TSQL Finding Overlapping Hours - sql-server

When two tables are given
Employee Table
EmpID Name
1 Jon
2 Smith
3 Dana
4 Nancy
Lab Table
EmpID StartTime EndTime Date LabID
1 10:00 AM 12:15 PM 01/JAN/2000 Lab I
1 11:00 AM 14:15 PM 01/JAN/2000 Lab II
1 16:30 PM 18:30 PM 01/JAN/2000 Lab I
2 10:00 AM 12:10 PM 01/JAN/2000 Lab I
From the given details ,I have to find out the overlapping hours,and non overlapping hours of each employee on each date. (StartTime and EndTime are of type varchar).
The expected output is
-------------------------------------------------------------------------------
EmpID| Name| Overlapping | Non-Overlapping | Date
Period Period
-------------------------------------------------------------------------------
1 Jon | 10:00 AM to 12:15 PM |16:30 PM to 18:30 PM | 01/JAN/2000
| AND | |
| 11:00 AM to 14:15 PM | |
| AND ...(If any) | |
--------------------------------------------------------------------------------
2 Smith| NULL | 10:00 AM to 12:10 PM |01/JAN/2000
--------------------------------------------------------------------------------
Please help me to bring such output using TSQL(SQL Server 2005/2008).

First, you should probably consider using a DateTime field to store the StartTime and EndTime, and thus make calculations easier, and remove the need for the Date field.
SELECT t1.EmpID,
t1.StartTime,
t1.EndTime,
t2.StartTime
t2.EndTime,
FROM lab t1
LEFT OUTER JOIN lab t2
ON t2.StartTime BETWEEN t1.StartTime AND t1.EndTime
AND t2.EmpID = t1.EmpID
ORDER BY t1.EmpID,
t1.StartTime,
t2.StartTime
That won't get you the EXACT format you have listed, but it's close. You should end up with:
| EmpID| Name| Normal Period | Overlapping Period |
------------------------------------------------------------
| 1 | Jon | 10:00 AM | 12:15 PM | 11:00 AM | 02:15 PM |
------------------------------------------------------------
| 2 | Smith | 10:00 AM | 12:10 PM | NULL | NULL |
------------------------------------------------------------
Each overlapped period within a normal period would show up in a new row, but any period with no overlaps would have only one row. You could easily concatenate the fields if you wanted specifically the "xx:xx xx to xx:xx xx" format. Hope this helps you some.

Related

Nested Hierarchy to Calculated Date

I am trying to convert an nested hierarchy from a currency holiday table to select the specific date occurrence for 2022.
Sample source table for explanation:
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| hol_ccy | holiday | date_type | hol_dt | hol_day_no | calloc_id | base_hol_id |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| CHF | Good Friday | Date | 2022-04-15 00:00:00.000 | 0 | 9169 | NULL |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| CHF | Easter Monday | Ordinal Based | 1899-12-30 00:00:00.000 | 3 | 9188 | 9169 |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| CHF | Easter | Ordinal Based | 1899-12-30 00:00:00.000 | 2 | 9189 | 9169 |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| CHF | Ascension | Ordinal Based | 1899-12-30 00:00:00.000 | 39 | 9190 | 9189 |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
| CHF | Whit Monday | Ordinal Based | 1899-12-30 00:00:00.000 | 50 | 9191 | 9189 |
+---------+---------------+---------------+-------------------------+------------+-----------+-------------+
Desired Output:
CCY HOLIDAY DATE
CHF Good Friday 2022-04-15 00:00:00.000
CHF Easter Monday 2022-04-18 00:00:00.000
CHF Easter 2022-04-17 00:00:00.000
CHF Ascension 2022-05-26 00:00:00.000
CHF Whit Monday 2022-06-06 00:00:00.000
Row 1 is a given fact entered into the database for each year. Given as date_type: date
Rows 2 & 3 are based on Row 1. Each adding the value of hol_day_no to row 1's hol_dt (date). This relationship is described in calloc_id and base_hol_id columns
Rows 4 & 5 are based on Row 3.
I cant figure out how to treat the nesting of the ordinal based date types in SQL.
Any pointers would be appreciated.
It looks like a pretty simple recursive CTE is needed. You just need to add the child row's day number to the parent row's date.
WITH cte AS (
SELECT
t.hol_ccy,
t.holiday,
t.hol_dt,
t.calloc_id
FROM YourTable t
WHERE t.base_hol_id IS NULL
UNION ALL
SELECT
t.hol_ccy,
t.holiday,
DATEADD(day, t.hol_day_no, cte.hol_dt),
t.calloc_id
FROM YourTable t
JOIN cte ON cte.calloc_id = t.base_hol_id
)
SELECT
t.hol_ccy,
t.holiday,
t.hol_dt
FROM cte t;
db<>fiddle

Working hours between two dates in Snowflake

How to calculate working hours between two dates in snowflake without creating tables?
i have tried function like (datediff) and timestamp but i could not reach the solution
i would like to get something like that
+---------------------+---------------------+---------------+
| create_Task | Solved_Task | BusinessHours |
+---------------------+---------------------+---------------+
| 2012-03-05 09:00:00 | 2012-03-05 15:00:00 | 6.000000 |
| 2012-03-05 10:00:00 | 2012-03-06 10:00:00 | 8.000000 |
| 2012-03-05 11:00:00 | 2012-03-06 10:00:00 | 7.000000 |
| 2012-03-05 10:00:00 | 2012-03-06 15:00:00 | 13.000000 |
| 2012-03-09 16:00:00 | 2012-03-12 10:00:00 | 2.000000 |
| 2012-03-06 16:00:00 | 2012-03-15 10:00:00 | 50.000000 |
| 2012-03-09 16:00:00 | 2012-03-19 10:00:00 | 42.000000 |
+---------------------+---------------------+---------------+
and i would like to specify the working hours so then i can calculate the business hours
One way to do this is by creating a working hours table. Then you can run a fairly simple query:
select
t.id
, sum(datediff(‘second’,
-- calculate the max of the two start time
(case when t.start <=
w.working_day_start_timestamp
then w.working_day_start_timestamp
else t.start
end),
-- calculate the min of the two end times
(case when t.end >=
w.working_day_end_timestamp
then w.working_day_end_timestamp
else t.end
end)
)) / 3600 -- convert to hourly
as working_hour_diff
from
working_days_times w,
cross join time_intervals t
where -- select all intersecting intervals
(
t.start <= w.working_day_end_timestamp
and
t.end >= w.working_day_start_timestamp
)
and -- select only working days
w.is_working_day
group by
t.id
If you need a function, this article describes the implementation of a Javascript UDF in Snowflake:
https://medium.com/dandy-engineering-blog/how-to-calculate-the-number-of-working-hours-between-two-timestamps-in-sql-b5696de66e51

Netezza Convert UTC/GMT to Central with Daylight Savings Time

I am working in a Netezza database that stores time as GMT (or so I am told by our data engineers). I need to be able to convert this to Central Standard Time (CST) but accounting for daylight savings time. I found that I could use something like:
SELECT CURRENT_TIMESTAMP, CURRENT_TIMESTAMP AT TIME ZONE 'CST' AT TIME ZONE 'GMT'
However, when I run this SELECT (keep in mind, today is March 30, 2021 - CST should only be 5 hours different from GTM), I get a 6 hour difference.... I looked up a reference to see what time zones are available in Netezza and I see a "CDT" which is 5 hours, and that works for the 5 hour difference, but this means in my query I would need to either change this each time DST switches over or do some sort of elaborate case statement to know which one to use depending on the date/time of year.
Is there an easy automated way to convert a GTM time to Central Standard Time accounting for daylight savings time? Thanks so much!!!
The question can be interpreted one of two ways. In both cases, the solution is to determine the timezone to convert to, based on whether the timestamp is between 2 AM 2nd Sunday of March and 2 AM on 1st Sunday of Nov (for US Central timezone)
The timestamps in your table, need to be converted to CST or CDT based on the current time (when the query is being run)
this means if the same query was run in Feb, the results would be different than if its run now
also it would be different based on what the timezone of the netezza system is set to
Eg
select
t as original,
-- extract year from current date and 2nd Sunday of March
-- use last_day to make sure we account for March 1 being a Sunday
(next_day(next_day(
last_day((date_part('years', current_date) || '-02-01'):: date),
'sun'),
'sun')|| ' 02:00:00'):: timestamp as dstart,
-- extract year from current date and 1st Sunday of Nov
-- use last_day to make sure we account for Nov 1 being a Sunday
(next_day(last_day(
(date_part('years', current_date) || '-10-01')::date),
'sun')|| ' 02:00:00'):: timestamp as dend,
case when current_timestamp between dstart
and dend then 'CDT' else 'CST' end as tz,
t at time zone tz as converted
from
tdata;
will produce
ORIGINAL | DSTART | DEND | TZ | CONVERTED
---------------------+---------------------+---------------------+-----+------------------------
2021-01-01 17:00:00 | 2021-03-14 02:00:00 | 2021-11-07 02:00:00 | CDT | 2021-01-01 12:00:00-05
2021-04-01 17:00:00 | 2021-03-14 02:00:00 | 2021-11-07 02:00:00 | CDT | 2021-04-01 12:00:00-05
2020-04-01 17:00:00 | 2021-03-14 02:00:00 | 2021-11-07 02:00:00 | CDT | 2020-04-01 12:00:00-05
2020-12-01 17:00:00 | 2021-03-14 02:00:00 | 2021-11-07 02:00:00 | CDT | 2020-12-01 12:00:00-05
(4 rows)
OR
The timestamps in your table need to be converted to CST or CDT depending on when the daylight savings started/ended in the respective year as defined in the time stamp.
this is more deterministic
select
t as original,
-- extract year from this timestamp and 2nd Sunday of March
-- use last_day to make sure we account for March 1 being a Sunday
(next_day(next_day(
last_day((date_part('years', t) || '-02-01'):: date), 'sun'),
'sun')|| ' 02:00:00'):: timestamp as dstart,
-- extract year from this timestamp and 1st Sunday of Nov
-- use last_day to make sure we account for Nov 1 being a Sunday
(next_day(last_day((date_part('years', t) || '-10-01')::date),
'sun')|| ' 02:00:00'):: timestamp as dend,
case when current_timestamp between dstart
and dend then 'CDT' else 'CST' end as tz,
t at time zone tz as converted
from
tdata;
This will produce (tdata is a sample table w/ 4 timestamps)
ORIGINAL | DSTART | DEND | TZ | CONVERTED
---------------------+---------------------+---------------------+-----+------------------------
2021-01-01 17:00:00 | 2021-03-14 02:00:00 | 2021-11-07 02:00:00 | CST | 2021-01-01 11:00:00-06
2021-04-01 17:00:00 | 2021-03-14 02:00:00 | 2021-11-07 02:00:00 | CDT | 2021-04-01 12:00:00-05
2020-04-01 17:00:00 | 2020-03-08 02:00:00 | 2020-11-01 02:00:00 | CDT | 2020-04-01 12:00:00-05
2020-12-01 17:00:00 | 2020-03-08 02:00:00 | 2020-11-01 02:00:00 | CST | 2020-12-01 11:00:00-06
(4 rows)
system.admin(admin)=> select '2021-04-07 11:00:00' as gmt, timezone('2021-04-07 11:00:00' , 'GMT', 'America/New_York') as eastern, timezone('2021-04-07 11:00:00', 'GMT', 'America/Chicago') as central, timezone('2021-04-07 11:00:00', 'GMT', 'America/Los_Angeles') as pacific;
gmt | eastern | central | pacific
---------------------+---------------------+---------------------+---------------------
2021-04-07 11:00:00 | 2021-04-07 07:00:00 | 2021-04-07 06:00:00 | 2021-04-07 04:00:00
(1 row)
system.admin(admin)=> select '2021-03-07 11:00:00' as gmt, timezone('2021-03-07 11:00:00' , 'GMT', 'America/New_York') as eastern, timezone('2021-03-07 11:00:00', 'GMT', 'America/Chicago') as central, timezone('2021-03-07 11:00:00', 'GMT', 'America/Los_Angeles') as pacific;
gmt | eastern | central | pacific
---------------------+---------------------+---------------------+---------------------
2021-03-07 11:00:00 | 2021-03-07 06:00:00 | 2021-03-07 05:00:00 | 2021-03-07 03:00:00
(1 row)
Instead of CDT and CST if we use 'America/Chicago' as shown above it takes care of daylight savings.

Using SQL Server windowing function to get running total by fiscal year

I'm using SQL Server 2014. I have a Claims table containing totals of claims made per month in my system:
+-----------+-------------+------------+
| Claim_ID | Claim_Date | Nett_Total |
+-----------+-------------+------------+
| 1 | 31 Jan 2012 | 321454.67 |
| 2 | 29 Feb 2012 | 523542.34 |
| 3 | 31 Mar 2012 | 35344.33 |
| 4 | 30 Apr 2012 | 142355.63 |
| etc. | etc. | etc. |
+-----------+-------------+------------+
For a report I am writing I need to be able to produce a cumulative running total that resets to zero at the start of each fiscal year (in my country this is from March 1 to February 28/29 of the following year).
The report will look similar to the table, with an extra running total column, something like:
+-----------+-------------+------------+---------------+
| Claim_ID | Claim_Date | Nett_Total | Running Total |
+-----------+-------------+------------+---------------+
| 1 | 31 Jan 2012 | 321454.67 | 321454.67 |
| 2 | 29 Feb 2012 | 523542.34 | 844997.01 |
| 3 | 31 Mar 2012 | 35344.33 | 35344.33 | (restart at 0
| 4 | 30 Apr 2012 | 142355.63 | 177699.96 | for new yr)
| etc. | etc. | etc. | |
+-----------+-------------+------------+---------------+
I know windowing functions are very powerful and I've used them in rudimentary ways in the past to get overall sums and averages while avoiding needing to group my resultset rows. I have an intuition that I will need to employ the 'preceding' keyword to get the running total for the current fiscal year each row falls into, but I can't quite grasp how to express the fiscal year as a concept to use in the 'preceding' clause (or if indeed it's possible to use a date range in this way).
Any assistance on the way of "phrasing" the fiscal year for the "preceding" clause will be of enormous help to me, please.
i think you should try this:
/* Create Table*/
CREATE TABLE dbo.Claims (
Claim_ID int
,Claim_Date datetime
,Nett_Total decimal(10,2)
);
/* Insert Testrows*/
INSERT INTO dbo.Claims VALUES
(1, '20120101', 10000)
,(2, '20120202', 10000)
,(3, '20120303', 10000)
,(4, '20120404', 10000)
,(5, '20120505', 10000)
,(6, '20120606', 10000)
,(7, '20120707', 10000)
,(8, '20120808', 10000)
Query the Data:
SELECT Claim_ID, Claim_Date, Nett_Total, SUM(Nett_Total) OVER
(PARTITION BY YEAR(DATEADD(month,-2,Claim_Date)) ORDER BY Claim_ID) AS
[Running Total] FROM dbo.Claims
The Trick: PARTITION BY YEAR(DATEADD(month,-2,Claim_Date))
New Partition by year, but i change the date so it fits your fiscal year.
Output:
Claim_ID |Claim_Date |Nett_Total |Running Total
---------+---------------------------+------------+-------------
1 |2012-01-01 00:00:00.000 |10000.00 |10000.00
2 |2012-02-02 00:00:00.000 |10000.00 |20000.00
3 |2012-03-03 00:00:00.000 |10000.00 |10000.00 <- New partition
4 |2012-04-04 00:00:00.000 |10000.00 |20000.00
5 |2012-05-05 00:00:00.000 |10000.00 |30000.00
6 |2012-06-06 00:00:00.000 |10000.00 |40000.00
7 |2012-07-07 00:00:00.000 |10000.00 |50000.00
8 |2012-08-08 00:00:00.000 |10000.00 |60000.00

finding date in sql

i need a query to find the date based on year, month, day of the week and weekday number. Say for example, if the question is to find the date of 2nd Sunday of January 2010, the answer should be '2010-01-10'.
Inputs are
Yr | Mon | Dy | Dyno
-----------------------
2010 | Jan | Sun | 2
2005 | Jan | Mon | 3
1995 | Feb | Sun | 1
2000 | Feb | Wed | 4
1982 | Mar | Tue | 2
2010 | Mar | Tue | 8
Dyno states dayno
The easiest answer to many date-related questions in SQL is to create a calendar table. In your case, if you create a table with the columns you've already shown, and an extra one with the DATETIME value that you want (call it BaseDate), you can get the value you need with a simple query:
select BaseDate
from dbo.Calendar
where Yr = 2010 and Mon = 'Jan' and Dy = 'Sunday' and Dyno = 2
Of course, your calendar table can have 10, 20 or more columns, depending on what values you find useful for your queries.

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