SQL Server Select one column by aggregate but not another - sql

Question

Not good with sql. Forgive me if the question isn't 100% clear. Here is my query
SELECT
MAX(PatientId),
[Date],
[Time],
CASE WHEN MAX(CAST(HealthScoreSkipped as INT)) = 1
THEN '--'
ELSE MAX(DailyHealthScore)
END DailyHealthScore,
ProtocolGroupName,
MAX(BloodPressure) BloodPressure,
MAX(SystolicAlert) SystolicAlert,
MAX(DiastolicAlert) DiastolicAlert,
MAX(BloodPressureSkipped) BloodPressureSkipped,
MAX(Pulse) Pulse,
MAX(PulseAlert) PulseAlert,
MAX(PulseSkipped) PulseSkipped,
MAX(BloodSugar) BloodSugar,
MAX(BloodSugarAlert) BloodSugarAlert,
MAX(BloodSugarSkipped) BloodSugarSkipped,
MAX(Steps) Steps,
MAX(StepsAlert) StepsAlert,
MAX(StepsSkipped) StepsSkipped,
MAX(O2) O2,
MAX(O2Alert) O2Alert,
MAX(O2Skipped) O2Skipped,
MAX(Weight) Weight,
MAX(WeightAlert) WeightAlert,
#BaselineWeight AS BaselineWeight,
MAX(WeightSkipped) WeightSkipped,
MAX(Temperature) Temperature,
MAX(TemperatureAlert) TemperatureAlert,
MAX(TemperatureUnit) TemperatureUnit,
MAX(TemperatureSkipped) TemperatureSkipped,
MAX(PEF) PEF,
MAX(PEFAlert) PEFAlert,
MAX(PEFSkipped) PEFSkipped,
MAX(FEV1) FEV1,
MAX(FEV1Alert) FEV1Alert,
MAX(FEV1Skipped) FEV1Skipped,
MAX(FEVRatio) FEVRatio,
MAX(FEVRatioAlert) FEVRatioAlert,
MAX(FEVRatioSkipped) FEVRatioSkipped,
#SpiroEnabled SpiroEnabled
FROM #bioAndScores
GROUP BY PatientId, Date, Time, ProtocolGroupName
The problem here is on the lines
MAX(Steps) Steps,
MAX(StepsAlert) StepsAlert
I want to select the max Steps but the stepalert value that goes with that row not the max of the stepAlert.

Answer 1

You can create a sub query in the select statement to get the steps alert that corresponds to your step.
something along the lines of the below (note that I'm not sure why you are grouping by patientId, if you are taking the max(patientId) if you do want to group by patient id, the where clause of the sub query should also match on patient Id
SELECT
MAX(bas.PatientId),
bas.[Date],
bas.[Time],
bas.ProtocolGroupName,
.
.
.
MAX(bas.Steps) Steps,
--sub query to get the StepsAlert that corresponds to max steps
(SELECT
StepsAlert
FROM
#bioAndScores subBas
WHERE
--This is the important part of finding the match for Max Steps
MAX(bas.Steps) = subBas.Steps AND
--commented out because the MAX(PatientId) was ambiguous
--bas.PatientId = subBas.PatientId AND
bas.[Date] = subBas.[Date] AND
bas.[Time] = subBas.[Time] AND
bas.ProtocolGroupName = subBas.ProtocolGroupName) as StepsAlert
FROM
#bioAndScores as bas
GROUP BY
--PatientId,
bas.Date,
bas.Time,
bas.ProtocolGroupName

Answer 2

Remove the MAX() function from StepAlerts and add StepAlerts to your GROUP BY clause.
MAX(Steps) AS Steps,
StepsAlert AS StepsAlert
And in your GROUP BY:
GROUP BY PatientId, Date, Time, ProtocolGroupName, StepAlerts

Answer 3

Just add StepsAlert column to the group by clause and remove the MAX aggregate function.
GROUP BY PatientId, Date, Time, ProtocolGroupName,StepsAlert
I would suggest you go through this to better understand about how group by works.

Answer 4

You can do this using apply() to select the set of values that correspond to the highest Steps at the earliest StepsAlert like so:
select
PatientId
, [Date]
, [Time]
, DailyHealthScore = case
when MAX(CAST(HealthScoreSkipped as int))= 1 then '--'
else MAX(DailyHealthScore)
end
, ProtocolGroupName
, BloodPressure = MAX(BloodPressure)
, SystolicAlert = MAX(SystolicAlert)
, DiastolicAlert = MAX(DiastolicAlert)
, BloodPressureSkipped= MAX(BloodPressureSkipped)
, Pulse = MAX(Pulse)
, PulseAlert = MAX(PulseAlert)
, PulseSkipped = MAX(PulseSkipped)
, BloodSugar = MAX(BloodSugar)
, BloodSugarAlert = MAX(BloodSugarAlert)
, BloodSugarSkipped = MAX(BloodSugarSkipped)
, Steps = x.Steps
, StepsAlert = x.StepsAlert
, StepsSkipped = MAX(StepsSkipped)
, O2 = MAX(O2)
, O2Alert = MAX(O2Alert)
, O2Skipped = MAX(O2Skipped)
, Weight = MAX(Weight)
, WeightAlert = MAX(WeightAlert)
, BaselineWeight = #BaselineWeight
, WeightSkipped = MAX(WeightSkipped)
, Temperature = MAX(Temperature)
, TemperatureAlert = MAX(TemperatureAlert)
, TemperatureUnit = MAX(TemperatureUnit)
, TemperatureSkipped = MAX(TemperatureSkipped)
, PEF = MAX(PEF)
, PEFAlert = MAX(PEFAlert)
, PEFSkipped = MAX(PEFSkipped)
, FEV1 = MAX(FEV1)
, FEV1Alert = MAX(FEV1Alert)
, FEV1Skipped = MAX(FEV1Skipped)
, FEVRatio = MAX(FEVRatio)
, FEVRatioAlert = MAX(FEVRatioAlert)
, FEVRatioSkipped = MAX(FEVRatioSkipped)
, SpiroEnabled = #SpiroEnabled
from #bioAndScores b
cross apply (
select top 1
i.Steps
, i.StepsAlert
from #bioAndScores i
where b.PatientId = i.PatientId
and b.[Date] = i.[Date]
and b.[Time] = i.[Time]
and b.ProtocolGroupName = i.ProtocolGroupName
order by i.Steps desc, i.StepsAlert asc
) x
group by
PatientId
, date
, time
, ProtocolGroupName