extend schema
    @link(
        url: "https://specs.apollo.dev/federation/v2.3",
        import: ["@key", "@external", "@requires"]
     )

type Query {
  courseRating(courseId: ID!): [CourseRating]
}

type CourseRating @key(fields: "courseId") {
  courseId: ID!
  rating: Float
  comments: String
}

type Enrollment @key(fields: "studentId courseId") {
  studentId: ID!
  courseId: ID!
  rating: CourseRating
}