当尝试在切片指针上移动时，我一直收到此错误。

app/domain/repositories/class_repository.go:24: cannot range over classes (type *[]entities.Class)

我究竟做错了什么？

这是结构：

 package repositories

import (
    "mobifit/app/domain/entities"
)

type ClassRepository struct {
    *Repository
}

func (c *ClassRepository) ClassesForLastNDays(days int) *[]entities.Class {
    classes := new([]entities.Class)
    query := Select("*").
        From("Class").
        Where("VisibleAt > CURRENT_TIMESTAMP() - INTERVAL ? DAY").
        OrderBy("ClassTypeId").
        Sql()
    c.Repository.Select(classes, query, days)
    c.populateClassRelationships(classes)
    return classes
}

func (c *ClassRepository) populateClassRelationships(classes *[]entities.Class) {
    for i := range classes {  <<<<<<<<<<< Here is the problem
        class := classes[i]

        // ClassType
        c.Repository.GetById(class.ClassType, class.ClassTypeId)

        //Instructor
        c.Repository.GetById(class.Instructor, class.ClassType.InstructorId)

        // Equipment
        query := Select("E.*").
            From("Equipment E").
            Join("ClassEquipment CE on E.Id = CE.EquipmentId").
            Where("CE.ClassId = ?").
            Sql()
        c.Repository.Select(class.Equipment, query, class.Id)
    }
}

这是Class结构：

package entities

import (
    "time"
)

    type Class struct {
        Id                int
        ClassTypeId       int
        VideoPath         string
        VideoSize         int
        Duration          float64
        CreatedAt         time.Time
        VisibleAt         time.Time
        NoLongerVisibleAt time.Time

        // Relationships
        ClassType  ClassType
        Instructor User
        Equipment  []Equipment
    }