Many-to-many (ERD)

title {label: "Many-to-many via junction", size: "16"}

[Student] {bgcolor: "#d0e0d0"}
  *student_id {label: "int, not null"}
  name {label: "varchar, not null"}

[Course] {bgcolor: "#d0e0d0"}
  *course_id {label: "int, not null"}
  title {label: "varchar, not null"}
  credits {label: "int, null"}

[Enrollment] {bgcolor: "#fcecec"}
  *+student_id {label: "int, not null"}
  *+course_id {label: "int, not null"}
  enrolled_at {label: "date, not null"}
  grade {label: "varchar, null"}

Student 1--* Enrollment
Course 1--* Enrollment