Function headless_lms_models::user_course_instance_exercise_service_variables::get_all_user_variables_for_user_and_course_instance_and_exercise_type

pub async fn get_all_user_variables_for_user_and_course_instance_and_exercise_type(
    conn: &mut PgConnection,
    user_id: Uuid,
    course_instance_id: Uuid,
    exercise_type: &str
) -> ModelResult<Vec<UserCourseInstanceExerciseServiceVariable>>