我尝试使用jpa查询和投影来检索数据的特定部分。以下是查询：

@Repository
public interface CompanyRepository extends CrudRepository<Company, Integer> {
    @Query("select co.companyID as companyid, co.companyName as companyname, co.companyAbbr as companyabbr, co.flags as flags from Company co order by companyName asc")
    List<CompanyWithFlags> getAllCompaniesWithFlags();
}

这是投影图：

public interface CompanyWithFlags {
    Integer getCompanyid();
    String getCompanyname();
    String getCompanyabbr();
    List<CompanyFlag> getFlags();
}

以下是公司实体：

@Entity
@Table(name="companies.companies")
public class Company implements Serializable {
    private static final long serialVersionUID = 1L;

    private int companyID;
    private String companyName;
    private String companyAbbr;
    ...
    private List<CompanyFlag> flags = new ArrayList<>();

    public Company() {}

    @Id
    @Column(name="pk_companyid")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @JsonView(View.AllCompaniesView.class)
    public int getCompanyID() {
        return companyID;
    }

    public void setCompanyID(int companyID) {
        this.companyID = companyID;
    }

    @Column(name="companyname", columnDefinition="VARCHAR(72)")
    @JsonView(View.AllCompaniesView.class)
    public String getCompanyName() {
        return companyName;
    }

    public void setCompanyName(String companyName) {
        this.companyName = companyName;
    }

    @Column(name="companyabbr", columnDefinition="VARCHAR(8)")
    @JsonView(View.AllCompaniesView.class)
    public String getCompanyAbbr() {
        return companyAbbr;
    }

    public void setCompanyAbbr(String companyAbbr) {
        this.companyAbbr = companyAbbr;
    }

    ...

    @ManyToMany(fetch=FetchType.LAZY)
    @JoinTable(name="companies.co_flags",
               joinColumns = @JoinColumn(name="fk_companyid", referencedColumnName="pk_companyid"),
               inverseJoinColumns = @JoinColumn(name="fk_flagid", referencedColumnName="pk_flagid"))
    @JsonView(View.AllCompaniesView.class)
    public List<CompanyFlag> getFlags() {
        return flags;
    }

    public void setFlags(List<CompanyFlag> flags) {
        this.flags = flags;
    }
}

如果我离开 CompanyFlag 通过查询和投影，一切正常。如果我不编写查询，而是使用：

List<CompanyWithFlags> findAllByOrderByCompanyNameAsc();

然后我得到了所需的数据，但是也生成了一个很长的其他（不必要的）查询列表。
实际上，hibernate（5.2.14）生成以下查询：

select 
  company0_.pk_companyid as col_0_0_, 
  company0_.companyname as col_1_0_, 
  company0_.companyabbr as col_2_0_, 
  . as col_3_0_, 
  companyfla2_.pk_flagid as pk_flagi1_9_, 
  companyfla2_.fk_categoryid as fk_categ3_9_, 
  companyfla2_.flagname as flagname2_9_ 
from companies.companies company0_ 
inner join companies.co_flags flags1_ on company0_.pk_companyid=flags1_.fk_companyid 
inner join companies.config_flags companyfla2_ on flags1_.fk_flagid=companyfla2_.pk_flagid 
order by companyName asc

显然，问题是 . as col_3_0_ ，但我不知道为什么会产生这种情况，也不知道如何消除它。有人能解释一下hibernate为什么要添加它，以及我可以在存储库中做些什么来高效地获得所需的数据吗？谢谢！