I have Certificate class that contains list of Tag classes (many to many) and I have to find Certificates that contain certain Tag (by tag name) I'm using JPA Criteria API but cannot do this..
@Entity @Table(name = "gift_certificate") public class Certificate { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private String name; private String description; private BigDecimal price; private Integer duration; @Column(name = "create_date") private LocalDateTime createDate; @Column(name = "last_update_date") private LocalDateTime lastUpdateDate; @ManyToMany @JoinTable(name = "gift_certificate_tag", joinColumns = @JoinColumn(name = "tag_id"), inverseJoinColumns = @JoinColumn(name = "gift_certificate_id") ) private List<Tag> tags; getters and setters and other code... .....
@Entity @Table(name = "tag") public class Tag { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private String name; getters and setters and other code... I tried to do it like this, but I get exception IllegalStateException: Illegal attempt to dereference path source [null.tags] of basic type
CriteriaBuilder cb = entityManager.getCriteriaBuilder(); CriteriaQuery<Certificate> query = cb.createQuery(Certificate.class); Root<Certificate> certificates = query.from(Certificate.class); certificates.fetch("tags", JoinType.LEFT); query.select(certificates).distinct(true); query.where(cb.like(certificates.get("tags").get("name"), params.getTag())); return entityManager.createQuery(query).getResultList(); 