如何使用jpa和Hibernate-Springboot访问查询中的子元素

Question

子级有一个名为name的参数。因此，我希望使用像“%name%”一样进行查询，这样查询就会返回一个包含查询找到的所有子项的列表。

我想做这样的事情：

@Query("select c from Parent c where lower(c.name) LIKE lower(CONCAT('%', :name, '%')) ")
    List<Parent> findByNameLIKE(@Param("name") String name);

但是使用一个父级的子级，我会使用父级的id来搜索它。我不知道我是不是解释得很好，问题是我还没能实现班与班之间的衔接。

@Entity(name = "Compania")
@Table(
    name = "compania"
)
public class Compania {
    @Id
    @SequenceGenerator(
        name = "compania_sequence",
        sequenceName = "compania_sequence",
        allocationSize = 1
    )
    @GeneratedValue(
        strategy = GenerationType.AUTO,
        generator = "compania_sequence"
    )
    @Column(
        nullable = false
    )
    private Long id;


    @Column(
        name = "name",
        nullable = false,
        unique = true
    )
    private String name;

    @Column(
        name = "bajas"
    )
    private String bajas;

    @OneToMany(
        cascade = CascadeType.ALL,
        fetch = FetchType.LAZY,
        orphanRemoval = true
    )
    private List<DefaultGroup> default_group;

@Entity
@Table
public class DefaultGroup {
    @Id
    @SequenceGenerator(
        name = "defaultGroup_sequence",
        sequenceName = "defaultGroup_sequence",
        allocationSize = 1
    )
    @GeneratedValue(
        strategy = GenerationType.SEQUENCE,
        generator = "defaultGroup_sequence"
    )
    @Column(
        nullable = false
    )
    @JsonIgnore
    private Long id;

    @Column(
        name = "idRef",
        nullable = false
    )
    private int idRef;

    @Column(
        name = "name",
        nullable = false
    )
    private String name;

    @Column(
        name = "path"
    )
    private String path;

    @ManyToOne()
    private Compania compania;

因此，我希望将defaultGroups分配给id为1的Compania,其中defaultGroup的名称类似于%x%。而我不知道如何做到这一点。谢了！

Answer 1

如果在父实体父实体中有子实体，如下所示：

@Entity
class Parent {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    
    ...

    @OneToMany(mappedBy = "parent")
    private List<Child> childs;

    ....

然后可以使用如下查询：

@Repository
public interface ParentRepository extends JpaRepository<Parent, Long> {
    List<Parent> getAllByChildsNameLike(String childName);
}

spring数据将为您生成查询。

@Repository
public interface ChildRepository extends JpaRepository<Child, Long> {
    List<Child> getAllByParentIdAndNameLike(Long parentId, String name);
}

@Query("select c from Child c where c.parent.id = ?1 and c.name like ?2")
List<Child> getChilds(Long parentId, String name);