[英]Return data even if the foreign key is null in HQL
我有一個Product
表,該ProductCategory
表通過@ManyToOne
和@OneToMany
關系連接到ProductCategory
表。 Product
:
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "category_id")
@NotFound(action=NotFoundAction.IGNORE)
private ProductCategory productCategory;
Category
:
@OneToMany(fetch = FetchType.LAZY, mappedBy="productCategory" ,cascade = {CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REFRESH})
@JsonBackReference
@OrderBy("id desc")
private Set<Product> products = new HashSet<Product>();
我有這個存儲庫方法,可以從Product
表中檢索數據:
@Query("SELECT p from Product p where cast(p.id as string) like :x or p.name like :x or p.description like :x or p.sku like :x or p.productCategory.name like :x")
public Page<Product> search(@Param("x") String keyword, Pageable pageable);
此方法不返回類別為null的產品。 即使在productCategory
列上為空,如何檢索產品。
我通過LEFT JOIN
查詢添加(實際上) LEFT JOIN
來解決了這個問題:
"SELECT p from Product p left join p.productCategory where cast(p.id as string) like :x or p.name like :x or p.description like :x or p.sku like :x or p.productCategory.name like :x"
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