Sales counts by week for individual items sold - sql

I have a large SQL table that contains, among other fields, the following
Item, Date Sold,
1 Day Coaster 2014-11-10,
3 Day Coaster 2014-02-16,
1 Day Coaster 2014-11-11,
AC-Zip 2014-12-21,
5 Day Package 2014-05-15,
1 Day Coaster 2014-11-07,
Being new to SQL, my expertise can only select the items individually and take the counts from individual results and type them into excel from the rows affected result.
I need to be able to pull the count of individual items sold by week and list the counts by week into an excel spreadsheet thus;
Week Item Count
2014-11-07-2014-11-13 1 Day Coaster 3

You need to use a Group BY statement.
here is a sample SQLFiddle, it might get you started: SQL Fiddle

You can use this :
SELECT A.Item,A.DateRange,COUNT(A.Item)
FROM (
SELECT Item,
(SELECT DISTINCT
CASE
WHEN YEAR(DATEADD(DAY, 1-DATEPART(WEEKDAY, Min(Date_Sold)), Min(Date_Sold))) < YEAR(Min(Date_Sold))
THEN
CAST(DATEADD(YEAR, DATEDIFF(YEAR, 0,DATEADD(YEAR, 0 ,GETDATE())), 0) AS Varchar(50))
+ ' TO ' + Cast(DATEADD(dd, 7-(DATEPART(dw, Min(Date_Sold))), Min(Date_Sold)) AS Varchar(50))
ELSE
Cast(DATEADD(DAY, 1-DATEPART(WEEKDAY, Min(Date_Sold)), Min(Date_Sold)) AS Varchar(50))
+ ' TO ' + Cast(DATEADD(dd, 7-(DATEPART(dw, Min(Date_Sold))), Min(Date_Sold)) AS Varchar(50))
END AS DateRange
FROM <YOUR_TABLE> B
WHERE A.Date_Sold=B.Date_Sold
AND A.Item=B.Item
group by Item
) AS DateRange
FROM <YOUR_TABLE> A
) A
GROUP BY Item,DateRange;
Let me know if this is not what you are looking at.

USe this. Fiddler Demo
Output:
Query
CREATE TABLE weekdays
(
datevalue datetime NOT NULL
, Item VARCHAR(MAX)
);
INSERT INTO weekdays (datevalue, item) VALUES
('2014-11-10', '1 Day Coaster'),
('2014-02-16', '2 Day Coaster'),
('2014-11-11', '1 Day Coaster'),
('2014-12-21', 'AC-Zip'),
('2014-05-15', '5 Day Package'),
('2014-11-07', '1 Day Coaster');
CREATE FUNCTION [dbo].[ufn_GetFirstDayOfWeek]
( #pInputDate DATETIME )
RETURNS DATETIME
BEGIN
SET #pInputDate = CONVERT(VARCHAR(10), #pInputDate, 111)
RETURN DATEADD(DD, 1 - DATEPART(DW, #pInputDate),
#pInputDate)
END
GO
SET DATEFIRST 5
SELECT CONVERT(VARCHAR(10), A.Date, 101) + ' - ' +
CONVERT(VARCHAR(10), DATEADD(d, 6, A.Date), 101) AS Week,
A.Item,
COUNT(A.Item) AS COUNT FROM
(SELECT [dbo].ufn_GetFirstDayOfWeek(datevalue) AS Date, item FROM weekdays) AS A
GROUP BY A.Date, A.Item

Related

SQL Server: whole weeks total in a calendar month

I want weekly totals in a month. It will not include any partial week or future weeks. Week starts from Monday to Sunday.
I have a table structure like
Date Value -- Comments
----------------------------------------------------------------------
2016-10-01 7 Ignore this because its not a whole week in a month
2016-10-05 8 Week 1
2016-10-07 5 Week 1
2016-10-11 2 Week 2
2016-10-15 1 Week 2
2016-10-17 9 Ignore this because the week is not finished yet
OUTPUT
WeekNo Total
41 13
42 3
The easier way would be to build a Tally "date" table.
you can generate it from any Tally Table like:
DECLARE #StartDate DATE = '20160101'
, #EndDate DATE = '20161231';
WITH cte AS (
SELECT DATEADD(DAY, n - 1, #StartDate) AS date
FROM tally
WHERE n - 1 <= DATEDIFF(DAY, #StartDate, #EndDate)
)
SELECT
c.date
,YEAR(c.date) AS Year
,MONTH(c.date) AS Month
,DAY(c.date) AS Month
,DATEPART(WEEK,c.date) AS Week
,CASE WHEN 7<>COUNT(c.date) OVER (PARTITION BY YEAR(c.date),MONTH(c.date),DATEPART(WEEK,c.date)) THEN 0 ELSE 1 END AS isFullWeek
FROM cte c
Then you just need to Join it to what ever query you need.
DECLARE #StartDate datetime = '2011-10-01';
DECLARE #EndDate datetime = '2016-10-31';
SELECT
CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 2, tblData.RecordDate) AS date) AS WeekStart,
CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 8, tblData.RecordDate) AS date) AS WeekEnd,
SUM(Value) AS Total
FROM tblData
WHERE (#StartDate IS NULL
OR CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 2, tblData.RecordDate) AS date) >= CAST(#StartDate AS date))
AND (#EndDate IS NULL
OR CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 8, tblData.RecordDate) AS date) <= CAST(#EndDate AS date))
AND CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 8, tblData.RecordDate) AS date) < CAST(GETDATE() AS date)
GROUP BY CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 2, tblData.RecordDate) AS date),
CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 8, tblData.RecordDate) AS date)
Create a calendar table that meets your request, like this:
create table calendarTable ([date] date, weekNro int)
go
insert into calendarTable
select dateadd(d,n,'20160101'), DATEPART(WK,dateadd(d,n,'20151231'))
from numbers where n<500
If you don't have a Numbers Table, you must create it first. like this
SET NOCOUNT ON
CREATE TABLE Numbers (n bigint PRIMARY KEY)
GO
DECLARE #numbers table(number int);
WITH numbers(number) as (
SELECT 1 AS number
UNION all
SELECT number+1 FROM numbers WHERE number<10000
)
INSERT INTO #numbers(number)
SELECT number FROM numbers OPTION(maxrecursion 10000)
INSERT INTO Numbers(n) SELECT number FROM #numbers
Then query your table joining calendar table having in mind actual date for completed week, like this:
Similar to #Kilren but translated into postgres and using generate series from https://stackoverflow.com/a/11391987/10087503 to generate the dates
DECLARE #StartDate DATE = '20160101'
, #EndDate DATE = '20161231';
WITH cte AS (
SELECT i::date AS date FROM generate_series(#StartDate,
#EndDate, '1 day'::interval) i
)
SELECT
c.date
,DATE_TRUNC('month' ,c.date) AS month_trunc
,DATE_PART('week',c.date) AS week
,CASE WHEN 7<>COUNT(c.date)
OVER (PARTITION BY DATE_TRUNC('month' ,c.date),DATE_PART('week',c.date))
THEN 0 ELSE 1 END AS is_full_week
FROM cte c
Select DATEPART(ww, date) , SUM(Case When Comments Like '%1' then Value when Comments Like '%2' then Value else Value end)
from schema.tablename
group by DATEPART(ww,date)
I'm sorry if this doesn't work, it's the only way I thought to structure it.

SQL populate total working days per month minus bank holidays for current financial year

I am after a view which will look like my first attached picture however with right hand column populated and not blank. The logic is as follows:
The data must be for current financial period. Therfore April will be 2011 and March will be 2012 and so on.
The calculation for Days Available for the single months will be:
Total number of working days (Monday-Friday) minus any bank holidays that fall into that particular month, for that particular financial year (Which we have saved in a table - see second image).
Column names for holiday table left to right: holidaytypeid, name, holstart, holend.
Table name: holidaytable
To work out the cumulative months 'Days Available' it will be a case of summing already populated data for the single months. E.g April-May will be April and May's data SUMMED and so on and so forth.
I need the SQL query in perfect format so that this can be pasted straight in and will work (i.e with the correct column names and table names)
Thanks for looking.
DECLARE #StartDate DATETIME, #EndDate DATETIME
SELECT #StartDate = '01/04/2011',
#EndDate = '31/03/2012'
CREATE TABLE #Data (FirstDay DATETIME NOT NULL PRIMARY KEY, WorkingDays INT NOT NULL)
;WITH DaysCTE ([Date]) AS
( SELECT #StartDate
UNION ALL
SELECT DATEADD(DAY, 1, [Date])
FROM DaysCTE
WHERE [Date] <= #Enddate
)
INSERT INTO #Data
SELECT MIN([Date]),
COUNT(*) [Day]
FROM DaysCTE
LEFT JOIN HolidayTable
ON [Date] BETWEEN HolStart AND HolEnd
WHERE HolidayTypeID IS NULL
AND DATENAME(WEEKDAY, [Date]) NOT IN ('Saturday', 'Sunday')
GROUP BY DATEPART(MONTH, [Date]), DATEPART(YEAR, [Date])
OPTION (MAXRECURSION 366)
DECLARE #Date DATETIME
SET #Date = (SELECT MIN(FirstDay) FROM #Data)
SELECT Period,
WorkingDays [Days Available (Minus the Holidays)]
FROM ( SELECT DATENAME(MONTH, Firstday) [Period],
WorkingDays,
0 [SortField],
FirstDay
FROM #Data
UNION
SELECT DATENAME(MONTH, #Date) + ' - ' + DATENAME(MONTH, Firstday),
( SELECT SUM(WorkingDays)
FROM #Data b
WHERE b.FirstDay <= a.FirstDay
) [WorkingDays],
1 [SortField],
FirstDay
FROM #Data a
WHERE FirstDay > #Date
) data
ORDER BY SortField, FirstDay
DROP TABLE #Data
If you do this for more than 1 year you will need to change the line:
OPTION (MAXRECURSION 366)
Otherwise you'll get an error - The number needs to be higher than the number of days you are querying.
EDIT
I have just come accross this old answer of mine and really don't like it, there are so many things that I now consider bad practise, so am going to correct all the issues:
I did not terminate statements with a semi colon properly
Used a recursive CTE to generate a list of dates
Generate a set or sequence without loops – part 1
Generate a set or sequence without loops – part 2
Generate a set or sequence without loops – part 3
Did not include the column list for an insert
Used DATENAME to elimiate weekends, which is language specific, much better to explicitly set DATEFIRST and use DATEPART
Used LEFT JOIN/IS NULL instead of NOT EXISTS to elimiate records from the holiday table. In SQL Server LEFT JOIN/IS NULL is less efficient than NOT EXISTS
These are all minor things, but they are things I would critique (at least in my head if not outloud) when reviewing someone else's query, so can't really not correct my own work! Rewriting the query would give.
SET DATEFIRST 1;
DECLARE #StartDate DATETIME = '20110401',
#EndDate DATETIME = '20120331';
CREATE TABLE #Data (FirstDay DATETIME NOT NULL PRIMARY KEY, WorkingDays INT NOT NULL);
WITH DaysCTE ([Date]) AS
( SELECT TOP (DATEDIFF(DAY, #StartDate, #EndDate) + 1)
DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY a.object_id) - 1, #StartDate)
FROM sys.all_objects a
)
INSERT INTO #Data (FirstDay, WorkingDays)
SELECT FirstDay = MIN([Date]),
WorkingDays = COUNT(*)
FROM DaysCTE d
WHERE DATEPART(WEEKDAY, [Date]) NOT IN (6, 7)
AND NOT EXISTS
( SELECT 1
FROM dbo.HolidayTable ht
WHERE d.[Date] BETWEEN ht.HolStart AND ht.HolEnd
)
GROUP BY DATEPART(MONTH, [Date]), DATEPART(YEAR, [Date]);
DECLARE #Date DATETIME = (SELECT MIN(FirstDay) FROM #Data);
SELECT Period,
[Days Available (Minus the Holidays)] = WorkingDays
FROM ( SELECT DATENAME(MONTH, Firstday) [Period],
WorkingDays,
0 [SortField],
FirstDay
FROM #Data
UNION
SELECT DATENAME(MONTH, #Date) + ' - ' + DATENAME(MONTH, Firstday),
( SELECT SUM(WorkingDays)
FROM #Data b
WHERE b.FirstDay <= a.FirstDay
) [WorkingDays],
1 [SortField],
FirstDay
FROM #Data a
WHERE FirstDay > #Date
) data
ORDER BY SortField, FirstDay;
DROP TABLE #Data;
As a final point, this query becomes much simpler with a calendar table that stores all dates, and has flags for working days, holidays etc, rather than using a holiday table that just stores holidays.
Let me add few cents to this post. Just got assignment to calculate difference between planned hours and actual hour. The code below was converted to a function. So far no issue with the logic:
declare #date datetime = '11/07/2012'
declare #t table (HolidayID int IDENTITY(1,1) primary key,
HolidayYear int,
HolidayName varchar(50),
HolidayDate datetime)
INSERT #t
VALUES(2012, 'New Years Day', '01/02/2012'),
(2012,'Martin Luther King Day', '01/16/2012'),
(2012,'Presidents Day', '02/20/2012'),
(2012,'Memorial Day', '05/28/2012'),
(2012,'Independence Day', '07/04/2012'),
(2012,'Labor Day', '09/03/2012'),
(2012,'Thanksgiving Day', '11/22/2012'),
(2012,'Day After Thanksgiving', '11/23/2012'),
(2012,'Christmas Eve', '12/24/2012'),
(2012,'Christmas Day', '12/25/2012'),
(2013, 'New Years Day', '01/01/2013'),
(2013,'Martin Luther King Day', '01/21/2013'),
(2013,'Presidents Day', '02/18/2013'),
(2013,'Good Friday', '03/29/2013'),
(2013,'Memorial Day', '05/27/2013'),
(2013,'Independence Day', '07/04/2013'),
(2013,'Day After Independence Day', '07/05/2013'),
(2013,'Labor Day', '09/02/2013'),
(2013,'Thanksgiving Day', '11/28/2013'),
(2013,'Day After Thanksgiving', '11/29/2013'),
(2013,'Christmas Eve', NULL),
(2013,'Christmas Day', '12/25/2013')
DECLARE #START_DATE DATETIME,
#END_DATE DATETIME,
#Days int
SELECT #START_DATE = DATEADD(MONTH, DATEDIFF(MONTH, 0, #date), 0)
SELECT #END_DATE = DATEADD(month, 1,#START_DATE)
;WITH CTE AS
(
SELECT DATEADD(DAY, number, (DATEADD(MONTH, DATEDIFF(MONTH, 0, #date), 0) )) CDate
FROM master.dbo.spt_values where type = 'p' and number between 0 and 365
EXCEPT
SELECT HolidayDate FROM #t WHERE HolidayYear = YEAR(#START_DATE)
)
SELECT #Days = COUNT(CDate) --, datepart(dw, CDate) WDay
FROM CTE
WHERE (CDate >=#START_DATE and CDate < #END_DATE) AND DATEPART(dw, CDate) NOT IN(1,7)
SELECT #Days

Getting Number of weeks in a Month from a Datetime Column

I have a table called FcData and the data looks like:
Op_Date
2011-02-14 11:53:40.000
2011-02-17 16:02:19.000
2010-02-14 12:53:40.000
2010-02-17 14:02:19.000
I am looking to get the Number of weeks in That Month from Op_Date. So I am looking for output like:
Op_Date Number of Weeks
2011-02-14 11:53:40.000 5
2011-02-17 16:02:19.000 5
2010-02-14 12:53:40.000 5
2010-02-17 14:02:19.000 5
This page has some good functions to figure out the last day of any given month: http://www.sql-server-helper.com/functions/get-last-day-of-month.aspx
Just wrap the output of that function with a DATEPART(wk, last_day_of_month) call. Combining it with an equivalent call for the 1st-day-of-week will let you get the number of weeks in that month.
Use this to get the number of week for ONE specific date. Replace GetDate() by your date:
declare #dt date = cast(GetDate() as date);
declare #dtstart date = DATEADD(day, -DATEPART(day, #dt) + 1, #dt);
declare #dtend date = dateadd(DAY, -1, DATEADD(MONTH, 1, #dtstart));
WITH dates AS (
SELECT #dtstart ADate
UNION ALL
SELECT DATEADD(day, 1, t.ADate)
FROM dates t
WHERE DATEADD(day, 1, t.ADate) <= #dtend
)
SELECT top 1 DatePart(WEEKDAY, ADate) weekday, COUNT(*) weeks
FROM dates d
group by DatePart(WEEKDAY, ADate)
order by 2 desc
Explained: the CTE creates a result set with all dates for the month of the given date. Then we query the result set, grouping by week day and count the number of occurrences. The max number will give us how many weeks the month overlaps (premise: if the month has 5 Mondays, it will cover five weeks of the year).
Update
Now, if you have multiple dates, you should tweak accordingly, joining your query with the dates CTE.
Here is my take on it, might have missed something.
In Linq:
from u in TblUsers
let date = u.CreateDate.Value
let firstDay = new DateTime(date.Year, date.Month, 1)
let lastDay = firstDay.AddMonths(1)
where u.CreateDate.HasValue
select Math.Ceiling((lastDay - firstDay).TotalDays / 7)
And generated SQL:
-- Region Parameters
DECLARE #p0 Int = 1
DECLARE #p1 Int = 1
DECLARE #p2 Float = 7
-- EndRegion
SELECT CEILING(((CONVERT(Float,CONVERT(BigInt,(((CONVERT(BigInt,DATEDIFF(DAY, [t3].[value], [t3].[value2]))) * 86400000) + DATEDIFF(MILLISECOND, DATEADD(DAY, DATEDIFF(DAY, [t3].[value], [t3].[value2]), [t3].[value]), [t3].[value2])) * 10000))) / 864000000000) / #p2) AS [value]
FROM (
SELECT [t2].[createDate], [t2].[value], DATEADD(MONTH, #p1, [t2].[value]) AS [value2]
FROM (
SELECT [t1].[createDate], CONVERT(DATETIME, CONVERT(NCHAR(2), DATEPART(Month, [t1].[value])) + ('/' + (CONVERT(NCHAR(2), #p0) + ('/' + CONVERT(NCHAR(4), DATEPART(Year, [t1].[value]))))), 101) AS [value]
FROM (
SELECT [t0].[createDate], [t0].[createDate] AS [value]
FROM [tblUser] AS [t0]
) AS [t1]
) AS [t2]
) AS [t3]
WHERE [t3].[createDate] IS NOT NULL
According to this MSDN article: http://msdn.microsoft.com/en-us/library/ms174420.aspx you can only get the current week in the year, not what that month returns.
There may be various approaches to implementing the idea suggested by #Marc B. Here's one, where no UDFs are used but the first and the last days of month are calculated directly:
WITH SampleData AS (
SELECT CAST('20110214' AS datetime) AS Op_Date
UNION ALL SELECT '20110217'
UNION ALL SELECT '20100214'
UNION ALL SELECT '20100217'
UNION ALL SELECT '20090214'
UNION ALL SELECT '20090217'
),
MonthStarts AS (
SELECT
Op_Date,
MonthStart = DATEADD(DAY, 1 - DAY(Op_Date), Op_Date)
/* alternatively: DATEADD(MONTH, DATEDIFF(MONTH, 0, Op_Date), 0) */
FROM FcData
),
Months AS (
SELECT
Op_Date,
MonthStart,
MonthEnd = DATEADD(DAY, -1, DATEADD(MONTH, 1, MonthStart))
FROM FcData
)
Weeks AS (
SELECT
Op_Date,
StartWeek = DATEPART(WEEK, MonthStart),
EndWeek = DATEPART(WEEK, MonthEnd)
FROM MonthStarts
)
SELECT
Op_Date,
NumberOfWeeks = EndWeek - StartWeek + 1
FROM Weeks
All calculations could be done in one SELECT, but I chose to split them into steps and place every step in a separate CTE so it could be seen better how the end result was obtained.
You can get number of weeks per month using the following method.
Datepart(WEEK,
DATEADD(DAY,
-1,
DATEADD(MONTH,
1,
DATEADD(DAY,
1 - DAY(GETDATE()),
GETDATE())))
-
DATEADD(DAY,
1 - DAY(GETDATE()),
GETDATE())
+1
)
Here how you can get accurate amount of weeks:
DECLARE #date DATETIME
SET #date = GETDATE()
SELECT ROUND(cast(datediff(day, dateadd(day, 1-day(#date), #date), dateadd(month, 1, dateadd(day, 1-day(#date), #date))) AS FLOAT) / 7, 2)
With this code for Sep 2014 you'll get 4.29 which is actually true since there're 4 full weeks and 2 more days.

How I can select / sort dates by period intervals?

For ex:
If we have in table records like:
25/06/2009
28/12/2009
19/02/2010
16/04/2011
20/05/2012
I want to split/select this dates according to 6 month intervals starting from current date.
result should be like:
0-6 month from now: first record
7-12 month from now: second record
...
It will be much apreciated if you make this simple as I made it very stupid and complicated like:
declare variable like t1=curdate()+6
t2=curdate()+12
...
then selected records to fit between curdate() and t1, then t1 and t2 etc.
Thanks,
r.
CORRECTION: Had it backwards, Need to use Modulus, not integer division - sorry...
If MonthCount is a calculated value which counts the number of months since a specific Dec 31, and mod is modulus division (output the remainder after dividing)
Select [Column list here]
From Table
Group By Case When MonthCount Mod 12 < 6
Then 0 Else 1 End
In SQL Server, for example, you could use the DateDiff Function
Select [Column list here]
From Table
Group By Case When DateDiff(month, myDateColumn, curdate) % 12 < 6
Then 0 Else 1 End
( in SQL Server the percent sign is the modulus operator )
This will group all the record into buckets which each contain six months of data
SELECT (DATEDIFF(MONTH, thedate, GETDATE()) / 6) AS semester,
SUM(receipt)
FROM thetable
GROUP BY semester
ORDER BY semester
the key idea is grouping and ordering by the expression that gives you the "semester".
This question really baffled me, cos I couldn't actually come up with a simple solution for it. Damn.
Best I could manage was an absolute bastardization of the following where you create a Temp Table, insert the "Periods" into it, join back to your original table, and group off that.
Assume your content table has the following
ID int
Date DateTime
Counter int
And you're trying to sum all the counter's in six month periods
DECLARE #min_date datetime
select #min_date = min(date) from test
DECLARE #max_date datetime
select #max_date = max(date) from test
DECLARE #today_a datetime
DECLARE #today_b datetime
set #today_a = getdate()
set #today_b = getdate()
CREATE TABLE #temp (startdate DateTime, enddate DateTime)
WHILE #today_a > #min_date
BEGIN
INSERT INTO #temp (startDate, endDate) VALUES (dateadd(month, -6, #today_a), #today_a)
SET #today_a = dateadd(month, -6, #today_a)
END
WHILE #today_b < #max_date
BEGIN
INSERT INTO #temp (startDate, endDate) VALUES (#today_b, dateadd(month, 6, #today_b))
SET #today_b = dateadd(month, 6, #today_b)
END
SELECT * FROM #temp
SELECT
sum(counter),
'Between ' + Convert(nvarchar(10), startdate, 121) + ' => ' + Convert(nvarchar(10), enddate, 121) as Period
FROM test t
JOIN #Temp ht
ON t.Date between ht.startDate AND ht.EndDate
GROUP BY
'Between ' + Convert(nvarchar(10), startdate, 121) + ' => ' + Convert(nvarchar(10), enddate, 121)
DROP TABLE #temp
I really hope someone can come up with a better solution my brain has obviously melted.
Not quite what you're attempting to accomplish, but you could use the DATEDIFF function to distinguish the ranging of each record:
SELECT t.MonthGroup, SUM(t.Counter) AS TotalCount
FROM (
SELECT Counter, (DATEDIFF(m, GETDATE(), Date) / 6) AS MonthGroup
FROM Table
) t
GROUP BY t.MonthGroup
This would create a sub query with an expression that expresses the date ranging group you want. It would then group the sub-query by this date ranging group and you can then do whatever you want with the results.
Edit: I modified the example based on your example.
If you're using SQL Server:
SELECT *,
(
FLOOR
(
(
DATEDIFF(month, GETDATE(), date_column)
- CASE WHEN DAY(GETDATE()) > DAY(date_column) THEN 1 ELSE 0 END
) / 6.0
) * 6
) AS SixMonthlyInterval
FROM your_table
If you're using MySQL:
SELECT *,
(
FLOOR
(
(
((YEAR(date_column) - YEAR(CURDATE())) * 12)
+ MONTH(date_column) - MONTH(CURDATE())
- CASE WHEN DAY(CURDATE()) > DAY(date_column) THEN 1 ELSE 0 END
) / 6.0
) * 6
) AS SixMonthlyInterval
FROM your_table

Calculating in SQL the first working day of a given month

I have to calculate all the invoices which have been paid in the first 'N' days of a month. I have two tables
. INVOICE: it has the invoice information. The only field which does matter is called 'datePayment'
. HOLYDAYS: It is a one column table. Entries at this table are of the form "2009-01-01",
2009-05-01" and so on.
I should consider also Saturdays and Sundays
(this might be not a problem because I could insert those days at the Hollidays table in order to consider them as hollidays if neccesary)
The problem is to calculate which is the 'payment limit'.
select count(*) from invoice
where datePayment < PAYMENTLIMIT
My question is how to calculate this PAYMENTLIMIT. Where PAYMENTLIMIT is 'the fifth working day of every month'.
The query should be run under Mysql and Oracle therefore standard SQL should be used.
Any hint?
EDIT
In order to be consistent with the title of the question the pseudo-query should the read as follows:
select count(*) from invoice
where datePayment < FIRST_WORKING_DAY + N
then the question can be reduced to calculate the FIRST_WORKING_DAY of every month.
You could look for the first date in a month, where the date is not in the holiday table and the date is not a weekend:
select min(datePayment), datepart(mm, datePayment)
from invoices
where datepart(dw, datePayment) not in (1,7) --day of week
and not exists (select holiday from holidays where holiday = datePayment)
group by datepart(mm, datePayment) --monthnr
Something like this might work:
create function dbo.GetFirstWorkdayOfMonth(#Year INT, #Month INT)
returns DATETIME
as begin
declare #firstOfMonth VARCHAR(20)
SET #firstOfMonth = CAST(#Year AS VARCHAR(4)) + '-' + CAST(#Month AS VARCHAR) + '-01'
declare #currDate DATETIME
set #currDate = CAST(#firstOfMonth as DATETIME)
declare #weekday INT
set #weekday = DATEPART(weekday, #currdate)
-- 7 = saturday, 1 = sunday
while #weekday = 1 OR #weekday = 7
begin
set #currDate = DATEADD(DAY, 1, #currDate)
set #weekday = DATEPART(weekday, #currdate)
end
return #currdate
end
I'm not 100% sure about whether the "weekday" numbers are fixed or might depend on your locale on your SQL Server. Check it out!
Marc
Rather than a Holidays table of days to exclude, we use the calendar table approach: one row for every day the application will ever need (thirty years spans a modest 11K rows). So not only does it have an is_weekday column, it has other things relevant to the enterprise e.g. julianized_date. This way, every possible date would have a ready-prepared value for first_working_day_this_month and finding it involves a simple lookup (which SQL products tend to be optimized for!) rather than 'calculating' it each time on the fly.
We have dates table in our application (filled with all dates and date parts for some tens of years), what allows various "missing" date manipulations, like (in pseudo-sql):
select min(ourdates.datevalue)
from ourdates
where ourdates.year=<given year> and ourdates.month=<given month>
and ourdates.isworkday
and not exists (
select * from holidays
where holidays.datevalue=ourdates.datevalue
)
Ok, at a first stab, you could put the following code into a UDF and pass in the Year and Month as variables. It can then return TestDate which is the first working day of the month.
DECLARE #Month INT
DECLARE #Year INT
SELECT #Month = 5
SELECT #Year = 2009
DECLARE #FirstDate DATETIME
SELECT #FirstDate = CONVERT(varchar(4), #Year) + '-' + CONVERT(varchar(2), #Month) + '-' + '01 00:00:00.000'
DROP TABLE #HOLIDAYS
CREATE TABLE #HOLIDAYS (HOLIDAY DateTime)
INSERT INTO #HOLIDAYS VALUES('2009-01-01 00:00:00.000')
INSERT INTO #HOLIDAYS VALUES('2009-05-01 00:00:00.000')
DECLARE #DateFound BIT
SELECT #DateFound = 0
WHILE(#DateFound = 0)
BEGIN
IF(
DATEPART(dw, #FirstDate) = 1
OR
DATEPART(dw, #FirstDate) = 1
OR
EXISTS(SELECT * FROM #HOLIDAYS WHERE HOLIDAY = #FirstDate)
)
BEGIN
SET #FirstDate = DATEADD(dd, 1, #FirstDate)
END
ELSE
BEGIN
SET #DateFound = 1
END
END
SELECT #FirstDate
The things I don`t like with this solution though are, if your holidays table contains all days of the month there will be an infinite loop. (You could check the loop is still looking at the right month) It relies upon the dates being equal, eg all at time 00:00:00. Finally, the way I calculate the 1st of the month past in using string concatenation was a short cut. There are much better ways of finding the actual first day of the month.
Gets the first N working days of each month of year 2009:
select * from invoices as x
where
datePayment between '2009-01-01' and '2009-12-31'
and exists
(
select
1
from invoices
where
-- exclude holidays and sunday saturday...
(
datepart(dw, datePayment) not in (1,7) -- day of week
/*
-- Postgresql and Oracle have programmer-friendly IN clause
and
(datepart(yyyy,datePayment), datepart(mm,datePayment))
not in (select hyear, hday from holidays)
*/
-- this is the MSSQL equivalent of programmer-friendly IN
and
not exists
(
select * from holidays
where
hyear = datepart(yyyy,datePayment)
and hmonth = datepart(mm, datePayment)
)
)
-- ...exclude holidays and sunday saturday
-- get the month of x datePayment
and
(datepart(yyyy, datePayment) = datepart(yyyy, x.datePayment)
and datepart(mm, datePayment) = datepart(mm, x.datePayment))
group by
datepart(yyyy, datePayment), datepart(mm, datePayment)
having
x.datePayment < MIN(datePayment) + #N -- up to N working days
)
Returns the first Monday of the current month
SELECT DATEADD(
WEEK,
DATEDIFF( --x weeks between 1900-01-01 (Monday) and inner result
WEEK,
0, --1900-01-01
DATEADD( --inner result
DAY,
6 - DATEPART(DAY, GETDATE()),
GETDATE()
)
),
0 --1900-01-01 (Monday)
)
SELECT DATEADD(day, DATEDIFF (day, 0, DATEADD (month, DATEDIFF (month, 0, GETDATE()), 0) -1)/7*7 + 7, 0);
select if(weekday('yyyy-mm-01') < 5,'yyyy-mm-01',if(weekday('yyyy-mm-02') < 5,'yyyy-mm-02','yyyy-mm-03'))
Saturdays and Sundays are 5, 6 so you only need two checks to get the first working day