Go语言开发点餐系统中的会员等级功能实现方法

CREATE TABLE IF NOT EXISTS members (
    id INT PRIMARY KEY,
    name VARCHAR(100),
    level INT,
    points INT
);

func registerMember(name string) error {
    // 生成新的会员ID
    id := generateMemberID()
    
    // 插入会员信息到数据库
    _, err := db.Exec("INSERT INTO members (id, name, level, points) VALUES (?, ?, ?, ?)", id, name, 1, 0)
    if err != nil {
        return err
    }

    return nil
}

func addPointsToMember(id int, amount float64) error {
    // 根据会员ID查询当前积分
    var points int
    err := db.QueryRow("SELECT points FROM members WHERE id = ?", id).Scan(&points)
    if err != nil {
        return err
    }

    // 计算新的积分
    newPoints := points + int(amount)
    
    // 更新积分到数据库
    _, err = db.Exec("UPDATE members SET points = ? WHERE id = ?", newPoints, id)
    if err != nil {
        return err
    }

    return nil
}

func updateMemberLevel() error {
    // 查询所有会员信息
    rows, err := db.Query("SELECT id, points FROM members")
    if err != nil {
        return err
    }
    defer rows.Close()

    for rows.Next() {
        var id, points int
        err = rows.Scan(&id, &points)
        if err != nil {
            return err
        }

        // 根据积分判断会员等级
        level := calculateMemberLevel(points)

        // 更新等级到数据库
        _, err = db.Exec("UPDATE members SET level = ? WHERE id = ?", level, id)
        if err != nil {
            return err
        }
    }

    return nil
}

func getMemberDiscountLevel(id int) float64 {
    // 查询会员等级
    var level int
    err := db.QueryRow("SELECT level FROM members WHERE id = ?", id).Scan(&level)
    if err != nil {
        return 0.0
    }

    // 根据会员等级返回不同的折扣级别
    switch level {
    case 1:
        return 0.9
    case 2:
        return 0.8
    case 3:
        return 0.7
    default:
        return 1.0
    }
}