MS SQL get aggregate datetime difference by status - sql

Question

I have below table in sql.
======================================================
UnitID Status DateTime Value
======================================================
101 A 01/12/2017 00:02:10 10
101 A 01/12/2017 00:02:40 25
101 A 01/12/2017 00:03:20 18
101 B 01/12/2017 00:03:55 30
101 B 01/12/2017 00:04:05 10
101 B 01/12/2017 00:04:30 20
101 B 01/12/2017 00:04:50 10
101 A 01/12/2017 00:05:00 28
101 A 01/12/2017 00:05:50 18
101 A 01/12/2017 00:06:20 18
102 A 01/12/2017 00:02:10 10
102 A 01/12/2017 00:02:40 25
102 A 01/12/2017 00:03:20 18
102 B 01/12/2017 00:03:55 30
102 B 01/12/2017 00:04:05 10
102 B 01/12/2017 00:04:30 20
102 B 01/12/2017 00:04:50 10
102 A 01/12/2017 00:05:00 28
102 A 01/12/2017 00:05:50 18
102 A 01/12/2017 00:06:20 18
From this table i need below mention output.
===========================================
UnitID StatusA StatusB MaxValue
===========================================
101 02:30 00:55 30
102 02:30 00:55 30
what i need is the total time difference by status. so how could i achieve this in mssql query. so here 02:30 is time duration for status "A" in the table.
Thank you in advanced.

Answer 1

As far as I know you cannot have status in different columns, only by row.
SELECT [UnitID], [Status], MAX([DateTime]) - MIN([DateTime]), MAX([Value])
FROM [theTable]
GROUP BY [UnitID], [Status]
Output would be like
101 A 02:30 30
101 B 00:55 30
102 A 02:30 30
102 B 00:55 30
If you have fixed states of A and B you can go messy and do this:
SELECT UnitID, A, B, MaxValue
FROM
(
SELECT [UnitID], MAX([DateTime]) - MIN([DateTime]) AS A, null AS B, MAX([Value]) AS MaxValue
FROM [theTable]
WHERE Status = 'A'
GROUP BY [UnitID]
UNION ALL
SELECT [UnitID], null, MAX([DateTime]) - MIN([DateTime]), MAX([Value])
FROM [theTable]
WHERE Status = 'B'
GROUP BY [UnitID]
) x

Answer 2

You can do what you need with the following query. I tried to separate each step on different CTE's so you can see step by step how to get to your result. LAG will retrieve the previous row value (spliting by the PARTITION BY columns and ordering by the ORDER BY).
;WITH LaggedValues AS
(
SELECT
M.UnitID,
M.Status,
M.DateTime,
LaggedDateTime = LAG(M.DateTime) OVER (PARTITION BY M.UnitID ORDER BY M.DateTime ASC),
LaggedStatus = LAG(M.Status) OVER (PARTITION BY M.UnitID ORDER BY M.DateTime ASC)
FROM
Measures AS M
),
TimeDifferences AS
(
SELECT
T.*,
SecondDifference = CASE
WHEN T.Status = T.LaggedStatus THEN DATEDIFF(SECOND, T.LaggedDateTime, T.DateTime) END
FROM
LaggedValues AS T
),
TotalsByUnitAndStatus AS
(
SELECT
T.UnitID,
T.Status,
SecondDifference = SUM(T.SecondDifference)
FROM
TimeDifferences AS T
GROUP BY
T.UnitID,
T.Status
),
TotalsByUnit AS -- Conditional aggregation (alternative to PIVOT)
(
SELECT
T.UnitID,
StatusA = MAX(CASE WHEN T.Status = 'A' THEN T.SecondDifference END),
StatusB = MAX(CASE WHEN T.Status = 'B' THEN T.SecondDifference END)
FROM
TotalsByUnitAndStatus AS T
GROUP BY
T.UnitID
)
SELECT
T.UnitID,
StatusA = CONVERT(VARCHAR(10), T.StatusA / 60) + ':' + CONVERT(VARCHAR(10), T.StatusA % 60),
StatusB = CONVERT(VARCHAR(10), T.StatusB / 60) + ':' + CONVERT(VARCHAR(10), T.StatusB % 60)
FROM
TotalsByUnit AS T

Answer 3

You can get the difference for each group:
select unitid, status, min(datetime) as mindt, max(datetime) as maxdt, max(value) as maxvalue
from (select t.*,
row_number() over (partition by unitid order by datetime) as seqnum,
row_number() over (partition by unitid, status order by datetime) as seqnum_s
from t
) t
group by unitid, status, (seqnum - seqnum_s);
This solves the "groups-and-islands" problem. Now you can get the information you want using conditional aggregation:
with t as (
select unitid, status, min(datetime) as mindt, max(datetime) as maxdt, max(value) as maxvalue
from (select t.*,
row_number() over (partition by unitid order by datetime) as seqnum,
row_number() over (partition by unitid, status order by datetime) as seqnum_s
from t
) t
group by unitid, status, (seqnum - seqnum_s)
)
select unitid,
sum(case when status = 'A' then datediff(minute, mindt, maxdt) end) as a_minutes,
sum(case when status = 'b' then datediff(minute, mindt, maxdt) end) as a_minutes,
max(maxvalue)
from t
group by unitid;
I'll leave it up to you to convert the minutes back to times.