# 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!


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://blakes-organization.gitbook.io/rainsister/springboot-2.x/database/postgresql.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.