Question

说，我有两个实体：

参数

@Entity
@Table(name = "PAR")
public class Par implements java.io.Serializable, Simple {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ID", updatable = false, nullable = false)
    private int id; // id

    @Column(name = "CD", updatable = false, nullable = false)
    private String cd; // cd 

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

    @Column(name = "VAL_TP", updatable = false, nullable = true)
    private String tp; 

    @Column(name = "DATA_TP", updatable = false, nullable = true)
    private String dataTp; 

    public Integer getId() {
        return this.id;
    }
    public void setId(Integer id) {
        this.id = id;
    }

    public String getCd() {
        return this.cd;
    }
    public void setCd(String cd) {
        this.cd = cd;
    }

    public String getTp() {
        return tp;
    }
    public void setTp(String tp) {
        this.tp = tp;
    }

    public String getDataTp() {
        return dataTp;
    }
    public void setDataTp(String dataTp) {
        this.dataTp = dataTp;
    }

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

}

了Dw

@Entity
@Table(name = "DW")
public class Dw implements java.io.Serializable, Simple {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ID", updatable = false, nullable = false)
    private int id;

    @Column(name = "S1", updatable = true)
    private String s1;

    @Column(name = "NS1", updatable = true)
    private Double n1;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name="FK_HFP", referencedColumnName="ID")
    private Par par; 

    public Dw() {
    }


    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }

    public String getS1() {
        return s1;
    }
    public void setS1(String s1) {
        this.s1 = s1;
    }

    public Double getN1() {
        return n1;
    }

    public void setN1(Double n1) {
        this.n1 = n1;
    }   

    public Par getPar() {
        return par;
    }

    public void setPar(Par par) {
        this.par = par;
    }


}

我需要找到与par.cd =“TEST1”匹配的“dw”行并获取S1字段的值。

我必须通过dw迭代来完成：

for (Dw dw: dwMng.findAll()) {
    if (dw.getPar().getCd()=="TEST1") {
     System.out.println("Found row with par.cd:"+dw.getPar().getCd()+" value of S1="+dw.getS1);
    }
}

但我认为这样做并不方便。

我怎样才能快速获得这样的排？

例如（不使用dw.getPar（））：

for (Dw dw: dwMng.findAll()) {
    if (dw.getCdOfPar("Test1")=="TEST1") {
     System.out.println("Found row with par.cd:"+dw.getPar().getCd()+" value of S1="+dw.getS1);
    }
}

或者可能存在另一种方式来完成这项工作？

我可以不经迭代而没有HQL和SQLQuery吗？

淡香水

我只需要将子字段“嵌入”父级

Answer 1

在这种情况下，你也可以写一个NamedQuery。

你可以写下面的内容

String sql = "select * from Employer employer
              join Employee employee on employee.employerid = employer.id 
              where employer.name = :name";                 

SQLQuery query = session.createSQLQuery(sql);
query.addEntity(Object.class);
query.setParameter("name", name);
List results = query.list();

Hibernate，@ ManyToOne按参数获取实体

参数

了Dw

我可以不经迭代而没有HQL和SQLQuery吗？

淡香水

1 个答案: