抱歉,SQL 查询很困惑。
我有这个数据结构
@Entity
public class Stock {
//Composite PK?
@Id
@NotNull
private String id;
@NotNull
private String product_id;
@NotNull
private Integer quantity;
@NotNull
private LocalDateTime timestamp;
还有
public class ProductSold {
private String productId;
private Integer itemsSold;
两个类都有适当的构造函数。
我有相应的库存存储库
public interface StockRepository extends JpaRepository<Stock, String> {
我想做的是一个棘手的 SQL 查询(注释更容易可视化查询),它应该返回 ProductSold 列表而不是 Stock
/*
SELECT (t1.quantity - t2.quantity) as itemsSold, t1.product_id as pd
FROM stock t1 CROSS JOIN
stock t2
WHERE MONTH(t1.timestamp) = 8 AND DAY(t1.timestamp) = 26
AND MONTH(t2.timestamp) = 8 AND DAY(t2.timestamp) = 27
AND t1.product_id = t2.product_id
ORDER BY itemsSold DESC
LIMIT 3;
*/
//Not working, not too sure why, says it can't find column quantity. In my view it should be working since it's a valid SQL Query.
@Query(value = "SELECT new com.stock.stock.model.ProductSold(t1.product_id as productId, (t1.quantity - t2.quantity) as itemsSold )" +
" FROM Stock t1 CROSS JOIN Stock t2" +
" WHERE MONTH(t1.timestamp) = ?1 AND DAY(t1.timestamp) = ?2" +
" AND MONTH(t2.timestamp) = ?3 AND DAY(t2.timestamp) = ?4" +
" AND t1.product_id = t2.product_id" +
" ORDER BY itemsSold DESC" +
" LIMIT 3", nativeQuery = true)
List<ProductSold> findItemsSoldByTimestamp(int month1, int day1, int month2, int day2);
但是我得到了这个:
org.h2.jdbc.JdbcSQLSyntaxErrorException:SQL 语句中存在语法错误“SELECT NEW COM.[*]STOCK.STOCK.MODEL.PRODUCTSOLD(T1.PRODUCT_ID AS ProductID, (T1.QUANTITY - T2.QUANTITY) AS ITEMSSOLD ) ....
知道出了什么问题吗?我尝试不在 SQL 表达式中进行构造,但出现 ConverterNotFoundException
最佳答案
您正在使用仅在 JPQL 中可用的构造函数表达式,但您还将查询标记为 native ,即 SQL,但它不是。
关于java - 无法在 JPA 查询中进行投影,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/58380167/