Sql 我怎样才能得到;“一”;反对来自;“许多”;多人关系中的对象?请帮帮我?
这是我的java代码:三个实体,包括Sql 我怎样才能得到;“一”;反对来自;“许多”;多人关系中的对象?请帮帮我?,sql,hibernate,jpa,Sql,Hibernate,Jpa,这是我的java代码:三个实体,包括CompanyTypeRelation、CompanyType、Department public class CompanyTypeRelation implements java.io.Serializable { private static final long serialVersionUID = 4227115995926533087L; // Fields private long id; private
CompanyTypeRelation、CompanyType、Department
public class CompanyTypeRelation implements java.io.Serializable {
private static final long serialVersionUID = 4227115995926533087L;
// Fields
private long id;
private CompanyType companyType;
private Department department;
private long operator;
private String operateTime;
// the relationship
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="company_type_id", nullable=false)
public CompanyType getCompanyType() {
return this.companyType;
}
public void setCompanyType(CompanyType companyType) {
this.companyType = companyType;
}
// the relationship
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="company_id", nullable=false)
public Department getDepartment() {
return this.department;
}
public void setDepartment(Department department) {
this.department = department;
}
..............
other code:
}
这是我的查询sql:
SELECT c
FROM com.hna.dt.orm.CompanyTypeRelation c
LEFT JOIN c.companyType ct LEFT JOIN c.department cd
我可以通过上面的sql从
Department
获取Department名称吗?假设Department名称在Department表中,只需将cd.name(或任何列名)添加到选择列表中即可。这不是sql,而是HQL。这没有多大意义。你到底想要实现什么?您希望查询的输出是什么?谢谢您的回答。部门名称在部门表中;但是当我查询sql时,我可以得到关于部门和公司类型的信息,你能帮我吗?