I need to create a report and I am struggling with the SQL script.
The table I want to query is a company_status_history table which has entries like the following (the ones that I can't figure out)
Table company_status_history
Columns:
| id | company_id | status_id | effective_date |
Data:
| 1 | 10 | 1 | 2016-12-30 00:00:00.000 |
| 2 | 10 | 5 | 2017-02-04 00:00:00.000 |
| 3 | 11 | 5 | 2017-06-05 00:00:00.000 |
| 4 | 11 | 1 | 2018-04-30 00:00:00.000 |
I want to answer to the question "Get all companies that have been at least for some point in status 1 inside the time period 01/01/2017 - 31/12/2017"
Above are the cases that I don't know how to handle since I need to add some logic of type :
- "If this row is status 1 and it's date is before the date range check the next row if it has a date inside the date range."
- "If this row is status 1 and it's date is after the date range check the row before if it has a date inside the date range."
I think this can be handled as a gaps and islands problem. Consider the following input data: (same as sample data of OP plus two additional rows)
id company_id status_id effective_date
-------------------------------------------
1 10 1 2016-12-15
2 10 1 2016-12-30
3 10 5 2017-02-04
4 10 4 2017-02-08
5 11 5 2017-06-05
6 11 1 2018-04-30
You can use the following query:
SELECT t.id, t.company_id, t.status_id, t.effective_date, x.cnt
FROM company_status_history AS t
OUTER APPLY
(
SELECT COUNT(*) AS cnt
FROM company_status_history AS c
WHERE c.status_id = 1
AND c.company_id = t.company_id
AND c.effective_date < t.effective_date
) AS x
ORDER BY company_id, effective_date
to get:
id company_id status_id effective_date grp
-----------------------------------------------
1 10 1 2016-12-15 0
2 10 1 2016-12-30 1
3 10 5 2017-02-04 2
4 10 4 2017-02-08 2
5 11 5 2017-06-05 0
6 11 1 2018-04-30 0
Now you can identify status = 1 islands using:
;WITH CTE AS
(
SELECT t.id, t.company_id, t.status_id, t.effective_date, x.cnt
FROM company_status_history AS t
OUTER APPLY
(
SELECT COUNT(*) AS cnt
FROM company_status_history AS c
WHERE c.status_id = 1
AND c.company_id = t.company_id
AND c.effective_date < t.effective_date
) AS x
)
SELECT id, company_id, status_id, effective_date,
ROW_NUMBER() OVER (PARTITION BY company_id ORDER BY effective_date) -
cnt AS grp
FROM CTE
Output:
id company_id status_id effective_date grp
-----------------------------------------------
1 10 1 2016-12-15 1
2 10 1 2016-12-30 1
3 10 5 2017-02-04 1
4 10 4 2017-02-08 2
5 11 5 2017-06-05 1
6 11 1 2018-04-30 2
Calculated field grp will help us identify those islands:
;WITH CTE AS
(
SELECT t.id, t.company_id, t.status_id, t.effective_date, x.cnt
FROM company_status_history AS t
OUTER APPLY
(
SELECT COUNT(*) AS cnt
FROM company_status_history AS c
WHERE c.status_id = 1
AND c.company_id = t.company_id
AND c.effective_date < t.effective_date
) AS x
), CTE2 AS
(
SELECT id, company_id, status_id, effective_date,
ROW_NUMBER() OVER (PARTITION BY company_id ORDER BY effective_date) -
cnt AS grp
FROM CTE
)
SELECT company_id,
MIN(effective_date) AS start_date,
CASE
WHEN COUNT(*) > 1 THEN DATEADD(DAY, -1, MAX(effective_date))
ELSE MIN(effective_date)
END AS end_date
FROM CTE2
GROUP BY company_id, grp
HAVING COUNT(CASE WHEN status_id = 1 THEN 1 END) > 0
Output:
company_id start_date end_date
-----------------------------------
10 2016-12-15 2017-02-03
11 2018-04-30 2018-04-30
All you want know is those records from above that overlap with the specified interval.
Demo here with somewhat more complicated use case.
Maybe this is what you are looking for? For these kind of questions, you need to join two instance of your table, in this case I am just joining with next record by Id, which probably is not totally correct. To do it better, you can create a new Id using a windowed function like row_number, ordering the table by your requirement criteria
If this row is status 1 and it's date is before the date range check
the next row if it has a date inside the date range
declare @range_st date = '2017-01-01'
declare @range_en date = '2017-12-31'
select
case
when csh1.status_id=1 and csh1.effective_date<@range_st
then
case
when csh2.effective_date between @range_st and @range_en then true
else false
end
else NULL
end
from company_status_history csh1
left join company_status_history csh2
on csh1.id=csh2.id+1
Implementing second criteria:
"If this row is status 1 and it's date is after the date range check
the row before if it has a date inside the date range."
declare @range_st date = '2017-01-01'
declare @range_en date = '2017-12-31'
select
case
when csh1.status_id=1 and csh1.effective_date<@range_st
then
case
when csh2.effective_date between @range_st and @range_en then true
else false
end
when csh1.status_id=1 and csh1.effective_date>@range_en
then
case
when csh3.effective_date between @range_st and @range_en then true
else false
end
else null -- ¿?
end
from company_status_history csh1
left join company_status_history csh2
on csh1.id=csh2.id+1
left join company_status_history csh3
on csh1.id=csh3.id-1
I would suggest the use of a cte and the window functions ROW_NUMBER. With this you can find the desired records. An example:
DECLARE @t TABLE(
id INT
,company_id INT
,status_id INT
,effective_date DATETIME
)
INSERT INTO @t VALUES
(1, 10, 1, '2016-12-30 00:00:00.000')
,(2, 10, 5, '2017-02-04 00:00:00.000')
,(3, 11, 5, '2017-06-05 00:00:00.000')
,(4, 11, 1, '2018-04-30 00:00:00.000')
DECLARE @StartDate DATETIME = '2017-01-01';
DECLARE @EndDate DATETIME = '2017-12-31';
WITH cte AS(
SELECT *
,ROW_NUMBER() OVER (PARTITION BY company_id ORDER BY effective_date) AS rn
FROM @t
),
cteLeadLag AS(
SELECT c.*, ISNULL(c2.effective_date, c.effective_date) LagEffective, ISNULL(c3.effective_date, c.effective_date)LeadEffective
FROM cte c
LEFT JOIN cte c2 ON c2.company_id = c.company_id AND c2.rn = c.rn-1
LEFT JOIN cte c3 ON c3.company_id = c.company_id AND c3.rn = c.rn+1
)
SELECT 'Included' AS RangeStatus, *
FROM cteLeadLag
WHERE status_id = 1
AND effective_date BETWEEN @StartDate AND @EndDate
UNION ALL
SELECT 'Following' AS RangeStatus, *
FROM cteLeadLag
WHERE status_id = 1
AND effective_date > @EndDate
AND LagEffective BETWEEN @StartDate AND @EndDate
UNION ALL
SELECT 'Trailing' AS RangeStatus, *
FROM cteLeadLag
WHERE status_id = 1
AND effective_date < @EndDate
AND LeadEffective BETWEEN @StartDate AND @EndDate
I first select all records with their leading and lagging Dates and then I perform your checks on the inclusion in the desired timespan.
Try with this, self-explanatory. Responds to this part of your question:
I want to answer to the question "Get all companies that have been at
least for some point in status 1 inside the time period 01/01/2017 -
31/12/2017"
- Case that you want to find those id's that have been in any moment in status 1 and have records in the period requested:
SELECT *
FROM company_status_history
WHERE id IN
( SELECT Id
FROM company_status_history
WHERE status_id=1 )
AND effective_date BETWEEN '2017-01-01' AND '2017-12-31'
- Case that you want to find id's in status 1 and inside the period:
SELECT *
FROM company_status_history
WHERE status_id=1
AND effective_date BETWEEN '2017-01-01' AND '2017-12-31'
