I am creating a query to give number of days between two days based on year. Actually I have below type of date range
From Date: TO_DATE('01-Jun-2011','dd-MM-yyyy')
To Date: TO_DATE('31-Dec-2013','dd-MM-yyyy')
My Result should be:
Year Number of day
------------------------------
2011 XXX
2012 XXX
2013 XXX
I've tried below query
WITH all_dates AS
(SELECT start_date + LEVEL - 1 AS a_date
FROM
(SELECT TO_DATE ('21/03/2011', 'DD/MM/YYYY') AS start_date ,
TO_DATE ('25/06/2013', 'DD/MM/YYYY') AS end_date
FROM dual
)
CONNECT BY LEVEL <= end_date + 1 - start_date
)
SELECT TO_CHAR ( TRUNC (a_date, 'YEAR') , 'YYYY' ) AS YEAR,
COUNT (*) AS num_days
FROM all_dates
WHERE a_date - TRUNC (a_date, 'IW') < 7
GROUP BY TRUNC (a_date, 'YEAR')
ORDER BY TRUNC (a_date, 'YEAR') ;
I got exact output
Year Number of day
------------------------------
2011 286
2012 366
2013 176
My question is if i use connect by then query execution takes long time as i have millions of records in table and hence i don't want to use connect by clause
connect by clause is creating virtual rows against the particular record.
Any help or suggestion would be greatly appreciated.
From your vague expected results I think you want the number of records between those dates, not the number of days; but it's rather unclear. Since you refer to a table in the question I assume you want something related to the table data, not simply days between two dates which wouldn't depend on a table at all. (I have no idea what the connect by clause reference means though). This should give you that, if it is what you want:
select extract(year from date_field), count(*)
from t42
where date_field >= to_date('01-Jun-2011', 'DD-MON-YYYY')
and date_field < to_date('31-Dec-2013') + interval '1' day
group by extract(year from date_field)
order by extract(year from date_field);
The where clause is as you'd expect between two dates; I've assumed there might be times in your date field (i.e. not all at midnight) and that you want to count all records on the last date in your range. Then it's grouping and counting based on the year for each record.
SQL Fiddle.
If you want the number of days that have records within the range, then you can just vary the count slightly:
select extract(year from date_field), count(distinct trunc(date_field))
...
SQL Fiddle.
you can use the below function to reduce the number of virtual rows by considering only the years in between.You can check the SQLFIDDLE to check the performance.
First consider only the number of days between start date and the year end of that year or
End date if it is in same year
Then consider the years in between from next year of start date to the year before the end date year
Finally consider the number of days from start of end date year to end date
Hence instead of iterating for all the days between start date and end date we need to iterate only the years
WITH all_dates AS
(SELECT (TO_CHAR(START_DATE,'yyyy') + LEVEL - 1) YEARS_BETWEEN,start_date,end_date
FROM
(SELECT TO_DATE ('21/03/2011', 'DD/MM/YYYY') AS start_date ,
TO_DATE ('25/06/2013', 'DD/MM/YYYY') AS end_date
FROM dual
)
CONNECT BY LEVEL <= (TO_CHAR(end_date,'yyyy')) - (TO_CHAR(start_date,'yyyy')-1)
)
SELECT DECODE(TO_CHAR(END_DATE,'yyyy'),YEARS_BETWEEN,END_DATE
,to_date('31-12-'||years_between,'dd-mm-yyyy'))
- DECODE(TO_CHAR(START_DATE,'yyyy'),YEARS_BETWEEN,START_DATE
,to_date('01-01-'||years_between,'dd-mm-yyyy'))+1,years_between
FROM ALL_DATES;
In Oracle you can perform Addition and Substraction to dates like this...
SELECT
TO_DATE('31-Dec-2013','dd-MM-yyyy') - TO_DATE('01-Jun-2011','dd-MM-yyyy')
DAYS FROM DUAL;
it will return day difference between two dates....
select to_date(2011, 'yyyy'), to_date(2012, 'yyyy'), to_date(2013, 'yyyy')
from dual;
TO_DATE(2011,'Y TO_DATE(2012,'Y TO_DATE(2013,'Y
--------------- --------------- ---------------
01-MAY-11 01-MAY-12 01-MAY-13
select to_char(date_field,'yyyy'), count(*)
from your_table
where date_field between to_date('01-Jun-2011', 'DD-MON-YYYY')
and to_date('31-Dec-2013 23:59:59', 'DD-MON-YYYY hh24:mi:ss')
group by to_char(date_field,'yyyy')
order by to_char(date_field,'yyyy');
Related
I run this query in MSSQL to get the items, grouping by the last 7 days of the week:
SELECT COUNT(Date_Entered), DATENAME(WEEKDAY, Date_Entered)
FROM my_table
WHERE Board_Name = 'Board'
AND DATEDIFF(DAY,Date_Entered,GETDATE()) <= 7
GROUP BY DATENAME(WEEKDAY, Date_Entered)
In the result, days of the week are sorted in alphabetical order: Friday > Monday > Saturday > Sunday > Thursday > Tuesday > Wednesday
How do I sort by the normal/correct/common sense order, starting with the weekday of 7 days ago and ending with yesterday?
Ordering by MAX(Date_Entered) should work too:
SELECT
COUNT(Date_Entered),
DATENAME(WEEKDAY, Date_Entered)
FROM my_table
WHERE Board_Name = 'Board' AND DATEDIFF(DAY,Date_Entered,GETDATE()) <= 7
GROUP BY DATENAME(WEEKDAY, Date_Entered)
ORDER BY MAX(Date_Entered);
Normally you would want to order by the date ascending, but since you use an aggregate function you would need to group by the date which would ruin it, but since the max(date) in every group is the date you can do max(date) to order.
DATEPART is your friend, try it like this:
SELECT COUNT(Date_Entered), DATENAME(WEEKDAY, Date_Entered),DATEPART(WEEKDAY,Date_Entered)
FROM my_table
WHERE Board_Name = 'Board'
AND DATEDIFF(DAY,Date_Entered,GETDATE()) <= 7
GROUP BY DATEPART(WEEKDAY,Date_Entered),DATENAME(WEEKDAY, Date_Entered)
ORDER BY DATEPART(WEEKDAY,Date_Entered)
If you can't count on data being available for every week then you'd need to do something more based on date calculations. Off the top of my head I think this will be more reliable:
ORDER BY (DATEDIFF(dd, MAX(Date_Entered), CURRENT_TIMESTAMP) + 77777) % 7
EDIT: I wrote that not realizing that the data was already limited to a single week. I thought the intention was to group in buckets by day of week for a longer range of dates.
I'll also comment that to me it is more natural to do the grouping on cast(Date_Entered as date) rather than on a string value and I wouldn't be surprised if it's a more efficient query.
I have a table in MSSQL with the following structure:
PersonId
StartDate
EndDate
I need to be able to show the number of distinct people in the table within a date range or at a given date.
As an example i need to show on a daily basis the totals per day, e.g. if we have 2 entries on the 1st June, 3 on the 2nd June and 1 on the 3rd June the system should show the following result:
1st June: 2
2nd June: 5
3rd June: 6
If however e.g. on of the entries on the 2nd June also has an end date that is 2nd June then the 3rd June result would show just 5.
Would someone be able to assist with this.
Thanks
UPDATE
This is what i have so far which seems to work. Is there a better solution though as my solution only gets me employed figures. I also need unemployed on another column - unemployed would mean either no entry in the table or date not between and no other entry as employed.
CREATE TABLE #Temp(CountTotal int NOT NULL, CountDate datetime NOT NULL);
DECLARE #StartDT DATETIME
SET #StartDT = '2015-01-01 00:00:00'
WHILE #StartDT < '2015-08-31 00:00:00'
BEGIN
INSERT INTO #Temp(CountTotal, CountDate)
SELECT COUNT(DISTINCT PERSON.Id) AS CountTotal, #StartDT AS CountDate FROM PERSON
INNER JOIN DATA_INPUT_CHANGE_LOG ON PERSON.DataInputTypeId = DATA_INPUT_CHANGE_LOG.DataInputTypeId AND PERSON.Id = DATA_INPUT_CHANGE_LOG.DataItemId
LEFT OUTER JOIN PERSON_EMPLOYMENT ON PERSON.Id = PERSON_EMPLOYMENT.PersonId
WHERE PERSON.Id > 0 AND DATA_INPUT_CHANGE_LOG.Hidden = '0' AND DATA_INPUT_CHANGE_LOG.Approved = '1'
AND ((PERSON_EMPLOYMENT.StartDate <= DATEADD(MONTH,1,#StartDT) AND PERSON_EMPLOYMENT.EndDate IS NULL)
OR (#StartDT BETWEEN PERSON_EMPLOYMENT.StartDate AND PERSON_EMPLOYMENT.EndDate) AND PERSON_EMPLOYMENT.EndDate IS NOT NULL)
SET #StartDT = DATEADD(MONTH,1,#StartDT)
END
select * from #Temp
drop TABLE #Temp
You can use the following query. The cte part is to generate a set of serial dates between the start date and end date.
DECLARE #ViewStartDate DATETIME
DECLARE #ViewEndDate DATETIME
SET #ViewStartDate = '2015-01-01 00:00:00.000';
SET #ViewEndDate = '2015-02-25 00:00:00.000';
;WITH Dates([Date])
AS
(
SELECT #ViewStartDate
UNION ALL
SELECT DATEADD(DAY, 1,Date)
FROM Dates
WHERE DATEADD(DAY, 1,Date) <= #ViewEndDate
)
SELECT [Date], COUNT(*)
FROM Dates
LEFT JOIN PersonData ON Dates.Date >= PersonData.StartDate
AND Dates.Date <= PersonData.EndDate
GROUP By [Date]
Replace the PersonData with your table name
If startdate and enddate columns can be null, then you need to add
addditional conditions to the join
It assumes one person has only one record in the same date range
You could do this by creating data where every start date is a +1 event and end date is -1 and then calculate a running total on top of that.
For example if your data is something like this
PersonId StartDate EndDate
1 20150101 20150201
2 20150102 20150115
3 20150101
You first create a data set that looks like this:
EventDate ChangeValue
20150101 +2
20150102 +1
20150115 -1
20150201 -1
And if you use running total, you'll get this:
EventDate Total
2015-01-01 2
2015-01-02 3
2015-01-15 2
2015-02-01 1
You can get it with something like this:
select
p.eventdate,
sum(p.changevalue) over (order by p.eventdate asc) as total
from
(
select startdate as eventdate, sum(1) as changevalue from personnel group by startdate
union all
select enddate, sum(-1) from personnel where enddate is not null group by enddate
) p
order by p.eventdate asc
Having window function with sum() requires SQL Server 2012. If you're using older version, you can check other options for running totals.
My example in SQL Fiddle
If you have dates that don't have any events and you need to show those too, then the best option is probably to create a separate table of dates for the whole range you'll ever need, for example 1.1.2000 - 31.12.2099.
-- Edit --
To get count for a specific day, it's possible use the same logic, but just sum everything up to that day:
declare #eventdate date
set #eventdate = '20150117'
select
sum(p.changevalue)
from
(
select startdate as eventdate, 1 as changevalue from personnel
where startdate <= #eventdate
union all
select enddate, -1 from personnel
where enddate < #eventdate
) p
Hopefully this is ok, can't test since SQL Fiddle seems to be unavailable.
Im trying to go to a particular date after finding a "start date"
Eg. I have the column start_date "01-OCT-2014" but now after getting the year "2014" from this data I want to create a column called "fin_yr" which should add +1 to the year and show the date "01-Jul-2015"
another eg:
start_date "23-APR-2013" then a new column called "fin_yr" should have the value "01-Jul-2014"
thanks a ton (Netezza answers please)
The following will work in a Netezza environment, using the extract function ( date_part would have worked just as well) to add one to the year, and set the month and day to July 1st.
SELECT start_date,
to_date(extract(YEAR FROM start_date) +1 || '0701', 'YYYYMMDD') fin_year
FROM (
SELECT CURRENT_DATE start_date
)
foo;
START_DATE | FIN_YEAR
------------+------------
2015-04-28 | 2016-07-01
(1 row)
if you column name is "dt" then you can add 1 year by doing this:
SELECT DATEADD(year, 1, dt)
FROM foo
I don't understand how you go from 23-APR-2013 to 01-Jul-2014 though. That's adding 1 year + some number of days. If for example you want to add 1 year + 99 days you could do something like:
SELECT DATEADD(day, 99, DATEADD(year, 1, dt))
FROM foo
I have a table of instances that have a Start Date and an End Date column. Here is a simple example:
ID StartDate EndDate
1 1/8/2015 1/10/2015
2 1/8/2015 1/15/2015
3 2/6/2015 3/2/2015
4 1/6/2015 2/20/2015
5 3/18/2015 4/2/2015
I'm trying to write a query to find out how many unique days occur for a given month, but some of the instances overlap and span multiple months which is making it difficult. The results I want would look something like this:
Month # of days
January 26 (earliest is ID 4 starting 1/6)
February 28 (entire month because of ID 3 and 4)
March 16 (2 days from ID 3, 14 days from ID 5)
April 2 (first 2 days of the month from ID 5)
May 0
Any help would be greatly appreciated. Thanks!!
J,
Please check my SQL script below.
Before you run the script you will realize that I've used a SQL Dates table actually a SQL function which returns a temporary dates table.
You can find the source codes at given tutorial
I also used multiple CTE queries
;with dates as (
select
cast(date as date) date
from [dbo].[DateTable]('1/1/2015','12/31/2015')
), cte as (
select
distinct date
from instances, dates
where dates.date between instances.startdate and instances.enddate
)
select
year(date) year, month(date) month, count(*) dayscount
from cte
group by year(date), month(date)
By the way the March returns 16 days, 2 from one and 14 from other.
I hope the Select statement is useful,
The problem is too complicated;
In my opinion, you need to write a function that counts the number of "unique" days of ranges mentioned in the records.
I didn't write the function, but the design of this new function, "num", is like this:
1- It should get the month and year (named aMonth and aYear).
2- It Finds all records that have at least a day in aYear/aMonth:
(month(startDate)=aMonth and year(startDate)=aYear)
or
(month(endDate)=aMonth and year(endDate)=aYear)
or
(
((month(startDate)<aMonth and year(startDate)=aYear) or (year(startDate)<aYear))
and
((month(endDate)>aMonth and year(endDate)=aYear) or (year(endDate)>aYear))
)
3- Over these records, it should open a cursor, and process the records one by one.
4- While processing each records of the cursor, you can count the days of the month and store them in an array (or 28-31 character string of 0/1, for example).
5- count the number of 1's of this array (or string) and return it.
Having written this function ("num"), The high level of the answer will be like this:
Select 'January', dbo.num(1, 2015) as days
union all
Select 'February', dbo.num(2, 2015) as days
union all
Select 'March', dbo.num(3, 2015) as days
union all
Select 'April', dbo.num(4, 2015) as days
union all
Select 'May', dbo.num(5, 2015) as days
union all
Select 'June', dbo.num(6, 2015) as days
union all
Select 'July', dbo.num(7, 2015) as days
union all
Select 'August', dbo.num(8, 2015) as days
union all
Select 'September', dbo.num(9, 2015) as days
union all
Select 'October', dbo.num(10, 2015) as days
union all
Select 'November', dbo.num(11, 2015) as days
union all
Select 'December', dbo.num(12, 2015) as days
If you count the days for the same year only, you can try this. I only build the code for two months but it's easy to extend it.
SELECT
(SELECT SUM(CASE WHEN sdate>='2015-2-1' OR edate<'2015-1-1' THEN 0
WHEN edate>='2015-2-1' THEN datediff(day, sdate, '2015-2-1')
ELSE datediff(day,sdate,edate) END)
FROM a1)
AS Jan_Days,
(SELECT SUM(CASE WHEN sdate>='2015-3-1' OR edate<'2015-2-1' THEN 0
WHEN edate>='2015-3-1' THEN datediff(day, sdate, '2015-3-1')
ELSE datediff(day,sdate,edate) END)
from a1 )
AS Feb_Days,
...
It's far from efficient. It will be more efficient to use a script or stored procedure running through your records and calculate the results.
Hy. There are employee records in my postgresql database something like
CODE DATE COUNT
"3443" "2009-04-02" 3
"3444" "2009-04-06" 1
"3443" "2009-04-06" 1
"3443" "2009-04-07" 7
I want to use a query "SELECT ALL CODES AND COUNT THEM THAT OCCURRED IN THE MONTH"
RESULT:
CODE DATE COUNT
"3443" "2009-04" 3
"3441" "2009-04" 13
"3442" "2009-04" 11
"3445" "2009-04" 72
I did use a query i.e.
SELECT CODE,date_part('month',DATE),count(CODE)
FROM employee
where
group by CODE,DATE
The above query runs fine but the months listed in the records are in form of numbers and its hard to find that a month belongs to which year. In short I want to get the result just like mention above in the RESULT section. Thanks
Try this:
SELECT CODE, to_char(DATE, 'YYYY-MM'), count(CODE)
FROM employee
where
group by CODE, to_char(DATE, 'YYYY-MM')
Depending on whether you want the result as text or a date, you can also write it like this:
SELECT CODE, date_trunc('month', DATE), COUNT(*)
FROM employee
GROUP BY CODE, date_trunc('month', DATE);
Which in your example would return this, with DATE still a timestamp, which can be useful if you are going to do further calculations on it since no conversions are necessary:
CODE DATE COUNT
"3443" "2009-04-01" 3
"3441" "2009-04-01" 13
"3442" "2009-04-01" 11
"3445" "2009-04-01" 72
date_trunc() also accepts other values, for instance quarter, year etc.
See the documentation for all values
Try any of
SELECT CODE,count(CODE),
DATE as date_normal,
date_part('year', DATE) as year,
date_part('month', DATE) as month,
to_timestamp(
date_part('year', DATE)::text
|| date_part('month', DATE)::text, 'YYYYMM')
as date_month
FROM employee
where
group by CODE,DATE;