Sie können es so machen, diese Abfrage füllt zuerst die Klassenzimmer mit der größten Kapazität:
DECLARE @School TABLE (School_Id INT,Course_Id
VARCHAR(50), Total_Students INT)
DECLARE @Class TABLE (School_Id INT,Course_Id
VARCHAR(50), Class_ID VARCHAR(50), Capacity INT)
INSERT @School VALUES
(1, 'Acct101' ,150),
(1, 'Acct102' ,100),
(2, 'Acct101' ,110),
(2, 'Acct102' ,130)
INSERT @Class VALUES
(1, 'Acct101' ,'A1' ,65),
(1, 'Acct101' ,'A2' ,50),
(1, 'Acct101' ,'A3' ,70),
(1, 'Acct102' ,'Ab1' ,100),
(1, 'Acct102' ,'Ab2' ,100),
(2, 'Acct101' ,'B1' ,80),
(2, 'Acct101' ,'B2' ,90)
;WITH y AS (
SELECT a.*,
ROW_NUMBER() OVER
(PARTITION BY a.School_ID, a.Course_ID ORDER BY a.Capacity DESC)
CapacitiyOrderPerSchoolAndCourse,
SUM(a.Capacity) OVER
(PARTITION BY a.School_ID, a.Course_ID)
TotalCapacityForSchoolAndCourse,
b.Total_Students TotalParticipants
FROM @Class a
JOIN @School b ON
b.School_Id = a.School_Id
AND b.Course_Id = a.Course_Id
), z AS(
SELECT x.School_Id,
x.Course_Id,
y.TotalCapacityForSchoolAndCourse,
y.TotalParticipants,
CASE WHEN y.TotalParticipants < SUM(x.Capacity) THEN
y.TotalParticipants
ELSE
SUM(x.Capacity)
END NumberOfStudentsInClasses,
MIN(y.Capacity) ClassCapacity,
y.Class_ID ClassName,
MIN(y.Capacity) -
CASE WHEN y.TotalParticipants - SUM(x.Capacity) < 0 THEN
ABS(y.TotalParticipants - SUM(x.Capacity))
ELSE
0
END StudentsInClass
FROM y
JOIN y x ON x.School_Id = y.School_Id
AND x.Course_Id = y.Course_Id
AND x.CapacitiyOrderPerSchoolAndCourse
<= y.CapacitiyOrderPerSchoolAndCourse
GROUP BY x.School_Id,
x.Course_Id,
y.CapacitiyOrderPerSchoolAndCourse,
y.Class_ID,
y.TotalCapacityForSchoolAndCourse,
y.TotalParticipants
)
SELECT
z.School_Id,
z.Course_Id,
z.TotalCapacityForSchoolAndCourse,
z.TotalParticipants,
z.ClassName,
z.ClassCapacity,
CASE WHEN StudentsInClass < 0 THEN
0
ELSE
StudentsInClass
END StudentsInClass
FROM z
Wenn Sie möchten, dass jedes Klassenzimmer eine bestimmte Anzahl von Schülern hat, können Sie es so machen (es weist jedem Klassenzimmer eine Anzahl von Schülern entsprechend seiner Kapazität zu):
;WITH y AS (
SELECT a.*,
SUM(a.Capacity) OVER
(PARTITION BY a.School_ID, a.Course_ID)
AS TotalCapacityForSchoolAndCourse,
b.Total_Students TotalParticipants
FROM @Class a
JOIN @School b ON
b.School_Id = a.School_Id
AND b.Course_Id = a.Course_Id
), z AS(
SELECT y.School_Id,
y.Course_Id,
y.TotalCapacityForSchoolAndCourse,
y.TotalParticipants,
MIN(y.Capacity) ClassCapacity,
y.Class_ID,
MIN(y.Capacity) * 1.0 / y.TotalCapacityForSchoolAndCourse
AS PercentOfCapacity,
ROUND(
MIN(y.Capacity) * 1.0 / y.TotalCapacityForSchoolAndCourse
* TotalParticipants
, 0, 0)
AS NumberOfStudents
FROM y
GROUP BY y.School_Id,
y.Course_Id,
y.Class_ID,
y.TotalCapacityForSchoolAndCourse,
y.TotalParticipants
)
, i AS(
SELECT
z.School_Id,
z.Course_Id,
z.TotalCapacityForSchoolAndCourse,
z.TotalParticipants,
z.Class_ID,
z.ClassCapacity,
PercentOfCapacity,
NumberOfStudents,
SUM(NumberOfStudents) OVER
(PARTITION BY z.School_Id, z.Course_Id)
AS SumNumberOfStudents,
ROW_NUMBER() OVER
(PARTITION BY z.School_Id, z.Course_Id
ORDER BY NumberOfStudents)
AS ClassWithSmallestCapacity
FROM z
), j AS(
SELECT i.School_Id,
i.Course_Id,
i.TotalCapacityForSchoolAndCourse,
i.TotalParticipants,
i.Class_ID,
i.ClassCapacity,
i.PercentOfCapacity,
i.NumberOfStudents,
i.NumberOfStudents +
CASE WHEN ClassWithSmallestCapacity = 1 THEN
TotalParticipants - SumNumberOfStudents
ELSE 0
END AS NumberOfStudents2
FROM i
)
SELECT *
FROM j
