如何使用Go语言开发点餐系统的评价管理功能

type Order struct {
    ID       int
    UserID   int
    ShopID   int
    Dishes   []Dish
    Comments []Comment
}

type Dish struct {
    ID       int
    Name     string
    Price    float64
    Quantity int
}

type User struct {
    ID       int
    Username string
    Phone    string
}

type Comment struct {
    ID      int
    OrderID int
    Content string
    Reply   Reply
}

type Reply struct {
    ID      int
    CommentID int
    Content string
}

func AddComment(OrderID int, content string) error {
    // 首先查询订单是否存在
    order, err := GetOrder(OrderID)
    if err != nil {
        return err
    }
    comment := Comment{
        ID:      generateCommentID(),
        OrderID: OrderID,
        Content: content,
    }
    order.Comments = append(order.Comments, comment)
    // 更新订单的评价信息到数据库
    err = UpdateOrder(order)
    if err != nil {
        return err
    }
    return nil
}

func AddReply(CommentID int, content string) error {
    // 首先查询评价是否存在
    comment, err := GetComment(CommentID)
    if err != nil {
        return err
    }
    reply := Reply{
        ID:        generateReplyID(),
        CommentID: CommentID,
        Content:   content,
    }
    comment.Reply = reply
    // 更新评价的回复信息到数据库
    err = UpdateComment(comment)
    if err != nil {
        return err
    }
    return nil
}

func GetCommentAndReply(OrderID int) (Comment, Reply, error) {
    comment, err := GetCommentByOrderID(OrderID)
    if err != nil {
        return Comment{}, Reply{}, err
    }
    reply, err := GetReplyByCommentID(comment.ID)
    if err != nil {
        return comment, Reply{}, err
    }
    return comment, reply, nil
}