Question

我有这个HQL查询，它返回表中的所有产品。但我想只获得最新价格日期的产品，而不是旧产品。我怎么能这样做。

String select = "SELECT p FROM  ProductPricing p where p.productId.supplierId.id=:id"; // nested condition based on the FK productpricing -> product -> supplier

    Query query = hibernateSession.createQuery(select);
    query.setParameter("id", Integer.parseInt(dsRequest.getFieldValue("supplier").toString()));

    List<ProductPricing> models = query.list();

    for (int i = 0; i < models.size(); i++)
    {
        if (models.get(i).getProductId() != null)
        {
            models.get(i).getProductId().getProductCode();
            models.get(i).getProductId().getBrandName();
            models.get(i).getPurchasePrice();
            System.out.println(models.get(i).getProductId().getBrandName());
        }

    }

我的ProductPrice表格如下所示。现在这个我的HQL查询返回所有记录。但我只是想让它返回最新的价格日期，即那些productID的id 2和4

id priceDate                   purchasePrice salesPrice consumerPrice productID description 

1  2012-11-15 00:00:00         1000          1200       1500          1         qwqw        
2  2013-11-16 00:00:00         1600          1800       2100          1         new price   
3  2012-10-15 00:00:00         1600          1500       1600          2         erere   
4  2013-11-02 00:00:00         1600          1900       3400          2         new price

Answer 1

这是返回最后30个日期定价

String select = "SELECT p.salesPrice FROM  ProductPricing p where p.productId.supplierId.id=:id ORDER BY p.priceDate desc"; 
Query query = hibernateSession.createQuery(select);
query.setParameter("id", Integer.parseInt(dsRequest.getFieldValue("supplier").toString()));

List<ProductPricing> models = query.list();

在业务逻辑中过滤结果，我认为这就是你设计db的方式（一对多关系）

这是SQL：

CREATE TABLE `testspring`.`pricing`(     `id` INT NOT NULL AUTO_INCREMENT ,     `priceDate` DATETIME ,     `purchasePrice` INT ,     `salesPrice` INT ,     `consumerPrice` INT ,     `productID` INT ,     `description` VARCHAR(255) ,     PRIMARY KEY (`id`)  );

INSERT INTO `testspring`.`pricing`(`id`,`priceDate`,`purchasePrice`,`salesPrice`,`consumerPrice`,`productID`,`description`) VALUES ( NULL,'2012-11-15 00:00:00','1000','1200','1500','1','qwqw');
INSERT INTO `testspring`.`pricing`(`id`,`priceDate`,`purchasePrice`,`salesPrice`,`consumerPrice`,`productID`,`description`) VALUES ( NULL,'2013-11-16 00:00:00',1500,1600,1500,1,'new price');

INSERT INTO `testspring`.`pricing`(`id`,`priceDate`,`purchasePrice`,`salesPrice`,`consumerPrice`,`productID`,`description`) VALUES ( NULL,'2012-10-15 00:00:00','1600','1500','1600','2','qwqw');
INSERT INTO `testspring`.`pricing`(`id`,`priceDate`,`purchasePrice`,`salesPrice`,`consumerPrice`,`productID`,`description`) VALUES ( NULL,'2013-11-02 00:00:00','1600','1900','3400','2','new price');

SELECT p.salesPrice FROM  pricing p INNER JOIN pricing pp ON p.productID = pp.productID AND p.priceDate>pp.priceDate 
WHERE p.description<>pp.description

Answer 2

您可以尝试这样：

String select = "SELECT p FROM  ProductPricing p where p.productId.supplierId.id=:id and p.priceDate = NOW()"; 
Query query = hibernateSession.createQuery(select);
query.setParameter("id", Integer.parseInt(dsRequest.getFieldValue("supplier").toString()));

List<ProductPricing> models = query.list();

HQL查询有助于从mssql db返回最新日期

2 个答案: