Day 73 - orm(객체와 테이블 매핑)을 이용한 프로그램 만들기

orm : Object Relational Mapping 

 

Maven Java 프로젝트 만들기

 

pom.xml

plugin 추가

	<plugins>
	    <plugin>    
	        <artifactId>maven-compiler-plugin</artifactId>
	        <configuration>
	            <source>1.8</source>
	            <target>1.8</target>
	        </configuration>
	    </plugin>
	</plugins>

dependencies 추가

		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.13</version>
			<scope>test</scope>
		</dependency>    
		<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
		<dependency>
		    <groupId>org.projectlombok</groupId>
		    <artifactId>lombok</artifactId>
		    <version>1.18.34</version>
		    <scope>provided</scope>
		</dependency>
		<!-- https://mvnrepository.com/artifact/com.h2database/h2 -->
		<dependency>
		    <groupId>com.h2database</groupId>
		    <artifactId>h2</artifactId>
		    <version>1.4.200</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-entitymanager -->
		<dependency>
		    <groupId>org.hibernate</groupId>
		    <artifactId>hibernate-entitymanager</artifactId>
		    <version>5.2.18.Final</version>
		</dependency>

java>META-INF>persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
	<persistence-unit name="day56" transaction-type="RESOURCE_LOCAL">
		<class>day56.Dept</class>
		<properties>
			<property name="javax.persistence.jdbc.driver" value="org.h2.Driver"/>
			<property name="javax.persistence.jdbc.url" value="jdbc:h2:tcp://localhost/~/test08"/>
			<property name="javax.persistence.jdbc.user" value="scott"/>
			<property name="javax.persistence.jdbc.password" value="tiger"/>
			
			<property name="hibernate.hbm2ddl.auto" value="None"/>
			<property name="org.hibernate.dialect.Dialect" value="org.hibernate.dialect.H2Dialect"/>
			<property name="hibernate.show_sql" value="true"/>
			<property name="hibernate.format_sql" value="true"/>
			<property name="hibernate.use_sql_comments" value="true"/>
    	</properties>
	</persistence-unit>
</persistence>

Dept

package day56;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.RequiredArgsConstructor;
import lombok.Setter;
import lombok.ToString;


@Entity
//@Getter
//@Setter
//@ToString
//@RequiredArgsConstructor
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class Dept {
	@Id
	@GeneratedValue(strategy = GenerationType.AUTO) // auto increment
	int deptno;
	String dname;
	String loc;
}

main.java

package day56;

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;
import javax.persistence.Query;
import javax.persistence.TypedQuery;

public class App {

	public static void main(String[] args) {
		EntityManagerFactory mf = Persistence.createEntityManagerFactory("day56");
		EntityManager em = mf.createEntityManager();
		EntityTransaction tx = em.getTransaction();
		tx.begin();
		// JPA 사용하기 
		Dept dept=Dept.builder()
					.dname("test")
					.loc("test")
					.build();
		em.persist(dept); // 입력 
		
		Dept result = em.find(Dept.class, 1);
		System.out.println(result);
		
		result.setDname("test2"); // 수정
		em.remove(result); // 지우기 
		
		// Query 사용하기
		TypedQuery<Dept> q = em.createQuery("select d from Dept d", Dept.class);
		System.out.println(q.getResultList());
		tx.commit();
		em.close();
		mf.close();
	}

}