JPA非主键多对一关联

 

SQL:

 

 

select * from A

inner join B where A.sn = B.cp_cn

 

 

 

 

一对多： A

 

 

private List<B> cpGbs;

@OneToMany(mappedBy = "a", fetch = FetchType.LAZY)
	public List<B> getCpGbs() {
        return cpGbs;
    }

    public void setCpGbs(List<B> cpGbs) {
        this.cpGbs = cpGbs;
    }

 

 

多对一：B

 

 

private A a;

@ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "CP_SN", referencedColumnName="sn",  insertable = false, updatable = false)
    public A getA() {
        return a;
    }

 name = "CP_SN" -- 本表中的字段

 referencedColumnName="sn" -- 关联表的字段