SpringBoot數據庫連接，兩種方式，JPA和JDBC，當然還有其他方式例如Mybatis，JdbcTemplate等

一 SpringBoot JPA

1.pom配置jpa/mysql依賴

<!-- JPA數據庫依賴-->
<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<!-- Mysql連接器-->
<dependency>
 <groupId>mysql</groupId>
 <artifactId>mysql-connector-java</artifactId>
 <version>6.0.6</version>
</dependency>

2.properties.yml配置信息

#通用數據源配置
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?charset=utf8mb4&useSSL=false
spring.datasource.username=root
spring.datasource.password=root
# Hikari 數據源專用配置
spring.datasource.hikari.maximum-pool-size=20
spring.datasource.hikari.minimum-idle=5
# JPA 相關配置
spring.jpa.database-platform=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=create

3.創建POJO-UserDO

package com.lly.bean;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "springjpa_user")
public class User {
 @Id
 Integer id;
 @Column(length = 255)
 String name;
 @Column(length = 25)
 String email;
 public Integer getId() {
 return id;
 }
 public void setId(Integer id) {
 this.id = id;
 }
 public String getName() {
 return name;
 }
 public void setName(String name) {
 this.name = name;
 }
 public String getEmail() {
 return email;
 }
 public void setEmail(String email) {
 this.email = email;
 }
}

4.創建Dao

package com.lly.repository;
import com.lly.bean.User;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
@Repository
public interface UserDao extends JpaRepository<User,Long> {
}

5.創建單元測試進行運行測試

package com.lly;
import com.lly.bean.User;
import com.lly.repository.UserDao;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
@RunWith(SpringRunner.class)
@SpringBootTest
public class ApplicationTest {
 @Autowired
 private UserDao userDao;
 @Test
 public void userDaoJpa(){
 User user = new User();
 user.setId(1);
 user.setName("hello?");
 user.setEmail("[email protected]");
 userDao.save(user);
 }
}

6.查看數據庫

已經自動創建好表和插入的數據

總結：

本質是使用Hibernate進行數據庫操作

參考：

1.https://www.javatpoint.com/spring-boot-jpa

2.https://www.jianshu.com/p/c14640b63653

二 SpringBoot JDBC

1.創建數據庫表

create table user(
id int UNSIGNED primary key not null auto_increment, 
name varchar(100), 
email varchar(100)
); 

2.項目properties配置

#通用數據源配置
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root
# Hikari 數據源專用配置
spring.datasource.hikari.maximum-pool-size=20
spring.datasource.hikari.minimum-idle=5
# JPA 相關配置
spring.jpa.database-platform=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=create

3創建控制器Controller

package com.lly.controller;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class SpringBootJdbcController {
 @Autowired
 JdbcTemplate jdbcTemplate;
 @RequestMapping(value = "insert")
 public String insertUser() {
 jdbcTemplate.execute("insert into user(name,email)values('Liya','[email protected]')");//執行sql
 return "InsertUser Successful";
 }
}

4.運行Application

參考：https://www.javatpoint.com/spring-boot-jdbc