User
    plugin         Text
    ident          Text
    matrikelnummer Text Maybe
    email          Text
    displayName    Text
    maxFavourites  Int   default=12
    theme          Theme default='default'
    UniqueAuthentication plugin ident
    UniqueEmail email
UserAdmin
    user   UserId
    school SchoolId
UserLecturer
    user   UserId
    school SchoolId
    UniqueSchoolLecturer user school
StudyFeatures
    user          UserId
    degree        StudyDegreeId
    field         StudyTermsId
    type          StudyFieldType
    semester      Int
    UniqueUserSubject user degree field
StudyDegree
    key           Int
    shorthand     Text Maybe
    name          Text Maybe
    Primary key
StudyTerms
    key           Int
    shorthand     Text Maybe
    name          Text Maybe
    Primary key
Term json
    name          TermIdentifier -- unTermKey :: TermId -> TermIdentifier
    start         Day            -- TermKey   :: TermIdentifier -< TermId
    end           Day
    holidays      [Day]
    lectureStart  Day 
    lectureEnd    Day 
    active        Bool    
    Primary name       -- newtype Key Term = TermKey { unTermKey :: TermIdentifier }
    deriving Show      -- type TermId = Key Term
School json
    name          Text 
    shorthand     Text
    UniqueSchool name
    deriving Eq    
DegreeCourse json
    course       CourseId
    degree       StudyDegreeId
    terms        StudyTermsId
    UniqueDegreeCourse course degree terms
Course 
    name             Text
    description      Html Maybe
    linkExternal     Text Maybe
    shorthand        Text
    term             TermId
    school           SchoolId
    capacity         Int Maybe
    -- canRegisterNow = maybe False (<= currentTime) registerFrom && maybe True (>= currentTime) registerTo
    registerFrom     UTCTime Maybe
    registerTo       UTCTime Maybe
    deregisterUntil  UTCTime Maybe
    registerSecret   Text Maybe        -- Falls ein Passwort erforderlich ist
    materialFree     Bool default=true
    CourseTermShort  term shorthand
CourseEdit
    user         UserId
    time         UTCTime
    course       CourseId
CourseFavourite
    user         UserId
    time         UTCTime
    course       CourseId
    UniqueCourseFavourite user course
Lecturer 
    user         UserId
    course       CourseId
    UniqueLecturer user course
CourseParticipant
    course          CourseId
    user            UserId
    registration    UTCTime
    UniqueParticipant user course
Sheet
    course          CourseId
    name            Text
    description     Html Maybe
    type            SheetType
    grouping        SheetGroup
    markingText     Html Maybe
    visibleFrom     UTCTime Maybe
    activeFrom      UTCTime
    activeTo        UTCTime
    hintFrom        UTCTime Maybe
    solutionFrom    UTCTime Maybe
    CourseSheet course name
SheetEdit
    user            UserId
    time            UTCTime
    sheet           SheetId
SheetCorrector
    user            UserId
    sheet           SheetId
    load            Load
    UniqueSheetCorrector user sheet
    deriving Show Eq Ord
SheetFile
    sheet           SheetId
    file            FileId
    type            SheetFileType
    UniqueSheetFile file sheet type
File        
    title           FilePath
    content         ByteString Maybe -- Nothing iff this is a directory
    modified        UTCTime
    deriving Show Eq
Submission
    sheet           SheetId
    ratingPoints    Points  Maybe
    ratingComment   Text    Maybe 
    ratingBy        UserId  Maybe
    ratingTime      UTCTime Maybe   
    deriving Show
SubmissionEdit
    user            UserId
    time            UTCTime
    submission      SubmissionId
SubmissionFile
    submission      SubmissionId
    file            FileId
    isUpdate        Bool         -- is this the file updated by a corrector (original will always be retained)
    isDeletion      Bool         -- only set if isUpdate is also set, but file was deleted by corrector
    UniqueSubmissionFile file submission isUpdate
    deriving Show
SubmissionUser
    user            UserId
    submission      SubmissionId
    UniqueSubmissionUser user submission
SubmissionGroup
    course          CourseId
    name            Text Maybe
SubmissionGroupEdit
    user            UserId
    time            UTCTime
    submissionGroup SubmissionGroupId
SubmissionGroupUser
    submissionGroup     SubmissionGroupId
    user                UserId
    UniqueSubmissionGroupUser submissionGroup   user
Tutorial json
    name        Text
    tutor       UserId
    course      CourseId
TutorialUser
    user        UserId
    tutorial    TutorialId
    UniqueTutorialUser user   tutorial
Booking
    term        TermId
    begin       UTCTime
    end         UTCTime
    weekly      Bool
    exceptions  [Day]    -- only if weekly, begin in exception
    bookedFor   RoomForId
    room        RoomId
BookingEdit
    user        UserId
    time        UTCTime
    boooking    BookingId
Room
    name        Text
    capacity    Int Maybe
    building    Text Maybe
-- BookingRoom
--    subject     RoomForId
--    room        RoomId
--    booking     BookingId
--    UniqueRoomCourse subject room   booking
+RoomFor
    course      CourseId
    tutorial    TutorialId
    exam        ExamId
-- data RoomFor = RoomForCourseSum CourseId | RoomForTutorialSum TutorialId ...
-- EXAMS ARE TODO:
Exam
    course              CourseId
    name                Text
    description         Text
    begin               UTCTime
    end                 UTCTime
    registrationBegin   UTCTime
    registrationEnd     UTCTime
    deregistrationEnd   UTCTime
    ratingVisible       Bool
    statisticsVisible   Bool
--ExamEdit
--    user                UserId
--    time                UTCTime
--    exam                ExamId
--ExamUser
--    user                UserId
--    examId              ExamId
--    -- CONTINUE HERE: Include rating in this table or separately?
--    UniqueExamUser user   examId
-- By default this file is used in Model.hs (which is imported by Foundation.hs)