使用ms sql server查询OneToOne映射的时间超过8秒

Question

我正在使用MS SQL server和jpa存储库。

我想连接2个表并获取前20列，我在实体类中使用了注释。

@Getter
@Setter
@ToString
@Entity
@Table(name = "TVSource")
public class MyTelevisionSource {
    @Id
    private Long SourceId;

    @Column(columnDefinition = "nvarchar2 (2000)")
    private String LongName;

    @Column(columnDefinition = "nvarchar2 (2000)")
    private String DisplayName;

    @OneToOne(fetch=FetchType.LAZY)
    @JoinColumn(name = "SourceId")
    private RCMSource rcmSource;  

}


@Getter
@Setter
@ToString
@Entity
@Table(name = "Source")
public class RCMSource {

    @Id
    private Long SourceId;

    @Column(columnDefinition = "nvarchar2 (2000)")
    private String SourceName;

}


@Service
public class TelevisionSourceService {

    @Autowired
    private TelevisionSourceRepository televisionSourceRepo;

    public List<MyTelevisionSource> getTelevisionSource(){

        Pageable pageable = PageRequest.of(0, 10);
        Page<MyTelevisionSource> tvSource =  televisionSourceRepo.findAll(pageable);

        System.out.println(tvSource.getContent());

        return tvSource.getContent();
}


public interface TelevisionSourceRepository extends JpaRepository<MyTelevisionSource, Long> {

    Page<MyTelevisionSource> findAll(Pageable pageable);

}

Page<MyTelevisionSource> findAll(Pageable pageable);

原因：org.hibernate.hql.internal.ast.QuerySyntaxException：源未映射[SELECT s.sourceId,s.sourceName,t.TvSourceLongName FROM Source as s INNER JOIN TelevisionSource as t ON s.sourceId=t.sourceId]

不知道...为什么会给

Answer 1

您真的需要懒惰（OneToOne注释的fetchType.lazy)吗？因此，您有1个主要查询检索您的电视源，然后有10个查询检索RCMSources。如果设置FetchType.Eager，则它应该生成一个带有左联接的查询