CREATE TABLE LessonSchedule $($

HorseID SMALLINT UNSIGNED NOT NULL,

StudentID SMALLINT UNSIGNED,

LessonDateTime DATETIME NOT NULL,

PRIMARY KEY $($HorseID$,$ LessonDateTime$),$

FOREIGN KEY $($HorseID$)$ REFERENCE Horse$($ID$)$ ON DELETE CASCADE,

FOREIGN KEY $($StudentID$)$ REFERENCE Student$($ID$)$ ON DELETE SET NULL

$)$;