #endDate
)
SELECT
dt
into #dates
FROM
cte_minutes
WHERE
dt >= #startDate
AND
dt <= #endDate
OPTION (MAXRECURSION 2000);
DROP TABLE dbo.#dates
What is a way to find gaps in a set of date spans?
For example, I have these date spans:
1/ 1/11 - 1/10/11
1/13/11 - 1/15/11
1/20/11 - 1/30/11
Then I have a start and end date of 1/7/11 and 1/14/11.
I want to be able to tell that between 1/10/11 and 1/13/11 there is a gap so the start and end date is not possible. Or I want to return only the datespans up to the first gap encountered.
If this can be done in SQL server that would be good.
I was thinking to go through each date to find out if it lands in a datespan... if it does not then there's a gap on that day.
Jump to 2nd last code block for: *I want to be able to tell that
between 1/10/11 and 1/13/11 there is
a gap so the start and end date is*
not possible.
Jump to last code block for: *I want to return only
the datespans up to the first gap
encountered.*
First of all, here's a virtual table to discuss
create table spans (date1 datetime, date2 datetime);
insert into spans select '20110101', '20110110';
insert into spans select '20110113', '20110115';
insert into spans select '20110120', '20110130';
This is a query that will list, individually, all the dates in the calendar
declare #startdate datetime, #enddate datetime
select #startdate = '20110107', #enddate = '20110114'
select distinct a.date1+v.number
from spans A
inner join master..spt_values v
on v.type='P' and v.number between 0 and datediff(d, a.date1, a.date2)
-- we don't care about spans that don't intersect with our range
where A.date1 <= #enddate
and #startdate <= A.date2
Armed with this query, we can now test to see if there are any gaps, by
counting the days in the calendar against the expected number of days
declare #startdate datetime, #enddate datetime
select #startdate = '20110107', #enddate = '20110114'
select case when count(distinct a.date1+v.number)
= datediff(d,#startdate, #enddate) + 1
then 'No gaps' else 'Gap' end
from spans A
inner join master..spt_values v
on v.type='P' and v.number between 0 and datediff(d, a.date1, a.date2)
-- we don't care about spans that don't intersect with our range
where A.date1 <= #enddate
and #startdate <= A.date2
-- count only those dates within our range
and a.date1 + v.number between #startdate and #enddate
Another way to do this is to just build the calendar from #start
to #end up front and look to see if there is a span with this date
declare #startdate datetime, #enddate datetime
select #startdate = '20110107', #enddate = '20110114'
-- startdate+v.number is a day on the calendar
select #startdate + v.number
from master..spt_values v
where v.type='P' and v.number between 0
and datediff(d, #startdate, #enddate)
-- run the part above this line alone to see the calendar
-- the condition checks for dates that are not in any span (gap)
and not exists (
select *
from spans
where #startdate + v.number between date1 and date2)
The query returns ALL dates that are gaps in the date range #start - #end
A TOP 1 can be added to just see if there are gaps
To return all records that are before the gap, use the query as a
derived table in a larger query
declare #startdate datetime, #enddate datetime
select #startdate = '20110107', #enddate = '20110114'
select *
from spans
where date1 <= #enddate and #startdate <= date2 -- overlaps
and date2 < ( -- before the gap
select top 1 #startdate + v.number
from master..spt_values v
where v.type='P' and v.number between 0
and datediff(d, #startdate, #enddate)
and not exists (
select *
from spans
where #startdate + v.number between date1 and date2)
order by 1 ASC
)
Assuming MySQL, something like this would work:
select #olddate := null;
select start_date, end_date, datediff(end_date, #olddate) as diff, #olddate:=enddate
from table
order by start_date asc, end_date asc
having diff > 1;
Basically: cache the previous row's end_date in the #olddate variable, and then do a diff on that "old" value with the currel enddate. THe having clause will return only the records where the difference between two rows is greater than a day.
disclaimer: Haven't tested this, but the basic query construct should work.
I want to be able to tell that between
1/10/11 and 1/13/11 there is a gap so
the start and end date is not
possible.
I think you're asking this question: does the data in your table have a gap between the start date and the end date?
I created a one-column table, date_span, and inserted your date spans into it.
You can identify a gap by counting the number of days between start date and end date, and comparing that the the number of rows in date_span for the same range.
select
date '2011-01-14' - date '2011-01-07' + 1 as elapsed_days,
count(*) from date_span
where cal_date between '2011-01-07' and '2011-01-14';
returns
elapsed_days count
-- --
8 6
Since they're not equal, there's a gap in the table "date_span" between 2011-01-07 and 2011-01-14. I'll stop there for now, because I'm really not certain what you're trying to do.