【发布时间】：2019-04-02 17:55:46
【问题描述】：
我确切地说我是 Java 开发者一年级的法国学生。 而且我很确定我的问题标题对于我正在尝试做的事情甚至都不正确。那我希望下面的解释会更清楚！
我正在开发一个小的多模块应用程序，使用：Spring Boot、Spring security、Hibernate、Spring Data、Spring MVC 和 Thymeleaf。
这里是my repo
我目前正在研究一种处理多条件请求的方法。 我正在使用 Querydsl。
这是涉及到的域：
母实体
@Entity
@Table(name="element")
@Inheritance(strategy = InheritanceType.JOINED)
@Getter
@Setter
@NoArgsConstructor
@ToString
@EqualsAndHashCode
public abstract class Element {
//----------ATTRIBUTES----------
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
@NotNull
@Size(min=4,max=50)
private String name;
private LocalDateTime createDate;
private LocalDateTime updateDate;
@OneToMany/*(mappedBy = "element")*/
@JoinColumn(name = "element_id")
private List< Comment > comments;
//..
子实体
/**
* Bean used to define a book or a document that contains one or many climbing areas
*/
@Entity
@Table(name="atlas")
@PrimaryKeyJoinColumn(name = "element_id")
@Getter
@Setter
@NoArgsConstructor
@ToString( exclude = {"areas" , "bookingRequests" , "user"})
public class Atlas extends Element {
//----------ATTRIBUTES----------
@ManyToMany
@JoinTable(
name = "areas_in_atlases",
joinColumns = { @JoinColumn(name = "atlas_id") },
inverseJoinColumns = { @JoinColumn(name = "area_id") } )
private List< Area > areas;
private String scale;
private String country;
private String region;
private String department;
private boolean available;
@ManyToOne
@JoinColumn(name = "user_id")
private User user;
@OneToMany(mappedBy = "atlas", cascade = CascadeType.ALL)
private List<BookingRequest> bookingRequests;
//..
/**
* Bean used to define an area with one or many climbing crag
*/
@Entity
@Table(name="area")
@PrimaryKeyJoinColumn(name = "element_id")
@Getter
@Setter
@NoArgsConstructor
@ToString
@EqualsAndHashCode( callSuper = true )
public class Area extends Element {
//----------ATTRIBUTES----------
@ManyToMany(mappedBy = "areas")
private List< Atlas > atlases;
private Atlas atlas;
@OneToMany/*(mappedBy = "area", fetch = FetchType.LAZY)*/
@JoinColumn(name = "area_id")
private List< Crag > crags;
private int approachDuration;
private String locality;
@OneToMany/*(mappedBy = "area", fetch = FetchType.LAZY)*/
@JoinColumn(name = "area_id")
private List< Parking > parking;
private String rockType;
//..
我的多标准方法的第一部分正在工作（我猜不是很优雅..）：
@Override
public Page<Atlas> searchAtlasByNameAndCountryAndRegionAndDepartment( int page, int size, String name, String country, String region, String department ){
QAtlas qAtlas = QAtlas.atlas;
ArrayList< Predicate > predicates = new ArrayList<>();
List<Atlas> atlases;
if( !name.equals( "" ) ){
predicates.add( qAtlas.name.containsIgnoreCase(name) );
}
if( !country.equals( "" ) ){
predicates.add( qAtlas.country.containsIgnoreCase(country) );
}
if( !region.equals( "" ) ){
predicates.add( qAtlas.region.containsIgnoreCase(region) );
}
if( !department.equals( "" ) ){
predicates.add( qAtlas.department.containsIgnoreCase(department) );
}
BooleanBuilder booleanBuilder = new BooleanBuilder();
for ( Predicate predicate: predicates ) {
booleanBuilder.and(predicate);
}
atlases = ( List< Atlas > ) getDaoFactory().getAtlasRepository().findAll( booleanBuilder );
long total = ( long ) atlases.size( );
return new PageImpl(atlases, PageRequest.of( page, size ), total );
}
但我坚持使用仅在 Atlas 中的字段（例如 Country）在 Area 中搜索的方法。
@Override
public Page< Area > searchAreaByNameAndCountryAndRegionAndDepartment( int page, int size, String name, String country, String region, String department ){
QAtlas qAtlas = QAtlas.atlas;
QArea qArea = QArea.area;
final JPAQueryFactory queryFactory = new JPAQueryFactory(em);
List<Area> areas = queryFactory.selectFrom(qArea)
.innerJoin(qAtlas)
.where(
qArea.name.containsIgnoreCase(name),
qAtlas.country.containsIgnoreCase(country),
qAtlas.department.containsIgnoreCase(department),
qAtlas.region.containsIgnoreCase(region)
)
.fetch();
long total = ( long ) areas.size( );
return new PageImpl(areas, PageRequest.of( page, size ), total );
}
目前控制台显示：
ervlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.IllegalArgumentException: org.hibernate.hql.internal.ast.QuerySyntaxException: Invalid path: 'atlas.areas' [select area
from org.thibaut.wheretoclimb.model.entity.Area area
inner join atlas.areas as area
where lower(area.name) like ?1 escape '!' and lower(atlas.country) like ?2 escape '!' and lower(atlas.department) like ?1 escape '!' and lower(atlas.region) like ?1 escape '!']] with root cause
org.hibernate.hql.internal.ast.QuerySyntaxException: Invalid path: 'atlas.areas' [select area
from org.thibaut.wheretoclimb.model.entity.Area area
inner join atlas.areas as area
where lower(area.name) like ?1 escape '!' and lower(atlas.country) like ?2 escape '!' and lower(atlas.department) like ?1 escape '!' and lower(atlas.region) like ?1 escape '!']
有人可以帮我解决这个问题吗？
非常感谢你们抽出宝贵的时间！
【问题讨论】：
-
在运行该查询时，您从 QueryDSL 获得的结果 SQL 是什么？
-
@Makoto 我在帖子中添加了异常。问题是如果我在 pgAdmin 中测试这个查询，我会得到我想要的区域：SELECT * FROM Area INNER JOIN Atlas ON atlas.country = 'aCountry' 但正如你所看到的，我不知道如何“翻译”那个查询在 JPAQuery 中。
-
@Makato ...等等..？ :)
-
我无能为力，因为我无法设置 QueryDSL 来执行任何这些操作，但据我所知，您的问题中有足够的信息来获得答案。耐心点。 :)
-
我终于找到了解决办法（请看原帖末尾）！不幸的是，我真的不明白为什么查询与 SQL 查询不同......无论如何，它可以工作，所以......
标签： java spring-data querydsl predicate