JAVA高级面试进阶训练营视频教程

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Criteria 查询条件如果是子对象中的非主键字段会报 could not resolve property

 1 private Criteria getCriteria(Favorite favorite) {
 2         Criteria criteria = importDaoService.favoriteDao.getCriteria();
 3         if (favorite.getStatus() != null) {
 4             criteria.add(Restrictions.eq("status", favorite.getStatus()));
 5         }
 6         Product product = favorite.getProduct();
 7         if (product != null && product.getProductName() != null && !product.getProductName().isEmpty()) {
 8             // criteria.createAlias("product", "p");
 9             criteria.add(Restrictions.like("product.id", product.getProductName(), MatchMode.ANYWHERE));
10         }
11         return criteria;
12     }

以上运行正常。

然而....

 1     private Criteria getCriteria(Favorite favorite) {
 2         Criteria criteria = importDaoService.favoriteDao.getCriteria();
 3         if (favorite.getStatus() != null) {
 4             criteria.add(Restrictions.eq("status", favorite.getStatus()));
 5         }
 6         Product product = favorite.getProduct();
 7         if (product != null && product.getProductName() != null && !product.getProductName().isEmpty()) {
 8             // criteria.createAlias("product", "p");
 9             criteria.add(Restrictions.like("product.productName", product.getProductName(), MatchMode.ANYWHERE));
10         }
11         return criteria;
12     }

这么写就会报错。

最后... ，查了相关资料发现：

如果是非主键字段必须要给父对象的字段取别名。

    private Criteria getCriteria(Favorite favorite) {
        Criteria criteria = importDaoService.favoriteDao.getCriteria();
        if (favorite.getStatus() != null) {
            criteria.add(Restrictions.eq("status", favorite.getStatus()));
        }
        Product product = favorite.getProduct();
        if (product != null && product.getProductName() != null && !product.getProductName().isEmpty()) {
            criteria.createAlias("product", "p");
            criteria.add(Restrictions.like("p.productName", product.getProductName(), MatchMode.ANYWHERE));
        }
        return criteria;
    }

完美运行！