> For the complete documentation index, see [llms.txt](https://blakes-organization.gitbook.io/rainsister/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://blakes-organization.gitbook.io/rainsister/springboot-2.x/database/postgresql.md).

# PostgreSQL

다운로드 <https://www.enterprisedb.com/downloads/postgres-postgresql-downloads>

<figure><img src="/files/mKD3xv5z17hNTFLosQHj" alt=""><figcaption></figcaption></figure>

pom.xml 작성

```xml
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <scope>runtime</scope>
</dependency>
```

application.properties

```properties
spring.datasource.url=jdbc:postgresql://localhost:5432/test
spring.datasource.username=postgres
spring.datasource.password=123456
spring.datasource.driver-class-name=org.postgresql.Driver

spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect
spring.jpa.properties.hibernate.hbm2ddl.auto=create
```

application.yml

```yaml
spring:
    datasource:
        driver-class-name: org.postgresql.Driver
        password: 123456
        url: jdbc:postgresql://localhost:5432/test
        username: postgres
    jpa:
        properties:
            hibernate:
                dialect: org.hibernate.dialect.PostgreSQLDialect
                hbm2ddl:
                    auto: create
```

UserInfo 객체 생성 (user\_info 테이블과 매핑)

```java
@Entity
@Data
@NoArgsConstructor
public class UserInfo {

    @Id
    @GeneratedValue
    private Long id;

    private String name;
    private Integer age;

    public UserInfo(String name, Integer age) {
        this.name = name;
        this.age = age;
    }
}
```

interface 작성

```java
public interface UserInfoRepository extends JpaRepository<UserInfo, Long> {

    UserInfo findByName(String name);

    UserInfo findByNameAndAge(String name, Integer age);

    @Query("from UserInfo u where u.name=:name")
    UserInfo findUser(@Param("name") String name);

}
```

```java
@Slf4j
@SpringBootTest
public class ApplicationTests {

    @Autowired
    private UserInfoRepository userRepository;

    @Test
    public void test() throws Exception {

        userRepository.save(new UserInfo("AAA", 10));
        userRepository.save(new UserInfo("BBB", 20));
        userRepository.save(new UserInfo("CCC", 30));
        userRepository.save(new UserInfo("DDD", 40));
        userRepository.save(new UserInfo("EEE", 50));
        userRepository.save(new UserInfo("FFF", 60));
        userRepository.save(new UserInfo("GGG", 70));
        userRepository.save(new UserInfo("HHH", 80));
        userRepository.save(new UserInfo("III", 90));
        userRepository.save(new UserInfo("JJJ", 100));

 
        Assertions.assertEquals(10, userRepository.findAll().size());
        Assertions.assertEquals(60, userRepository.findByName("FFF").getAge().longValue());
        Assertions.assertEquals(60, userRepository.findUser("FFF").getAge().longValue());
        Assertions.assertEquals("FFF", userRepository.findByNameAndAge("FFF", 60).getName());
        userRepository.delete(userRepository.findByName("AAA"));
        Assertions.assertEquals(9, userRepository.findAll().size());

    }

}
```

결과

<figure><img src="/files/IcNExXosRlEB65jHPDki" alt=""><figcaption></figcaption></figure>

pgadmin

<figure><img src="/files/fGHCjxAVynygL3sU9KZ3" alt=""><figcaption></figcaption></figure>

다 만들고 생각해보니 mysql 설정할때랑 별로 다른게 없어보인다. pom 수정 , application.yml 파일 수정 하는 부분만 다를뿐. 이것이 바로 JPA 매력이다. 추상화로 되어 있어 db를 어떤 제품으로 변경하든지 java code 는 변경되는 부분으 매우 적거나 없다.

끝!