I have a cost record and I would like to create N records from it.
The children records have some different parameters.
For example:
The parents record:
date | amount | duration
20170201 | 5000 | 5 months
The children records:
date | amount | duration
20170301 | 1000 | 1 months
20170401 | 1000 | 1 months
20170501 | 1000 | 1 months
20170601 | 1000 | 1 months
20170701 | 1000 | 1 months
How can I do this without iteration? Without cursor or while?
Following SQL CTE query could be used based on Abdul's solution
/*
Create Table PARENT (PARENT_DATE DATE, PARENT_AMOUNT DECIMAL(18,2),PARENT_MONTH INT)
INSERT INTO PARENT SELECT '20170201',5000 ,5
INSERT INTO PARENT SELECT '20180601',120 ,3
*/
;WITH CTE_CHILD
AS (
SELECT
Parent_Date,
Parent_Amount,
Parent_Month,
DateAdd(Month, 1, Parent_Date) as Child_Date,
Parent_Amount/Parent_Month AS Child_Amount,
1 AS Child_Duration
FROM Parent
UNION ALL
SELECT
Parent_Date,
Parent_Amount,
Parent_Month,
DateAdd(Month, 1, Child_Date) as Child_Date,
Child_Amount,
Child_Duration
FROM CTE_CHILD
WHERE
DateAdd(Month, 1, Child_Date) <= DateAdd(Month, Parent_Month, Parent_Date)
)
SELECT
Child_Date,
Child_Amount,
Child_Duration
FROM CTE_CHILD
assuming you have a table like below:
create table tblRecords ( date int, amount money, duration int);
insert into tblRecords values
(20170201,5000,5),
(20180101,9000,3);
you can use a query like below:
select
date= date + r*100
,amount= amount/duration
,duration =1
from tblRecords
cross apply
(
select top (select duration)
r= row_number() over(order by (select null))
from
sys.objects s1
cross join
sys.objects s2
) h
see working demo
One method is CTE.
DECLARE #PARENT AS TABLE
(PARENT_DATE DATE, PARENT_AMOUNT DECIMAL(18,2),PARENT_MONTH INT)
INSERT INTO #PARENT
SELECT '20170201',5000 ,5
;WITH CTE_CHILD
AS (
SELECT DATEADD(MONTH,1,PARENT_DATE) AS CHILD_DATE
,PARENT_AMOUNT/PARENT_MONTH AS CHILD_AMOUNT
,1 AS CHILD_DURATION
FROM #PARENT
WHERE DATEADD(MONTH,1,PARENT_DATE) <= DATEADD(MONTH,PARENT_MONTH,PARENT_DATE)
UNION ALL
SELECT DATEADD(MONTH,1,CHILD_DATE)
,PARENT_AMOUNT/PARENT_MONTH
,1
FROM CTE_CHILD
INNER JOIN #PARENT ON DATEADD(MONTH,1,CHILD_DATE) <= DATEADD(MONTH,PARENT_MONTH,PARENT_DATE)
)
SELECT * FROM CTE_CHILD
option (maxrecursion 0)
Output:-
CHILD_DATE CHILD_AMOUNT CHILD_DURATION
2017-03-01 1000.0000000000000 1
2017-04-01 1000.0000000000000 1
2017-05-01 1000.0000000000000 1
2017-06-01 1000.0000000000000 1
2017-07-01 1000.0000000000000 1
Related
I have a table with, for example this data:
ID |start_date |end_date |amount
---|------------|-----------|--------
1 |2019-03-21 |2019-05-09 |10000.00
2 |2019-04-02 |2019-04-10 |30000.00
3 |2018-11-01 |2019-01-08 |20000.00
I would like te get the splitted records back with the correct calculated amount based on the year/month.
I expect the outcome to be like this:
ID |month |year |amount
---|------|-------|--------
1 |3 | 2019 | 2200.00
1 |4 | 2019 | 6000.00
1 |5 | 2019 | 1800.00
2 |4 | 2019 |30000.00
3 |11 | 2018 | 8695.65
3 |12 | 2018 | 8985.51
3 |1 | 2019 | 2318.84
What would be the best way to achieve this? I think you would have to use DATEDIFF to get the number of days between the start_date and end_date to calculate the amount per day, but I'm not sure how to return it as records per month/year.
Tnx in advance!
This is one idea. I use a Tally to create a day for every day the amount is relevant for for that ID. Then, I aggregate the value of the Amount divided by the numbers of days, which is grouped by Month and year:
CREATE TABLE dbo.YourTable(ID int,
StartDate date,
EndDate date,
Amount decimal(12,2));
GO
INSERT INTO dbo.YourTable (ID,
StartDate,
EndDate,
Amount)
VALUES(1,'2019-03-21','2019-05-09',10000.00),
(2,'2019-04-02','2019-04-10',30000.00),
(3,'2018-11-01','2019-01-08',20000.00);
GO
--Create a tally
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
SELECT TOP (SELECT MAX(DATEDIFF(DAY, t.StartDate, t.EndDate)+1) FROM dbo.YourTable t) --Limits the rows, might be needed in a large dataset, might not be, remove as required
ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) -1 AS I
FROM N N1, N N2, N N3), --1000 days, is that enough?
--Create the dates
Dates AS(
SELECT YT.ID,
DATEADD(DAY, T.I, YT.StartDate) AS [Date],
YT.Amount,
COUNT(T.I) OVER (PARTITION BY YT.ID) AS [Days]
FROM Tally T
JOIN dbo.YourTable YT ON T.I <= DATEDIFF(DAY, YT.StartDate, YT.EndDate))
--And now aggregate
SELECT D.ID,
DATEPART(MONTH,D.[Date]) AS [Month],
DATEPART(YEAR,D.[Date]) AS [Year],
CONVERT(decimal(12,2),SUM(D.Amount / D.[Days])) AS Amount
FROM Dates D
GROUP BY D.ID,
DATEPART(MONTH,D.[Date]),
DATEPART(YEAR,D.[Date])
ORDER BY D.ID,
[Year],
[Month];
GO
DROP TABLE dbo.YourTable;
GO
DB<>Fiddle
I have a case where I need to write a CTE ( at least this seems like the best approach) . I have almost everything I need in place but one last issue. I am using a CTE to generate many millions of a records and then I will insert them into a table. The data itself is almost irrelevant except for three columns. 2 date time columns and one character column.
The idea behind the CTE is this. I want one datetime field called Start and one int field called DataValue. I will have a variable which is the count of records I want to aim for and then another variable which is the number of times I want to repeat the datetime value. I don't think I need to explain the software this data represents but basically I need to have 16 rows where the Start value is the same and then after the 16th run I want to then add 15 minutes and then repeat. Effectively there will be events in 15 minute intervals and I will need X number of rows per 15 minute interval to represent those events.
This is my code
Declare #tot as int;
Declare #inter as int;
Set #tot = 26
Set #inter = 3;
WITH mycte(DataValue,start) AS
(
SELECT 1 DataValue, cast('01/01/2011 00:00:00' as datetime) as start
UNION all
if DataValue % #inter = 0
SELECT
DataValue + 1,
cast(DateAdd(minute,15,start) as datetime)
else
select
DataValue + ,
start
FROM mycte
WHERE DataValue + 1 <= #tot)
select
m.start,
m.start,
m.Datavalue%#inter
from mycte as m
option (maxrecursion 0);
I'll change the select statement into an insert statement once I get it working but the m.DataValue%#inter will make it repeat integer when inserting so the only thing I need is to figure out how to make the start be the same 16 times in a row and then increment
It seems that I cannot have an IF statement in the CTE but I am not sure how to accomplish that but what I was going to do was basically say if the DataValue%16 was 0 then increase the value of start.
In the end I should hopefully have something like this where in this case I only repeat it 4 times
+-----------+-------------------+
| DateValue | start |
+-----------+-------------------+
| 1 | 01/01/01 00:00:00 |
| 2 | 01/01/01 00:00:00 |
| 3 | 01/01/01 00:00:00 |
| 4 | 01/01/01 00:00:00 |
| 5 | 01/01/01 00:15:00 |
| 6 | 01/01/01 00:15:00 |
| 7 | 01/01/01 00:15:00 |
| 8 | 01/01/01 00:15:00 |
Is there another way to accomplish this without conditional statements?
You can use case when as below:
Declare #tot as int;
Declare #inter as int;
Set #tot = 26
Set #inter = 3;
WITH mycte(DataValue,start) AS
(
SELECT 1 DataValue, cast('01/01/2011 00:00:00' as datetime) as start
UNION all
SELECT DataValue+1 [Datavalue],
case when (DataValue % #inter) = 0 then cast(DateAdd(minute,15,start) as datetime) else [start] end [start]
FROM mycte
WHERE (DataValue + 1) <= #tot)
select
m.DataValue,
m.[start]
from mycte as m
option (maxrecursion 0);
This will give the below result
DataValue Start
========= =============
1 2011-01-01 00:00:00.000
2 2011-01-01 00:00:00.000
3 2011-01-01 00:00:00.000
4 2011-01-01 00:15:00.000
5 2011-01-01 00:15:00.000
6 2011-01-01 00:15:00.000
7 2011-01-01 00:30:00.000
8 2011-01-01 00:30:00.000
9 2011-01-01 00:30:00.000
10 2011-01-01 00:45:00.000
11 2011-01-01 00:45:00.000
12 2011-01-01 00:45:00.000
....
26 2011-01-01 02:00:00.000
And if you dont want to use case when you can use double recursive cte as below:-
WITH mycte(DataValue,start) AS
( --this recursive cte will generate the same record the number of #inter
SELECT 1 DataValue, cast('01/01/2011 00:00:00' as datetime) as start
UNION all
SELECT DataValue+1 [DataValue],[start]
FROM mycte
WHERE (DataValue + 1) <= #inter)
,Increments as (
-- this recursive cte will do the 15 additions
select * from mycte
union all
select DataValue+#inter [DataValue]
,DateAdd(minute,15,[start]) [start]
from Increments
WHERE (DataValue + 1) <= #tot
)
select
m.DataValue,
m.[start]
from Increments as m
order by DataValue
option (maxrecursion 0);
it will give the same results.
You can do this with a tally table and some basic math. I'm not sure if your total rows are #tot or should they be #tot * #inter. If so, you just need to change the TOP clause. If you need more rows, you just need to alter the tally table generation.
Declare #tot as int;
Declare #inter as int;
Set #tot = 26
Set #inter = 3;
WITH
E(n) AS(
SELECT n FROM (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0))E(n)
),
E2(n) AS(
SELECT a.n FROM E a, E b
),
E4(n) AS(
SELECT a.n FROM E2 a, E2 b
),
cteTally(n) AS(
SELECT TOP( #tot) ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) n
FROM E4
)
SELECT n, DATEADD( MI, 15* ((n-1)/#inter), '20110101')
FROM cteTally;
I want to convert some line of code from Oracle query to MSSQL.
WITH DATE_MONTHS AS
(
SELECT TO_CHAR(ADD_MONTHS(TO_DATE(TRUNC(TO_DATE(P_REQUIRED_DATE),'MON')), - LEVEL
+1),'DD-MON-YYYY') MONTHS FROM DUAL
CONNECT BY LEVEL <= P_MONTH_RANG
)
SELECT * from DATE_MONTHS
Parameters:
P_REQUIRED_DATE i.e sysdate
P_MONTH_RANG i.e 4
Result:
01-05-2017
01-04-2017
01-03-2017
01-02-2017
One simple way is to use tally table and generate like below:
declare #P_Required_Date date = '2015-05-01'
declare #P_Month_Rang int = 4
Select top (#P_Month_Rang) Dts = DateAdd(month, -(Row_Number() over(order by (Select NULL))-1), #P_Required_Date) from
master..spt_values s1, master..spt_values s2
Output as below:
+------------+
| Dts |
+------------+
| 2015-05-01 |
| 2015-04-01 |
| 2015-03-01 |
| 2015-02-01 |
+------------+
Your CTE approach:
declare #P_Required_Date date = '2015-05-01'
declare #P_Month_Rang int = 4
;with Date_Months as
(
Select #P_Required_Date as Dates, 1 as Levl
Union all
Select DateAdd(MONTH,-1, Dates), Levl+1 as Levl from Date_Months
where Levl < #P_Month_Rang
)
Select convert(varchar(10), dates, 103) from Date_Months
For converting to your dd-mm-yyyy format one way is to do convert with option 103 or use Format.
Another option using Stacked Ctes
declare #fromdate date = '20150501';
declare #months int = 4;
;with n as (select n from (values(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) t(n))
, dates as (
select top (#months)
[Date]=convert(date,dateadd(month,-(row_number() over(order by (select 1))-1),#fromdate))
from n as deka cross join n as hecto cross join n as kilo cross join n as tenK
order by [Date] desc
)
select [Date] = convert(char(10),[date],105)
from dates;
rextester demo: http://rextester.com/UUW2271
returns:
+------------+
| Date |
+------------+
| 01-05-2015 |
| 01-04-2015 |
| 01-03-2015 |
| 01-02-2015 |
+------------+
Benchmarks & Performance testing: Generate a set or sequence without loops - 2 - Aaron Bertrand
I have a table that shows the entry and exit of items into the warehouse. The Camera 1 and Camera 2 document the entry time and exit time respectively of that item. The cameras then classify the item as it enters and leaves the checkpoint with the help of lasers. Eg: Big box: Class 5, Medium Box: Class 3, Small Box: Class 2.
Sometimes, the cameras classification doesn't match each other. Eg: Classification at entry can be Medium box and on exit can be Small box.
I need to find the number of transactions where the class didn't match for the same TransactionDetail and then a percentage of those class mismatches against all the transaction for a certain time range.
My table looks somewhat like this:
---------------------------------------------------------------------------
| AVDetailID | TransDetailID | AVClassID | CamID | CreatedDate |
---------------------------------------------------------------------------
| 20101522 | 54125478 | 5 | 1 | 2017-05-08 10:15:01:560|
| 20101523 | 54125478 | 5 | 2 | 2017-05-08 10:15:01:620|
| 20101524 | 54125479 | 3 | 1 | 2017-05-08 10:15:03:120|
| 20101525 | 54125479 | 2 | 2 | 2017-05-08 10:15:03:860|
| 20101526 | 54125480 | 4 | 1 | 2017-05-08 10:15:06:330|
| 20101527 | 54125480 | 4 | 2 | 2017-05-08 10:15:06:850|
---------------------------------------------------------------------------
So, in the above case the class changes from 3 to 2 in record 3 and 4. That is one transaction where the class changed. I need to get a percentage of all transactions that where the class changed between each cameras.
The code I've used so far is below. I just need to find a way to get a percentage of the total Transactions.
DECLARE #MinDate DATE = '20170406',
#MaxDate DATE = '20170407';
SELECT COUNT(tdBefore.TransDetailId) TD
--,SUM((COUNT(*) OVER() / allRecords.Count) * 100) AS DiffPercent
FROM AVTransDetail AS tdBefore
INNER JOIN AVTransDetail AS tdAfter
ON tdBefore.TransDetailID = tdAfter.TransDetailID
AND tdBefore.ACClassID = 1
AND tdAfter.ACClassID = 2
CROSS APPLY
(
SELECT COUNT(*) AS [Count]
FROM AVTransDetail
WHERE tdBefore.DateCreated >= #MinDate
AND tdAfter.DateCreated <= #MaxDate
) AS allRecords
WHERE tdBefore.AVCClassId <> tdAfter.AVCClassId
AND tdBefore.DateCreated >= #MinDate
AND tdAfter.DateCreated <= #MaxDate
How do I create a column for percentage of total transactions?
This worked with your sample data.
DECLARE #MinDate DATETIME = '5/8/2017 12:00AM';
DECLARE #MaxDate DATETIME = '5/8/2017 11:59PM';
WITH cam1 AS (
SELECT TransDetailID,AVClassID
FROM AVTransDetail
WHERE CreatedDate BETWEEN #MinDate AND #MaxDate
AND
CamID = 1),
cam2 AS (
SELECT TransDetailID,AVClassID
FROM AVTransDetail
WHERE CreatedDate BETWEEN #MinDate AND #MaxDate
AND
CamID = 2)
SELECT COUNT(*)'Total',SUM(CASE WHEN c1.AVClassID = c2.AVClassID THEN 0 ELSE 1 END)'NonMatch',
SUM(CASE WHEN c1.AVClassID = c2.AVClassID THEN 0 ELSE 1 END) * 100.00/COUNT(*)'Percentage'
FROM cam1 c1
JOIN cam2 c2 ON c1.TransDetailID=c2.TransDetailID
Try the below SQL script.
First we LAG to find the differences. Then, we get each transaction and whether there is a difference. And finally, we get the percentage.
DECLARE #MinDate DATE = '2017/04/06',
#MaxDate DATE = '2017/05/09';
SELECT count(*) AS TotalTransactions
,sum(Change) AS TransactionsWithChange
,(cast(sum(Change) AS FLOAT) / cast(count(*) AS FLOAT)) AS ChangePercent
FROM (
SELECT TransDetailID
,MAX(classChange) AS Change
FROM (
SELECT *
,LAG(AVClassID, 1, AVClassID) OVER (
PARTITION BY TransDetailID ORDER BY AVDetailID
) AS PrevClassId
,CASE
WHEN LAG(AVClassID, 1, AVClassID) OVER (
PARTITION BY TransDetailID ORDER BY AVDetailID
) != AVClassID
THEN 1
ELSE 0
END AS ClassChange
FROM AVTransDetail
where CreatedDate between #MinDate and #MaxDate
) AS CoreData
GROUP BY TransDetailID
) AS ChangeData
Hope this helps.
I added more sample rows to get better result
create table #trans (
AVDetailID int,
TransDetailID int,
AVClassID int,
CamID int,
CreatedDate datetime
)
insert into #trans values
( 20101522, 54125478, 5, 1, '2017-05-08 10:15:01:560'),
( 20101523, 54125478, 5, 2, '2017-05-08 10:15:01:620'),
( 20101524, 54125479, 3, 1, '2017-05-08 10:15:03:120'),
( 20101525, 54125479, 2, 2, '2017-05-08 10:15:03:860'),
( 20101526, 54125480, 4, 1, '2017-05-08 10:15:06:330'),
( 20101527, 54125480, 4, 2, '2017-05-08 10:15:06:850'),
( 20101528, 54125481, 4, 1, '2017-05-08 10:15:07:850'),
( 20101529, 54125481, 5, 2, '2017-05-08 10:15:09:850'),
( 20101530, 54125482, 4, 1, '2017-05-08 10:15:07:850'),
( 20101531, 54125482, 5, 3, '2017-05-08 10:15:09:850')
;with diff as (
-- select records that have different class
select CamID as Ent_CamID, count(*) diff_Count
from #trans ent
outer apply (
select top 1 AVClassID as x_AVClassID, CamID as x_CamID from #trans
where CreatedDate > ent.CreatedDate and TransDetailID = ent.TransDetailID
order by CamID, CreatedDate desc
) ext
where ent.AVClassID <> ext.x_AVClassID
group by ent.CamID, ext.x_CamID
union
select ext.x_CamID as Ext_CamID, count(*) diff_Count
from #trans ent
outer apply (
select top 1 AVClassID as x_AVClassID, CamID as x_CamID from #trans
where CreatedDate > ent.CreatedDate and TransDetailID = ent.TransDetailID
order by CamID, CreatedDate desc
) ext
where ent.AVClassID <> ext.x_AVClassID
group by ent.CamID, ext.x_CamID
)
, perc as (
select Ent_CamID as CamID, sum(diff_Count) Total_Error
, (select count(*)
from #trans where CamID = diff.Ent_CamID
group by CamID) AS Total_Capture
from diff
group by Ent_CamID
)
select CamID, Total_Error, Total_Capture, 100*(Total_Error)/Total_Capture Error_Percentage
from perc
Result:
CamID Total_Error Total_Capture Error_Percentage
1 3 5 60
2 2 4 50
3 1 1 100
I have a SQL Server table named AgentLog in which I store for each agent his daily number of sales.
+-----------+------------+-------------+
| AgentName | Date | SalesNumber |
+-----------+------------+-------------+
| John | 01.01.2014 | 45 |
| Terry | 01.01.2014 | 30 |
| John | 02.01.2014 | 20 |
| Terry | 02.01.2014 | 15 |
| Terry | 03.01.2014 | 52 |
| Terry | 04.01.2014 | 24 |
| Terry | 05.01.2014 | 12 |
| Terry | 06.01.2014 | 10 |
| Terry | 07.01.2014 | 23 |
| John | 08.01.2014 | 48 |
| Terry | 08.01.2014 | 35 |
| John | 09.01.2014 | 37 |
| Terry | 10.01.2014 | 35 |
+-----------+------------+-------------+
If an agent doesn't work on one particular day, there is no record of his sales on that date.
I want to generate a report(query) on a given date interval (ex: 01.01.2014 - 10.01.2014) that counts on how many days an agent wasn't present for work (ex: John - 6 days), was at work (John - 4 days) and also returns the date interval it wasn't present (ex: John 03.01.2014 - 07.01.2014, 10.01.2014) (there can be multiple intervals).
You need to create a custom table and populate it with a record for each date you want in your range (Feel free to go as far back in the past and forward into the future as you feel you may need.). You could do this in Excel very easily and import it.
Select *
from Custom.DateListTable dlt
left outer join agentlog ag
on dlt.Date = ag.Date
I would approach this by getting the number of dates in the interval, as well as the number of dates the agent was at work, and you then have everything you need.
To get the number of days you can use DATEDIFF:
SELECT DATEDIFF(day, '2014-01-01', '2014-10-01') AS totalDays;
To get the number of days an agent worked, you can use the COUNT(*) aggregate function:
SELECT agentName, COUNT(*) AS daysWorked
FROM myTable
GROUP BY agentName;
Then, you can just add to that query to get the days not worked by subtracting totalDays - daysWorked:
SELECT agentName, COUNT(*) AS daysWorked, (DATEDIFF(day, '2014-01-01', '2014-10-01') - COUNT(*)) AS daysMissed
FROM myTable
GROUP BY agentName;
Here is an SQL Fiddle example.
The only way I can think of to resolve this is to creating a temporary table with only one column (datetime) and save there all the dates from the selected range. You can create an stored procedure that fills that temporary table using a cursor with all the dates from the interval. Then do a LEFT join between your table and the temporary table to look for null values in your table (The days where that person didn't come to work)
Try this...
SET DATEFIRST 1; --Monday
DECLARE #StartDate DATETIME = '2014-01.01',
#EndDate DATETIME = '2014-01.10';
WITH data as (
select 0 as i, DATEADD(DAY, 0, #StartDate) as TheDate
union all
select i + 1, DATEADD(DAY, i + 1, #StartDate) as TheDate
from data
where i < (#EndDate - #StartDate)
)
SELECT a.AgentName,
SUM(CASE WHEN c.Date IS NULL THEN 1 ELSE 0 END) AS Missing,
SUM(CASE WHEN c.Date IS NOT NULL THEN 1 ELSE 0 END) AS Working
FROM Agent a
JOIN data b ON NOT EXISTS(SELECT NULL FROM SpecialDate s WHERE s.date = b.TheDate)
LEFT JOIN AgentLog c ON
c.AgentName = a.AgentName
AND c.Date = b.TheDate
WHERE DATEPART(weekday, b.TheDate) <= 5
GROUP BY a.AgentName
OPTION (MAXRECURSION 10000);
It includes a check for weekends, as well as a reference to "SpecialDate" where a list of non working days can be maintained, and excluded from the check.
Reading your question again, I realise that this will only solve half your problem.
NOTE: The following answer mainly addresses the trickiest part of the question, which is how to obtain "absence from work" intervals.
Given these values as Interval Start - End dates:
DECLARE #IntervalStart DATE = '2013-12-30'
DECLARE #IntervalEnd DATE = '2014-01-10'
the following query gives you the "absence from work" intervals:
SELECT AgentName,
DATEADD(d, 1, t.[Date]) As OffWorkStart,
DATEADD(d, -1, t.NextDate) As OffWorkEnd
FROM (
SELECT AgentName, [Date], LEAD([Date]) OVER (PARTITION BY AgentName ORDER BY [Date] ASC) As NextDate,
DATEDIFF(DAY, [Date], LEAD([Date]) OVER (PARTITION BY AgentName ORDER BY [Date] ASC)) As NextMinusCurrent
FROM #AgentLog) t
WHERE t.NextMinusCurrent > 1
-- Get marginal beginning interval (in case such an interval exists)
UNION ALL
SELECT AgentName, #IntervalStart AS OffWorkStart, DATEADD(DAY, -1, MIN([Date])) AS OffWorkEnd
FROM #AgentLog
GROUP BY AgentName
HAVING MIN([Date]) > #IntervalStart
-- Get marginal ending interval (in case such an interval exists)
UNION ALL
SELECT AgentName, DATEADD(DAY, 1, MAX([Date])) AS OffWorkStart, #IntervalEnd
FROM #AgentLog
GROUP BY AgentName
HAVING MAX([Date]) < #IntervalEnd
ORDER By AgentName, OffWorkStart
With the input data you supplied, the above query gives you the following output:
AgentName OffWorkStart OffWorkEnd
---------------------------------------
John 2013-12-30 2013-12-31
John 2014-01-03 2014-01-07
John 2014-01-10 2014-01-10
Terry 2013-12-30 2013-12-31
Terry 2014-01-09 2014-01-09
The idea behind the basic part of the query is to employ the following nested query:
SELECT AgentName,
[Date],
LEAD([Date]) OVER (PARTITION BY AgentName ORDER BY [Date] ASC) As NextDate,
DATEDIFF(DAY, [Date], LEAD([Date]) OVER (PARTITION BY AgentName ORDER BY [Date] ASC)) As NextMinusCurrent
FROM #AgentLog
in order to get any existing gaps between the days a certain agent is present for work. A value of NextMinusCurrent > 1 indicates such a gap.
Counting days is trivial once you have the above query in place. E.g. placing the above query in a CTE you can count total number of absence days with sth like:
;WITH cte (
... query goes here
)
SELECT AgentName, SUM(DATEDIFF(DAY, OffWorkStart, OffWorkEnd) + 1) AS AbsenceDays
FROM cte
GROUP By AgentName
P.S. The above query makes use of SQL Server LEAD function, which is available from SQL SERVER 2012 onwards.
SQL Fiddle here
EDIT:
CTEs together with ROW_NUMBER() can be used to simulate LEAD function. The first part of the query becomes:
;WITH cte1 AS (
SELECT AgentName,
[Date],
ROW_NUMBER() OVER (PARTITION BY AgentName ORDER BY [Date] ASC) As rn
FROM #AgentLog
),
cte2 AS (
SELECT cte1.AgentName, cte1.[Date],
cteLead.[Date] AS NextDate,
DATEDIFF(DAY, cte1.[Date], cteLead.[Date]) As NextMinusCurrent
FROM cte1
LEFT OUTER JOIN cte1 AS cteLead
ON (cte1.rn = cteLead.rn - 1) AND (cte1.AgentName = cteLead.AgentName)
)
SELECT AgentName,
DATEADD(d, 1, cte2.[Date]) As OffWorkStart,
DATEADD(d, -1, cte2.NextDate) As OffWorkEnd
FROM cte2
WHERE NextMinusCurrent > 1
SQL Fiddle for SQL Server 2008 here. I hope it executes in SQL Server 2005 also!