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[Class statistics] Improved performance of "Courses of Class" tab
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Closes #4715
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@santeri0200
santeri0200 committed Jan 27, 2025
1 parent 5ce3337 commit d6765bd
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Showing 2 changed files with 79 additions and 86 deletions.
57 changes: 26 additions & 31 deletions services/backend/src/services/populations/bottlenecksOf.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -22,39 +22,34 @@ const getStudentsAndCourses = async (
studentNumbers: string[] | null,
courseCodes: string[] | undefined
): Promise<[number, CoursesQueryResult, EnrollmentsQueryResult]> => {
if (!studentNumbers) {
const { months, studyRights, startDate, endDate, exchangeStudents, nondegreeStudents, transferredStudents } = params
const studentnumbers =
selectedStudents ??
(await getStudentNumbersWithAllStudyRightElements({
studyRights,
startDate,
endDate,
exchangeStudents,
nondegreeStudents,
transferredOutStudents: transferredStudents,
}))

const allStudents = studentnumbers.length
const courses = await findCourses(studentnumbers, dateMonthsFromNow(startDate, months), courseCodes)
const foundCourseCodes = Object.keys(keyBy(courses, 'code'))
const filteredCourseCodes = courseCodes?.filter(code => !foundCourseCodes.includes(code))
const courseEnrollments = await findCourseEnrollments(
studentnumbers,
dateMonthsFromNow(startDate, months),
filteredCourseCodes
)

return [allStudents, courses, courseEnrollments]
}
const { months, studyRights, startDate, endDate, exchangeStudents, nondegreeStudents, transferredStudents } = params

const studentnumbers =
studentNumbers ??
selectedStudents ??
(await getStudentNumbersWithAllStudyRightElements({
studyRights,
startDate,
endDate,
exchangeStudents,
nondegreeStudents,
transferredOutStudents: transferredStudents,
}))

const allStudents = studentnumbers.length

const { months, startDate } = params
const beforeDate = months && startDate ? dateMonthsFromNow(startDate, months) : new Date()
const allStudents = studentNumbers.length
const courses = await findCourses(studentNumbers, beforeDate, courseCodes)
const foundCourseCodes = Object.keys(keyBy(courses, 'code'))
const courses = !studentNumbers
? await findCourses(studentnumbers, dateMonthsFromNow(startDate, months), courseCodes)
: await findCourses(studentnumbers, beforeDate, courseCodes)

const foundCourseCodes = [...new Set(courses.map(({ code }) => code))].toSorted()
const filteredCourseCodes = courseCodes?.filter(code => !foundCourseCodes.includes(code))
const courseEnrollments = await findCourseEnrollments(studentNumbers, beforeDate, filteredCourseCodes)
const courseEnrollments = filteredCourseCodes?.length
? !studentNumbers
? await findCourseEnrollments(studentnumbers, dateMonthsFromNow(startDate, months), filteredCourseCodes)
: await findCourseEnrollments(studentnumbers, beforeDate, filteredCourseCodes)
: []

return [allStudents, courses, courseEnrollments]
}
Expand Down Expand Up @@ -149,7 +144,7 @@ export const bottlenecksOf = async (query: Query, studentNumbers: string[] | nul
})
}
if ('credits' in course) {
course.credits.forEach(credit => {
course.credits?.forEach(credit => {
const { studentnumber, passingGrade, improvedGrade, failingGrade, grade, date } = parseCreditInfo(credit)
if (query?.selectedStudents?.includes(studentnumber) || !query?.selectedStudents) {
const semester = getPassingSemester(startYear, date)
Expand Down
108 changes: 53 additions & 55 deletions services/backend/src/services/populations/shared.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -448,24 +448,6 @@ export const formatStudentsForApi = (
}
}

const getSubstitutions = async (codes: string[]) => {
const courses = await Course.findAll({
attributes: ['code', 'substitutions'],
where: {
code: {
[Op.iLike]: { [Op.any]: codes },
},
},
raw: true,
})

const substitutions = [
...new Set(courses.flatMap(({ code, substitutions }) => [code, ...Object.values(substitutions).flat()])),
]

return substitutions
}

export type EnrollmentsQueryResult = Array<{
code: string
name: Name
Expand All @@ -482,12 +464,10 @@ export type CoursesQueryResult = Array<
}
>

// This duplicate code is added here to ensure that we get the enrollments in cases no credits found for the selected students
export const findCourseEnrollments = async (studentNumbers: string[], beforeDate: Date, courses: string[] = []) => {
const courseCodes = courses.length === 0 ? ['DUMMY'] : await getSubstitutions(courses)
const result: EnrollmentsQueryResult = await sequelize.query(
`
SELECT DISTINCT ON (course.id)
SELECT DISTINCT
course.code,
course.name,
course.substitutions,
Expand All @@ -496,24 +476,32 @@ export const findCourseEnrollments = async (studentNumbers: string[], beforeDate
FROM course
INNER JOIN (
SELECT
course_id,
ARRAY_AGG(JSON_BUILD_OBJECT(
course_code,
ARRAY_AGG(JSONB_BUILD_OBJECT(
'studentnumber', studentnumber,
'state', state,
'enrollment_date_time', enrollment_date_time
)) AS data
FROM enrollment
WHERE enrollment.studentnumber IN (:studentnumbers) AND enrollment.enrollment_date_time < :beforeDate AND enrollment.state = :enrollmentState
GROUP BY enrollment.course_id
) enrollment ON enrollment.course_id = course.id
WHERE :skipCourseCodeFilter OR course.code IN (:courseCodes)
WHERE studentnumber IN (:studentnumbers)
AND enrollment_date_time < :beforeDate
AND state = :enrollmentState
GROUP BY course_code
) AS enrollment
ON enrollment.course_code = course.code
WHERE course.code IN (:courseCodes)
OR (
SELECT
JSONB_AGG(DISTINCT alt_code)
FROM course, LATERAL JSONB_ARRAY_ELEMENTS(substitutions) as alt_code
WHERE code IN (:courseCodes)
) ? course.code
`,
{
replacements: {
studentnumbers: studentNumbers.length > 0 ? studentNumbers : ['DUMMY'],
beforeDate,
courseCodes,
skipCourseCodeFilter: courses.length === 0,
courseCodes: courses.length ? courses : ['DUMMY'],
enrollmentState: EnrollmentState.ENROLLED,
},
type: QueryTypes.SELECT,
Expand All @@ -523,57 +511,67 @@ export const findCourseEnrollments = async (studentNumbers: string[], beforeDate
}

export const findCourses = async (studentNumbers: string[], beforeDate: Date, courses: string[] = []) => {
const courseCodes = courses.length === 0 ? ['DUMMY'] : await getSubstitutions(courses)
const result: CoursesQueryResult = await sequelize.query(
return sequelize.query(
`
SELECT DISTINCT ON (course.id)
SELECT
course.code,
course.name,
course.substitutions,
course.main_course_code,
credit.data AS credits,
enrollment.data AS enrollments
enrollment.data AS enrollments,
credit.data AS credits
FROM course
INNER JOIN (
LEFT JOIN (
SELECT
course_code,
ARRAY_AGG(JSONB_BUILD_OBJECT(
'studentnumber', studentnumber,
'state', state,
'enrollment_date_time', enrollment_date_time
)) AS data
FROM enrollment
WHERE studentnumber IN (:studentnumbers)
AND enrollment_date_time < :beforeDate
AND state = :enrollmentState
GROUP BY course_code
) AS enrollment
ON enrollment.course_code = course.code
LEFT JOIN (
SELECT
course_code,
ARRAY_AGG(JSON_BUILD_OBJECT(
ARRAY_AGG(JSONB_BUILD_OBJECT(
'grade', grade,
'student_studentnumber', student_studentnumber,
'attainment_date', attainment_date,
'credittypecode', credittypecode,
'course_code', course_code
)) AS data
FROM credit
WHERE student_studentnumber IN (:studentnumbers) AND attainment_date < :beforeDate
GROUP BY credit.course_code
) credit ON credit.course_code = course.code
LEFT JOIN (
SELECT
course_id,
ARRAY_AGG(JSON_BUILD_OBJECT(
'studentnumber', studentnumber,
'state', state,
'enrollment_date_time', enrollment_date_time
)) AS data
FROM enrollment
WHERE enrollment.studentnumber IN (:studentnumbers) AND enrollment.enrollment_date_time < :beforeDate AND enrollment.state = :enrollmentState
GROUP BY enrollment.course_id
) enrollment ON enrollment.course_id = course.id
WHERE :skipCourseCodeFilter OR course.code IN (:courseCodes)
WHERE student_studentnumber IN (:studentnumbers)
AND attainment_date < :beforeDate
GROUP BY course_code
) AS credit
ON credit.course_code = course.code
WHERE :skipCourseCodeFilter
OR course.code IN (:courseCodes)
OR (
SELECT
JSONB_AGG(DISTINCT alt_code)
FROM course, LATERAL JSONB_ARRAY_ELEMENTS(substitutions) as alt_code
WHERE code IN (:courseCodes)
) ? course.code
`,
{
replacements: {
studentnumbers: studentNumbers.length > 0 ? studentNumbers : ['DUMMY'],
beforeDate,
courseCodes,
courseCodes: courses.length ? courses : ['DUMMY'],
skipCourseCodeFilter: courses.length === 0,
enrollmentState: EnrollmentState.ENROLLED,
},
type: QueryTypes.SELECT,
}
)
return result
) as Promise<CoursesQueryResult>
}

export const parseCreditInfo = (credit: CreditPick) => {
Expand Down

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