Question

I have a question about Hibernate ManyToOne association.

I have a Product entity mapped like this:

public class Product {
@Id
@DocumentId
@Column(name = "PRODUCT_ID", columnDefinition = "integer")
@Index(name = "PRODUCT_ID_IDX")
private Long id;

@Column(name = "SALE_PRICE")
@Index(name = "PRODUCT_PRICE_IDX")
private Double salePrice;
...
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "CATEGORY_ID", nullable = true)
@Index(name = "PRODUCT_ID_CATEGORY_IDX")
private ProductCategory category;
}

So how can you see we have relationship with ProductCategory table. And FK we store in Product table.
When I create query which select Product by specific category and price I have next SQL:
select
this_.PRODUCT_ID as PRODUCT1_9_1_,
this_.BUY_URL as BUY2_9_1_,
this_.CATEGORY_ID as CATEGORY15_9_1_,
this_.CURRENCY as CURRENCY9_1_,
this_.IMAGE_URL as IMAGE4_9_1_,
this_.INSTOCK as INSTOCK9_1_,
this_.LONG_DESCRIPTION as LONG6_9_1_,
this_.NAME as NAME9_1_,
this_.RATING as RATING9_1_,
this_.RETAIL_PRICE as RETAIL9_9_1_,
this_.SALE_PRICE as SALE10_9_1_,
this_.SHIPPING as SHIPPING9_1_,
this_.SHORT_DESCRIPTION as SHORT12_9_1_,
this_.UPC as UPC9_1_,
this_.VIEWS as VIEWS9_1_,
cat1_.CATEGORY_ID as CATEGORY1_10_0_,
cat1_.NAME as NAME10_0_,
cat1_.RATING as RATING10_0_,
cat1_.VIEWS as VIEWS10_0_,
cat1_.VISIBLE as VISIBLE10_0_
from
PRODUCT this_
inner join
PRODUCT_CATEGORY cat1_
on this_.CATEGORY_ID=cat1_.CATEGORY_ID
where
(
this_.SALE_PRICE between ? and ?
and cat1_.CATEGORY_ID in (
?
)
)
order by
this_.NAME asc limit ? offset ?

My question is next: How do I can avoid inner join of two tables: Product and ProductCategory?

My Criteria DAO code:
criteria.createAlias("category", "cat");
criteria.add(Restrictions.conjunction()
.add(Restrictions.between("salePrice", priceLow, priceHigh))
.add(Restrictions.in("cat.id", categoryIds)));

Thanks.

Answer 1

The line

criteria.createAlias("category", "cat");

precisely means: create an inner join with the Category entity.

Just use

criteria.add(
    Restrictions.conjunction()
        .add(Restrictions.between("salePrice", priceLow, priceHigh))
        .add(Restrictions.in("category.id", categoryIds)));