SpringBoot3中数据库集成实践详解

<!-- MySql数据库 -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>${mysql.version}</version>
</dependency>
<!-- Druid组件 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-3-starter</artifactId>
    <version>${druid-spring-boot.version}</version>
</dependency>
<!-- JDBC依赖 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
    <version>${spring-boot.version}</version>
</dependency>
<!-- MybatisPlus组件 -->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>${mybatis-plus.version}</version>
</dependency>

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    druid:
      # 数据库
      url: jdbc:mysql://localhost:3306/boot-jdbc
      username: root
      password: 123456
      driver-class-name: com.mysql.cj.jdbc.Driver
      # 连接池-初始化大小
      initial-size: 10
      # 连接池-最大连接数
      max-active: 100
      # 最大等待时间
      max-wait: 60000
      # 连接池-最小空闲数
      min-idle: 10
      # 检测空闲连接
      test-while-idle: true
      # 最小空闲时间
      min-evictable-idle-time-millis: 300000

@Configuration
public class DruidConfig {
    @Bean("dataSource")
    @ConfigurationProperties(prefix = "spring.datasource.druid")
    public DruidDataSource dataSource() {
        return new DruidDataSource();
    }
    @Bean("jdbcTemplate")
    public JdbcTemplate jdbcTemplate() {
        return new JdbcTemplate(dataSource());
    }
}

CREATE TABLE `tb_user` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  `user_name` varchar(30) NOT NULL COMMENT '用户名称',
  `email` varchar(50) DEFAULT NULL COMMENT '邮件',
  `phone` varchar(20) NOT NULL COMMENT '手机号',
  `create_time` datetime DEFAULT NULL COMMENT '创建时间',
  `update_time` datetime DEFAULT NULL COMMENT '更新时间',
  `state` int(1) DEFAULT '1' COMMENT '状态：1启用，2删除',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户基础信息';
CREATE TABLE `tb_user_extd` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  `user_id` int(11) NOT NULL COMMENT '用户ID',
  `city_name` varchar(50) DEFAULT NULL COMMENT '城市名称',
  `school` varchar(200) DEFAULT NULL COMMENT '学校名称',
  PRIMARY KEY (`id`),
  KEY `user_id_index` (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户扩展信息';

@Service
public class JdbcService {
    private static final Logger logger = LoggerFactory.getLogger(JdbcService.class);
    @Resource
    private JdbcTemplate jdbcTemplate ;
    /**
     * 添加数据
     */
    public int addData (User user){
        return jdbcTemplate.update(
                "INSERT INTO `tb_user` (`user_name`, `email`, `phone`, `create_time`, `update_time`) VALUES (?, ?, ?, ?, ?)",
                user.getUserName(),user.getEmail(),user.getPhone(),user.getCreateTime(),user.getUpdateTime());
    }
    /**
     * 查询全部
     */
    public List<User> queryAll (){
        return jdbcTemplate.query("SELECT * FROM tb_user WHERE state=1",new BeanPropertyRowMapper<>(User.class));
    }
    /**
     * 修改字段
     */
    public int updateName (Integer id,String name){
        return jdbcTemplate.update("UPDATE `tb_user` SET `user_name` = ? WHERE `id` = ?",name,id);
    }
    /**
     * 主键删除
     */
    public int deleteId (Integer id){
        return jdbcTemplate.update("DELETE FROM `tb_user` WHERE `id` = ?",id);
    }
}

@Configuration
@MapperScan("com.boot.jdbc.mapper")
public class MybatisConfig {
    /**
     * 分页
     */
    @Bean
    public MybatisPlusInterceptor paginationInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

public interface UserMapper extends BaseMapper<User> {
    /**
     * 自定义分页
     */
    IPage<UserModel> queryUserPage(@Param("page") IPage<User> page);
}

<mapper namespace="com.boot.jdbc.mapper.UserMapper">
    <select id="queryUserPage" resultType="com.boot.jdbc.entity.UserModel">
        SELECT
            tb1.id userId,
            tb1.user_name userName,
            tb1.email,
            tb1.phone,
            tb1.create_time createTime,
            tb1.update_time updateTime,
            tb1.state,
            tb2.school,
            tb2.city_name cityName
        FROM tb_user tb1
        LEFT JOIN tb_user_extd tb2 ON tb1.id = tb2.user_id
        WHERE tb1.state='1'
        ORDER BY tb1.id DESC
    </select>
</mapper>

public class UserMapperTest {
    @Resource
    private UserMapper userMapper ;
    @Test
    public void testInsert (){
        List<User> userBatch = Arrays.asList(
                new User(null,"Zhang三","Zhang@qq.com","18623459687",new Date(),new Date(),1));
        userBatch.forEach(userMapper::insert);
    }
    @Test
    public void testUpdate (){
        User user = userMapper.selectById(1);
        user.setState(2);
        userMapper.updateById(user);
    }
    @Test
    public void testDelete (){
        userMapper.deleteById(7);
    }
    @Test
    public void testQuery (){
        List<User> userColumnsList = new LambdaQueryChainWrapper<>(userMapper)
                .select(User::getUserName,User::getPhone,User::getEmail)
                .like(User::getPhone,"189").orderByDesc(User::getId).last("limit 2").list();
        userColumnsList.forEach(System.out::println);
    }
    @Test
    public void testPage (){
        // 1、默认分页查询
        IPage<User> userPage = new Page<>(2,2) ;
        IPage<User> userPageList = userMapper.selectPage(userPage,new QueryWrapper<>());
        userPageList.getRecords().forEach(System.out::println);
        // 2、自定义查询分页
        IPage<UserModel> userModelPage = userMapper.queryUserPage(userPage);
        userModelPage.getRecords().forEach(System.out::println);
    }
}