NativeQueryでエンティティとスカラ値を同時にSELECTしてみる

Posted on Sunday Jan 26, 2014 at 01:06PM in Technology

NativeQueryで関連持ちエンティティをSELECTしてみるの続きです。今回はエンティティとCOUNT関数の結果を同時にSELECTしてみます。

環境

Hibernate 4.3.0.Final
WildFly8.0.0.CR1
Oracle JDK7u51
postgresql-9.3-1100.jdbc41.jar
PostgreSQL 9.2.4

何をするか

エンティティと関連の構造は前回と同じです。

今回は部署エンティティと一緒に社員数のカウントを取ってみます。

準備

配置図

図中で選択されている資源を作成または編集します。

orm.xmlにNamedNativeQuery “findDeptWithCount” とResultSetMapping “deptWithCountResult” を追加します
EntityWithScalarSelectTestを作ります
テストデータは前回のを流用します

資源

orm.xml

<?xml version="1.0" encoding="UTF-8"?>
<entity-mappings version="2.1"
    xmlns="http://xmlns.jcp.org/xml/ns/persistence/orm" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence/orm http://xmlns.jcp.org/xml/ns/persistence/orm_2_1.xsd">

    <named-native-query name="findEmployee" result-set-mapping="employeeResult">
        <query><![CDATA[
            SELECT
                emp.id,
                emp.firstName,
                emp.lastName
            FROM
                Employee AS emp
        ]]></query>
    </named-native-query>

    <named-native-query name="findEmployeeWithDept" result-set-mapping="employeeResult">
        <query><![CDATA[
            SELECT
                emp.id,
                emp.firstName,
                emp.lastName,
                emp.dept_id
            FROM
                Employee AS emp
        ]]></query>
    </named-native-query>

    <named-native-query name="findDeptWithCount" result-set-mapping="deptWithCountResult">
        <query><![CDATA[
            SELECT
                dep.id,
                dep.deptName,
                COUNT(dep.id) AS employeeCount
            FROM
                Dept AS dep,
                Employee AS emp
            WHERE
                dep.id = emp.dept_id
            GROUP BY
                dep.id
        ]]></query>
    </named-native-query>

    <sql-result-set-mapping name="employeeResult">
        <entity-result entity-class="org.arquillian.example.Employee"/>
    </sql-result-set-mapping>       

    <sql-result-set-mapping name="deptWithCountResult">
        <entity-result entity-class="org.arquillian.example.Dept"/>
        <column-result name="employeeCount"/>
    </sql-result-set-mapping>       
</entity-mappings>

EntityWithScalarSelectTest.java

この環境だとCOUNT()の結果はBigIntegerになるようですが、別の環境ではLongだったりいろいろかもしれません

package org.arquillian.example;

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.transaction.Transactional;

import org.jboss.arquillian.container.test.api.Deployment;
import org.jboss.arquillian.junit.Arquillian;
import org.jboss.arquillian.persistence.UsingDataSet;
import org.jboss.shrinkwrap.api.Archive;
import org.jboss.shrinkwrap.api.ShrinkWrap;
import org.jboss.shrinkwrap.api.asset.EmptyAsset;
import org.jboss.shrinkwrap.api.spec.WebArchive;
import org.junit.Test;
import org.junit.runner.RunWith;

@RunWith(Arquillian.class)
public class EntityWithScalarSelectTest {
    @Deployment
    public static Archive<?> createDeployment() {
        Archive<?> a = ShrinkWrap.create(WebArchive.class, "test.war")
            .addPackage(Employee.class.getPackage())
            .addAsResource("test-persistence.xml", "META-INF/persistence.xml")
            .addAsResource("META-INF/orm.xml", "META-INF/orm.xml")
            .addAsWebInfResource(EmptyAsset.INSTANCE, "beans.xml")
            .addAsWebInfResource("jbossas-ds.xml");
        return a;
    }

    @PersistenceContext
    EntityManager em;

    @Test
    @Transactional
    @UsingDataSet({"datasets/relativeSelect/dept.yml", "datasets/relativeSelect/employees.yml"})
    public void select() throws Exception {
        dumpEntityList(em.createNamedQuery("findDeptWithCount").getResultList());
    }

    protected void dumpEntityList(List<?> list){
        for(Object o : list){
            Object[] array = (Object[])o;
            Dept dept = (Dept) array[0];
            Number employees = (Number) array[1];
            System.out.printf("id=%d, deptName=%s, employees=%s, contains=%s\n",
                    dept.getId(), dept.getDeptName(), employees, em.contains(dept));
        }
    }
}

実行結果

13:05:40,545 INFO  [stdout] (pool-2-thread-9) Hibernate: SELECT dep.id, dep.deptName, COUNT(dep.id) AS employeeCount FROM Dept AS dep, Employee AS emp WHERE dep.id = emp.dept_id GROUP BY dep.id
13:05:40,548 INFO  [stdout] (pool-2-thread-9) id=-1, deptName=Sales, employees=2, contains=true
13:05:40,548 INFO  [stdout] (pool-2-thread-9) id=-2, deptName=Legal, employees=1, contains=true

この取り方でもちゃんとmanagedで返ってきているのがすごい。