表结构设计

添加购物车代码

@Service
public class ShoppingCartServiceImpl implements ShoppingCartService {@Autowiredprivate ShoppingCartMapper shoppingCartMapper;@Autowiredprivate DishMapper dishMapper;@Autowiredprivate SetmealMapper setmealMapper;/*** 添加购物车** @param shoppingCartDTO*/public void addShoppingCart(ShoppingCartDTO shoppingCartDTO) {ShoppingCart shoppingCart = new ShoppingCart();BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);//只能查询自己的购物车数据shoppingCart.setUserId(BaseContext.getCurrentId());//判断当前商品是否在购物车中List<ShoppingCart> shoppingCartList = shoppingCartMapper.list(shoppingCart);if (shoppingCartList != null && shoppingCartList.size() == 1) {//如果已经存在，就更新数量，数量加1shoppingCart = shoppingCartList.get(0);shoppingCart.setNumber(shoppingCart.getNumber() + 1);shoppingCartMapper.updateNumberById(shoppingCart);} else {//如果不存在，插入数据，数量就是1//判断当前添加到购物车的是菜品还是套餐Long dishId = shoppingCartDTO.getDishId();if (dishId != null) {//添加到购物车的是菜品Dish dish = dishMapper.getById(dishId);shoppingCart.setName(dish.getName());shoppingCart.setImage(dish.getImage());shoppingCart.setAmount(dish.getPrice());} else {//添加到购物车的是套餐Setmeal setmeal = setmealMapper.getById(shoppingCartDTO.getSetmealId());shoppingCart.setName(setmeal.getName());shoppingCart.setImage(setmeal.getImage());shoppingCart.setAmount(setmeal.getPrice());}shoppingCart.setNumber(1);shoppingCart.setCreateTime(LocalDateTime.now());shoppingCartMapper.insert(shoppingCart);}}