Sum Value if Two Specific Values Occur on the Same Day - tsql

Question

I've got a dataset that has species' harvest by weapon type by dates. Data set example below:
Species Total HarvestMonthDayYear WeaponID WeaponType
Deer 623 1/14/2017 1 Gun
Deer 10 1/14/2017 3 Reg Bow
Deer 15 1/14/2017 4 Crossbow
Deer 5 9/20/2017 4 Crossbow
Deer 9 9/21/2017 2 Muzzleloader
Deer 2 9/21/2017 3 Reg Bow
Deer 1 9/21/2017 4 Crossbow
Deer 1 9/21/2017 8 Shotgun
Deer 10 9/22/2017 1 Gun
Deer 1 9/22/2017 3 Reg Bow
What I would to accomplish is that when "Reg Bow" and "Crossbow" harvest on the same day, I would like to combine the results into one row named "Archery". And the final data set should look like:
Species Total HarvestMonthDayYear WeaponID WeaponType
Deer 623 1/14/2017 1 Gun
Deer 25 1/14/2017 10 Archery
Deer 5 9/20/2017 4 Crossbow
Deer 9 9/21/2017 2 Muzzleloader
Deer 3 9/21/2017 10 Archery
Deer 1 9/21/2017 8 Shotgun
Deer 10 9/22/2017 1 Gun
Deer 1 9/22/2017 2 Muzzleloader
Deer 1 9/22/2017 3 Reg Bow
On 01/14/2017 and 09/22/2017 - a regular bow and crossbow were used to harvest deer so I would like to combine those into one set - but on 09/20/2017 and 09/22/2017 - only a crossbow or regular bow was used so this result should be left as it.
Is this possible? I cannot think of a way to even begin to code this out.

Answer 1

You could phrase this as a union:
WITH cte AS (
SELECT Species, HarvestMonthDayYear, SUM(Total) AS Total
FROM yourTable
WHERE
WeaponType IN ('Reg Bow', 'Crossbow')
GROUP BY
Species, HarvestMonthDayYear
HAVING COUNT(DISTINCT WeaponType) = 2
)
SELECT
t1.Species, t1.Total, t1.HarvestMonthDayYear, t1.WeaponID, t1.WeaponType
FROM yourTable t1
LEFT JOIN cte t2
ON t1.Species = t2.Species AND
t1.HarvestMonthDayYear = t2.HarvestMonthDayYear
WHERE
t2.Species IS NULL OR
(t2.Species IS NOT NULL AND WeaponType NOT IN ('Reg Bow', 'Crossbow'))
UNION ALL
SELECT
Species, Total, HarvestMonthDayYear, 10, 'Archery'
FROM cte;
Demo here:
Rextester

Answer 2

Without TCE :
SELECT Species, HarvestMonthDayYear, SUM(Total) AS Total
, CASE WHEN WeaponType IN ('Reg Bow', 'Crossbow') THEN 10 ELSE WeaponID END AS WeaponID
, MAX(CASE WHEN WeaponType IN ('Reg Bow', 'Crossbow') THEN 'Archery' ELSE WeaponType END) AS WeaponType
FROM yourTable
GROUP BY
Species, HarvestMonthDayYear
, (CASE WHEN WeaponType IN ('Reg Bow', 'Crossbow') THEN 10 ELSE WeaponID END)

Answer 3

This should give you what you need, uses CTE but no UNION (tested) and is slightly more performant...
WITH HarvestResults AS
(
SELECT Species,
Total,
HarvestMonthDayYear,
CASE WHEN WeaponType IN ('Crossbow','Reg Bow') THEN 10 ELSE WeaponID END AS WeaponID,
WeaponType,
LAG(HarvestMonthDayYear,1) OVER(ORDER BY Species,HarvestMonthDayYear) AS PrevHarvestDate,
LEAD(HarvestMonthDayYear,1) OVER(ORDER BY Species,HarvestMonthDayYear) AS NextHarvestDate,
LAG(WeaponType,1) OVER(ORDER BY Species,HarvestMonthDayYear) AS PrevWeaponType,
LEAD(WeaponType,1) OVER(ORDER BY Species,HarvestMonthDayYear) AS NextWeponType
FROM dbo.Harvest
)
SELECT Species,
SUM(Total) AS TOTAL,
HarvestMonthDayYear,
CASE WHEN WeaponType IN ('Crossbow','Reg Bow')
AND ((PrevHarvestDate = HarvestMonthDayYear OR NextHarvestDate = HarvestMonthDayYear)
AND (PrevWeaponType IN ('Crossbow','Reg Bow') OR NextWeponType IN ('Crossbow','Reg Bow')))
THEN 10 ELSE WeaponID END AS WeaponID,
CASE WHEN WeaponType IN ('Crossbow','Reg Bow')
AND ((PrevHarvestDate = HarvestMonthDayYear OR NextHarvestDate = HarvestMonthDayYear)
AND (PrevWeaponType IN ('Crossbow','Reg Bow') OR NextWeponType IN ('Crossbow','Reg Bow')))
THEN 'Archery' ELSE WeaponType END AS WeaponType
FROM HarvestResults
GROUP BY Species,
HarvestMonthDayYear,
CASE WHEN WeaponType IN ('Crossbow','Reg Bow')
AND ((PrevHarvestDate = HarvestMonthDayYear OR NextHarvestDate = HarvestMonthDayYear)
AND (PrevWeaponType IN ('Crossbow','Reg Bow') OR NextWeponType IN ('Crossbow','Reg Bow')))
THEN 10 ELSE WeaponID END,
CASE WHEN WeaponType IN ('Crossbow','Reg Bow')
AND ((PrevHarvestDate = HarvestMonthDayYear OR NextHarvestDate = HarvestMonthDayYear)
AND (PrevWeaponType IN ('Crossbow','Reg Bow') OR NextWeponType IN ('Crossbow','Reg Bow')))
THEN 'Archery' ELSE WeaponType END
ORDER BY Species,
HarvestMonthDayYear,
WeaponID,
WeaponType;