- I have five tables: Company, Product/Service, Address, Country and City.
- A Company can have n products with category, 1 address with 1 country and 1 city inside the address entity.
- A user has chosen "England - Leeds".
- I know now that I have to select every companies from db where city is Leeds and populate product/service-list with those companies' products or services. After that user can select for instance dentist from the third list.
- After that I know Enlgand - Leeds - Dentist and I have to populate the last list with compenies (dentists in Leeds)
public class Company implements java.io.Serializable {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Short companyId;
@OneToOne(cascade=CascadeType.PERSIST)
private Address address;
private String companyName;
@OneToMany(fetch = FetchType.LAZY, mappedBy = "company",cascade=CascadeType.PERSIST)
private Set<Product> products = new HashSet<Product>(0);
public class Product implements java.io.Serializable {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "productId", unique = true, nullable = false)
private Integer productId;
private Short branchId;
private String productName;
private String sku;
private String category; ------> I am using this field in company search (dentists, garages etc.)
How can I query only those companies which have products with category dentist?
CriteriaBuilder criteriaBuilder = em.getCriteriaBuilder();
CriteriaQuery<Company> criteria = criteriaBuilder.createQuery( Company.class );
Root<Company> companyRoot = criteria.from( Company.class );
//criteria.select(companyRoot);
TypedQuery<Company> q = em.createQuery(criteria);
List<Company> results = q.getResultList();
Now I've got every company, how can I select only the companies with the correct category? I think I will need JOIN but how I don't know how to use it.
