三、SpringBoot整合数据库访问层

一、springboot整合使用JdbcTemplate

• 1.pom依赖

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-jdbcartifactId>
        dependency>
        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <version>5.1.21version>
        dependency>

• 2.application.yml新增配置

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/test
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver

• 3.建表sql

CREATE TABLE `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(32) NOT NULL COMMENT '用户名称',
  `age` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

• 4.UserService

@RestController
public class UserService {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @RequestMapping("/insertUser")
    public String insertUser(String name,Integer age){
        int update = jdbcTemplate.update("insert into users values(null,?,?);", name, age);
        return update > 0 ? "success" : "false";
    }
}

• 5.浏览器访问：http://127.0.0.1:8080/insertUser?name=你好&age=21
  

二、整合mybatis框架查询

• 1.pom依赖

    
    <dependency>
        <groupId>org.mybatis.spring.bootgroupId>
        <artifactId>mybatis-spring-boot-starterartifactId>
        <version>1.1.1version>
    dependency>

• 2.实体类UserEntity

public class UserEntity {
    private String userName;
    private Integer age;
    private Integer id;
	//GET...SET...省略
}

• 3.UserMapper接口

public interface UserMapper {
    @Select("select id as id,name as userName,age as age from users where id = #{id};")
    UserEntity selectByUserId(@Param("id") Integer id);
}

• 4.UserService

@RestController
public class UserService {
    @Autowired
    private UserMapper userMapper;
    @RequestMapping("/mybatisFindById")
    public UserEntity mybatisFindById(Integer id){
        return userMapper.selectByUserId(id);
    }
}

• 5.app启动
  • 注意：这里需要加注解@MapperScan("com.sjyl.mapper")来告诉spring接口mapper的扫包范围

@SpringBootApplication
@MapperScan("com.sjyl.mapper")
public class App {
    public static void main(String[] args) {
        SpringApplication.run(App.class);
    }
}

测试连接：http://127.0.0.1:8080/mybatisFindById?id=3

三、整合mybatis框架插入

• 1.UserMapper添加insertUser

public interface UserMapper {

    @Insert("Insert into users values (null,#{userName},#{age});")
    int insertUser(@Param("userName") String userName,@Param("age") Integer age);

    @Select("select id as id,name as userName,age as age from users where id = #{id};")
    UserEntity selectByUserId(@Param("id") Integer id);
}

• 2.UserService添加insertUserMybatis

@RestController
public class UserService {
    @Autowired
    private UserMapper userMapper;

    @RequestMapping("/mybatisFindById")
    public UserEntity mybatisFindById(Integer id){
        return userMapper.selectByUserId(id);
    }

    @RequestMapping("/insertUserMybatis")
    public String insertUserMybatis(String userName,Integer age){
        int insert = userMapper.insertUser(userName,age);
        return insert > 0 ? "success" : "false";
    }
}

测试连接：http://127.0.0.1:8080/insertUserMybatis?userName=%E5%BC%A0%E4%B8%89&age=21