Go语言开发点餐系统中的预约点餐功能实现方法

    func login(username string, passWord string) bool {
        // 在数据库中查询是否存在该用户，密码是否正确
        // 如果存在，则返回true，否则返回false
    }

    type Menu struct {
        Id int
        Name string
        Price float64
        Image string
    }

    func getMenuList() []Menu {
        // 查询数据库，获取菜品列表信息
        // 将信息封装为Menu类型的slice返回
    }

    type MenuOrder struct {
        MenuId int
        Count int
    }

    func reserve(username string, orderTime string, eatTime string, eatNumber int, menuOrder []MenuOrder) bool {
        // 生成订单编号
        // 在订单表中新增一条订单信息
        // 在菜品订单表中新增相关信息
        // 返回预约结果（成功或失败）
    }

    type OrderInfo struct {
        OrderId int
        OrderTime string
        EatTime string
        EatNumber int
        MenuList []MenuOrder
        Status int   // 1表示预约成功，2表示已就餐，3表示已取消
    }

    func getOrderList(username string) []OrderInfo {
        // 查询指定用户的订单信息
        // 将信息封装为OrderInfo类型的slice返回
    }

    func login(username string, password string) bool {
        db, err := sql.Open("Mysql", "root:password@tcp(localhost:3306)/restaurant")
        if err != nil {
            log.Fatal(err)
        }
        defer db.Close()

        rows, err := db.Query("SELECT * FROM user_info WHERE username = ? AND password = ?", username, password)
        if err != nil {
            log.Fatal(err)
        }
        defer rows.Close()

        if rows.Next() {
            return true
        } else {
            return false
        }
    }

    type Menu struct {
        Id int
        Name string
        Price float64
        Image string
    }

    func getMenuList() []Menu {
        db, err := sql.Open("mysql", "root:password@tcp(localhost:3306)/restaurant")
        if err != nil {
            log.Fatal(err)
        }
        defer db.Close()

        rows, err := db.Query("SELECT id, name, price, image FROM menu_info")
        if err != nil {
            log.Fatal(err)
        }
        defer rows.Close()

        var menuList []Menu
        for rows.Next() {
            var id int
            var name string
            var price float64
            var image string
            err := rows.Scan(&id, &name, &price, &image)
            if err != nil {
                log.Fatal(err)
            }

            menu := Menu{
                Id: id,
                Name: name,
                Price: price,
                Image: image,
            }
            menuList = append(menuList, menu)
        }
        return menuList
    }

    type MenuOrder struct {
        MenuId int
        Count int
    }

    func reserve(username string, orderTime string, eatTime string, eatNumber int, menuOrder []MenuOrder) bool {
        db, err := sql.Open("mysql", "root:password@tcp(localhost:3306)/restaurant")
        if err != nil {
            log.Fatal(err)
        }
        defer db.Close()

        tx, err := db.Begin()
        if err != nil {
            log.Fatal(err)
        }

        stmt1, err := tx.Prepare("INSERT INTO order_info(order_time, eat_time, eat_number, status) VALUES (?, ?, ?, ?)")
        if err != nil {
            tx.Rollback()
            log.Fatal(err)
        }
        defer stmt1.Close()

        res, err := stmt1.Exec(orderTime, eatTime, eatNumber, 1) // 预约成功
        if err != nil {
            tx.Rollback()
            log.Fatal(err)
        }

        orderId, err := res.LastInsertId()
        if err != nil {
            tx.Rollback()
            log.Fatal(err)
        }

        stmt2, err := tx.Prepare("INSERT INTO menu_order_info(order_id, menu_id, count) VALUES (?, ?, ?)")
        if err != nil {
            tx.Rollback()
            log.Fatal(err)
        }
        defer stmt2.Close()

        for _, menu := range menuOrder {
            _, err := stmt2.Exec(orderId, menu.MenuId, menu.Count)
            if err != nil {
                tx.Rollback()
                log.Fatal(err)
            }
        }

        err = tx.Commit()
        if err != nil {
            tx.Rollback()
            log.Fatal(err)
        }

        return true
    }

    type OrderInfo struct {
        OrderId int
        OrderTime string
        EatTime string
        EatNumber int
        MenuList []MenuOrder
        Status int   // 1表示预约成功，2表示已就餐，3表示已取消
    }

    func getOrderList(username string) []OrderInfo {
        db, err := sql.Open("mysql", "root:password@tcp(localhost:3306)/restaurant")
        if err != nil {
            log.Fatal(err)
        }
        defer db.Close()

        rows, err := db.Query("SELECT order_info.id, order_time, eat_time, eat_number, status, menu_id, count FROM order_info INNER JOIN menu_order_info ON order_info.id = menu_order_info.order_id WHERE username = ?", username)
        if err != nil {
            log.Fatal(err)
        }
        defer rows.Close()

        var orderList []OrderInfo
        for rows.Next() {
            var orderId int
            var orderTime string
            var eatTime string
            var eatNumber int
            var status int
            var menuId int
            var count int
            err := rows.Scan(&orderId, &orderTime, &eatTime, &eatNumber, &status, &menuId, &count)
            if err != nil {
                log.Fatal(err)
            }

            var order *OrderInfo
            for i, item := range orderList {
                if item.OrderId == orderId {
                    order = &orderList[i]
                    break
                }
            }

            if order == nil {
                order = &OrderInfo{
                    OrderId: orderId,
                    OrderTime: orderTime,
                    EatTime: eatTime,
                    EatNumber: eatNumber,
                    Status: status,
                    MenuList: make([]MenuOrder, 0),
                }
                orderList = append(orderList, *order)
            }

            menuOrder := MenuOrder{
                MenuId: menuId,
                Count: count,
            }
            order.MenuList = append(order.MenuList, menuOrder)
        }
        return orderList
    }