在Hibernate中连接不同类型的列

Question

I have 2 tables. Table1 has a column called 'id' which is a number. Table2 has a column called entity_id which is varchar . Table1 has one to Many relation with Table2.

Here is my Hibernate mapping for Table1

@Entity
@Table(name="Table1")
public class Table1 implements Serializable {
    private long id;
    private List<Table2> notes;
    @Id
    @Column(name="ID")
    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id= id;
    }

    @OneToMany(fetch=FetchType.EAGER,targetEntity=Table2.class)
    @Fetch(FetchMode.JOIN)
    @JoinColumn(name="ENTITY_ID",referencedColumnName="ID")
    public List<Table2> getNotes() {
        return storeNotes;
    }
    public void setNotes(List<Table2> notes) {
        this.notes = notes;
    }
}

When I create a ctiteria with Table1 and try to list the data, I am getting Invalid number error because the type mismatch in the join column. can you please let me know how can I ast id to varchar?

Answer 1

为什么要在类型不匹配的地方选择那种设计？这是一种最佳实践，除非并且直到在这种例外情况下有确凿的用例之前，否则POJO和表中的数据类型必须一致。