Warning: file_get_contents(/data/phpspider/zhask/data//catemap/9/java/314.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181
Java 显示JSP上聚合函数的值_Java_Sql_Hibernate_Jsp_Jpa - Fatal编程技术网

Java 显示JSP上聚合函数的值

Java 显示JSP上聚合函数的值,java,sql,hibernate,jsp,jpa,Java,Sql,Hibernate,Jsp,Jpa,我正在使用Hibernate和JPA。我有实体类公司 CompanyRate.java @Entity public class CompanyRate { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private int idRate; @Column(nullable = false) private int atmosphere; @Column(nullable = t

我正在使用Hibernate和JPA。我有实体类公司

CompanyRate.java

@Entity
public class CompanyRate {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int idRate;
    @Column(nullable = false)
    private int atmosphere;
    @Column(nullable = true)
    private int salary;
    @Column(nullable = false)
    private int opportunityToDevelop;
    @Column(nullable = false)
    private int socialPackage;
    @ManyToOne(targetEntity = User.class)
    private User user;
    @ManyToOne(targetEntity = Company.class)
    Company company;
}
我想显示气氛、工资、发展机会、社会包的平均值,其中company.idcompany=?在JSP上


Ofc我可以在执行的查询上使用getResultList(),并在JSP上使用。但是我想把每个结果分配给一个变量。最好的方法是什么?

您所问的问题相当于以下SQL:

SELECT c.id,
       AVG(t.atmosphere), 
       AVG(t.salary), 
       AVG(t.opportunityToDevelop), 
       AVG(t.socialPackage)
  FROM table t, company c
 WHERE t.companyid = c.id
   AND c.id IN (:companyIds)
 GROUP BY c.id;
将上述内容转换为HQL/JPQL或利用Hibernate或JPA标准API应该是一个简单的练习


只需确保在构建的
查询上调用
setParameter(“companyId”,ListofCompanyId)
,然后根据您使用的API调用
getResultList()
list()

我可以对每个变量执行单个查询,但有一种方法可以只使用一个查询?