Finding the T-SQL to return these values

Question

I'm trying to write a stored procedure that will return two calculated values for each record according to the rules below, but I haven't figured out how to structure the SQL to make it happen. I'm using SQL Server 2008.

First, the relevant tables, and the fields that matter to the problem.

ProductionRuns

 RunID (key, and RunID is given to the stored proc as its parameter)
 ContainerName
 ProductName
 TemplateID

TemplateMeasurements

 MeasurementTypeID
 TemplateID

SimpleBounds

 MeasurementTypeID
 TemplateID
 UpperBound
 LowerBound

ContainerBounds

 MeasurementTypeID
 TemplateID
 UpperBound
 LowerBound
 ContainerName

ProductBounds

 MeasurementTypeID
 TemplateID
 UpperBound
 LowerBound
 ProductName

And this is what I'm trying to return. I want to return a calculated upper bound and lower bound value for each TemplateMeasurements record that has a matching TemplateID with the ProductionRuns record that has the supplied runID.

The calculated upper and lower bounds basically get the tightest bound that can be obtained as a result of the simple, container and product bounds, if they qualify.

If a SimpleBounds record exists with the correct MeasurementTypeID and TemplateID, then that becomes one of the qualifying bounds for a particular MeasurementTypeID and record of TemplateMeasurements.

For a ContainerBound record to qualify, the TemplateID and MeasurementTypeID must match, but also the ContainerName must match the value for ContainerName in the ProductionRuns record. Also for ProductBounds, the same is true, but for ProductName.

For a particular MeasurementTypeID, take all the qualifying bounds, and find the least Upper Bound, and that will be the calculated Upper Bound that is to be returned. Find the greatest Lower Bound of the qualifiers and that will be the returned Lower Bound.

I have no idea how to put together SQL to do this however.

Also, if none of the three bound tables qualify for a particular MeasurementTypeID, then null could be returned.

My thought would be some kind of left outer join, but I'm not sure how to extend that to three tables that could all have null in the results.

Thanks for the help.

Answer 1

Thanks for leading me in the right direction. I had to fiddle with the problem for a while before I got it tweaked just right, but it works great now.

My final code and results:

 ALTER PROCEDURE [dbo].[GetBounds]
 @runID int
 AS
 BEGIN
    SET NOCOUNT ON;
    DECLARE @templateID int
    SET @templateID = (SELECT TOP(1) TemplateID 
    FROM ProductionRuns WHERE RunID = @runID);

    SELECT TM.MeasurementTypeID,

    CASE 
    WHEN MIN(SB.UpperBound) < MIN(PB.UpperBound) 
    AND MIN(SB.UpperBound) < MIN(CB.UpperBound) THEN MIN(SB.UpperBound)
    WHEN MIN(PB.UpperBound) < MIN(SB.UpperBound) 
    AND MIN(PB.UpperBound) < MIN(CB.UpperBound) THEN MIN(PB.UpperBound)
    WHEN MIN(CB.UpperBound) < MIN(SB.UpperBound) 
    AND MIN(CB.UpperBound) < MIN(PB.UpperBound) THEN MIN(CB.UpperBound)
    ELSE MIN(SB.UpperBound) 
    END AS 'UpperBound',

    CASE
    WHEN MAX(SB.LowerBound) > MAX(PB.LowerBound) 
    AND MAX(SB.LowerBound) > MAX(CB.LowerBound) THEN MAX(SB.LowerBound)
    WHEN MAX(PB.LowerBound) > MAX(SB.LowerBound) 
    AND MAX(PB.LowerBound) > MAX(CB.LowerBound) THEN MAX(PB.LowerBound)
    WHEN MAX(CB.LowerBound) > MAX(SB.LowerBound) 
    AND MAX(CB.LowerBound) > MAX(PB.LowerBound) THEN MAX(CB.LowerBound)
    ELSE MAX(SB.LowerBound)
    END AS 'LowerBound'

    FROM
    ProductionRuns PR
    INNER JOIN TemplateMeasurements TM ON
    TM.TemplateID = PR.TemplateID
    LEFT OUTER JOIN SimpleBounds SB ON
    SB.TemplateID = PR.TemplateID AND
    SB.MeasurementTypeID = TM.MeasurementTypeID
    LEFT OUTER JOIN ContainerBounds CB ON
    CB.TemplateID = PR.TemplateID AND
    CB.MeasurementTypeID = TM.MeasurementTypeID AND
    CB.ContainerName = PR.ContainerName
    LEFT OUTER JOIN ProductBounds PB ON
    PB.TemplateID = PR.TemplateID AND
    PB.MeasurementTypeID = TM.MeasurementTypeID AND
    PB.ProductName = PR.ProductName 

    WHERE TM.TemplateID = @templateID

    GROUP BY
    TM.MeasurementTypeID
 END

Partial results for a particular case, RunID = 3249 (TemplateID = 2)

MeasurementTypeID   UpperBound  LowerBound
2   NULL    NULL
11  4   2.5
18  30  1
20  40  10
33  99  0
36  200 140
42  120 32
...

Answer 2

I don't have time to test this right now, but hopefully this will get you pretty close:

SELECT
     PR.RunID,
     PR.TemplateID,
     CASE
          WHEN MAX(SB.LowerBound) > MAX(CB.LowerBound) AND
                      MAX(SB.LowerBound) > MAX(PB.LowerBound) THEN MAX(SB.LowerBound)
          WHEN MAX(CB.LowerBound) > MAX(PB.LowerBound) THEN MAX(CB.LowerBound)
          ELSE MAX(PB.LowerBound)
     END AS LowerBound,
     CASE
          WHEN MIN(SB.UpperBound) < MIN(CB. UpperBound) AND
                      MIN(SB. UpperBound) < MIN(PB. UpperBound) THEN MIN(SB. UpperBound)
          WHEN MIN(CB. UpperBound) < MIN(PB. UpperBound) THEN MIN(CB. UpperBound)
          ELSE MIN(PB. UpperBound)
     END
FROM
     ProductionRuns PR
INNER JOIN TemplateMeasurements TM ON
      TM.TemplateID = PR.TemplateID
LEFT OUTER JOIN SimpleBounds SB ON
     SB.TemplateID = PR.TemplateID AND
     SB.MeasurementTypeID = TM.MeasurementTypeID
LEFT OUTER JOIN ContainerBounds CB ON
     CB.TemplateID = PR.TemplateID AND
     CB.MeasurementTypeID = TM.MeasurementTypeID AND
     CB.ContainerName = PR.ContainerName
LEFT OUTER JOIN ProductBounds PB ON
     PB.TemplateID = PR.TemplateID AND
     PB.MeasurementTypeID = TM.MeasurementTypeID AND
     PB.ProductName = PR.ProductName
GROUP BY
     PR.RunID,
     PR.TemplateID

Answer 3

You've got other answers already that should work, but in my opinion this type of UNIONed inner query can result in the cleanest-looking, most-maintainable way to collapse a horizontal hierarchy into a vertical one, which is basically your problem:

SELECT MIN(iq.upperbound), MAX(iq.lowerbound)
FROM TemplateMeasurements tm
    INNER JOIN ProductionRuns pr ON tm.TemplateID = pr.TemplateID
    LEFT JOIN
    (
    SELECT sb.UpperBound, sb.LowerBound, sb.MeasurementTypeID, '' as Name, 'sb' as Type, sb.TemplateID
    FROM SimpleBounds sb 
    UNION ALL
    SELECT cb.UpperBound, cb.LowerBound, cb.MeasurementTypeID, cb.ContainerName as Name, 'cb' as Type, cb.TemplateID
    FROM ContainerBounds cb 
    UNION ALL
    SELECT pb.UpperBound, pb.LowerBound, pb.MeasurementTypeID, pb.ProductName as Name, 'pb' as Type, pb.TemplateID
    FROM ProductBounds pb 
    ) iq ON iq.MeasurementTypeID = tm.MeasurementTypeID 
        AND iq.TemplateID = tm.TemplateID 
        AND iq.Name = 
            CASE iq.Type 
             WHEN 'sb' THEN iq.Name 
             WHEN 'cb' THEN pr.ContainerName 
             WHEN 'pb' THEN pr.ProductName 
            END
    WHERE pr.RunID = @runid
    GROUP BY tm.TemplateID, tm.MeasurementTypeID

Answer 4

Not to take away from Tom H.'s answer, but you might also consider approaching this problem with unions instead of joins to help split up the different upper/lower rules. It depends on how you think the queries will need to change (if at all) in the future.

The query ends up looking cleaner, especially without all the CASE rules, but it might not be as useful in cases when TemplateMeasurement rows don't exist.

SELECT RunID, TemplateID, MIN(UpperBound), MAX(LowerBound)
FROM

  (SELECT PR.RunID, SB.TemplateID, SB.UpperBound, SB.LowerBound
  FROM SimpleBounds SB
  INNER JOIN TemplateMeasurements TM
      ON  SB.TemplateID = TM.TemplateID
      AND SB.MeasurementTypeID = TM.MeasurementTypeID
  INNER JOIN ProductionRuns PR
      ON  TM.TemplateID = PR.TemplateID)

UNION

  (SELECT PR.RunID, CB.TemplateID, CB.UpperBound, CB.LowerBound
  FROM ContainerBounds CB
  INNER JOIN TemplateMeasurements TM
      ON  CB.TemplateID = TM.TemplateID
      AND CB.MeasurementTypeID = TM.MeasurementTypeID
  INNER JOIN ProductionRuns PR
      ON  TM.TemplateID = PR.TemplateID
      AND CB.ContainerName = PR.ContainerName)

UNION

  (SELECT PR.RunID, PB.TemplateID, PB.UpperBound, PB.LowerBound
  FROM ProductBounds PB
  INNER JOIN TemplateMeasurements TM
      ON  PB.TemplateID = TM.TemplateID
      AND PB.MeasurementTypeID = TM.MeasurementTypeID
  INNER JOIN ProductionRuns PR
      ON  TM.TemplateID = PR.TemplateID
      AND PB.ProductName = PR.ProductName)

GROUP BY RunID, TemplateID