This is driving me mad. Now I'm even more stumped. It's not just ManyToMany but even OneToMany where I have FetchType set to LAZY and then I try to force the collection to be populated with "join fetch."
I thought the problem might have been that I wasn't using a Set as my data type but I changed the data type from Collection to Set and I'm still seeing the problem.
There has to be something else going on, I just don't get it. If I set the products field to eager fetched, I'll end up with just ONE ProductGroup returned and my Set of products. When I set it to lazy and try to force it being fetched, I end up with 27 ProdutGroups returned (the number of products returned.)
I suppose I could just get the List back and then use the first one in the List, but that seems sort of messed up. What am I doing wrong...
@Entity
@Table(name = "NPPProductGroup")
@NamedQueries({
@NamedQuery(name = "ProductGroup.findByProductGroupID",
query = "SELECT p FROM ProductGroup p left join fetch p.products WHERE p.productGroupID = :productGroupID")
})
public class ProductGroup implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@Column(name = "productGroupID", nullable = false)
private Integer productGroupID;
//columns and set/gets removed
@OneToMany(cascade = CascadeType.ALL, mappedBy = "productGroup", fetch=FetchType.LAZY)
private Set<Product> products;
}
@Entity
@Table(name = "NPPProduct")
public class Product implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@Column(name = "productID", nullable = false)
private Integer productID;
//cols get sets removed
@JoinColumn(name = "productGroupID", referencedColumnName = "productGroupID")
@ManyToOne(fetch=FetchType.LAZY)
private ProductGroup productGroup;
}
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