50.整合MyBatisPlus

提要

这里已经将Springboot环境创建好 这里只是整合MyBatis过程

引入Maven依赖

添加MyBatisPlus启动依赖,添加mysql-connector-java依赖

1.  
   <!-- mybatis-plus -->
2.  
   <dependency>
3.  
   <groupId>com.baomidou</groupId>
4.  
   <artifactId>mybatis-plus-boot-starter</artifactId>
5.  
   <version>3.3.1</version>
6.  
   </dependency>
7.  
   <!-- mybatis-plus代码生成器 -->
8.  
   <dependency>
9.  
   <groupId>com.baomidou</groupId>
10.  
    <artifactId>mybatis-plus-generator</artifactId>
11.  
    <version>3.3.1.tmp</version>
12.  
    </dependency>
13.  
    <!-- mysql连接 -->
14.  
    <dependency>
15.  
    <groupId>mysql</groupId>
16.  
    <artifactId>mysql-connector-java</artifactId>
17.  
    <scope>runtime</scope>
18.  
    </dependency>

添加application.yml配置

mybatis-plus配置项

1.  
   mybatis-plus:
2.  
   # xml文件路径
3.  
   mapper-locations: classpath:mapper/*.xml
4.  
   # 实体类路径
5.  
   type-aliases-package: com.数据库表对应的实体类的路径
6.  
   configuration:
7.  
   # 驼峰转换
8.  
   map-underscore-to-camel-case: true
9.  
   # 是否开启缓存
10.  
    cache-enabled: false
11.  
    # 打印sql
12.  
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
13.  
    # 全局配置
14.  
    global-config:
15.  
    # 数据库字段驼峰下划线转换
16.  
    db-column-underline: true
17.  
    # id自增类型(数据库id自增)
18.  
    id-type: 0

mysql配置项

1.  
   spring:
2.  
   datasource:
3.  
   driver-class-name: com.mysql.cj.jdbc.Driver
4.  
   username: root
5.  
   password: stone
6.  
   url: jdbc:mysql://ip:3306/库名?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&useSSL=false

添加数据库对应实体类

1.  
   @Data
2.  
   @TableName("class_table")
3.  
   public class ClassPojo {
4.  
    
5.  
   @TableId(value = "id", type = IdType.AUTO)
6.  
   private Long id;
7.  
    
8.  
   @TableField(value = "class_name")
9.  
   private String className;
10.  
     
11.  
    }

添加Mapper文件

1.  
   @Mapper
2.  
   public interface ClassMapper extends BaseMapper<ClassPojo> {
3.  
    
4.  
   }

添加Service接口

1.  
   public interface ClassVoService extends IService<ClassPojo> {
2.  
   String getClassName(Long id);//自定义方法
3.  
   }

 

 

添加Service实现类

1.  
   @Component
2.  
   public class ClassVoServiceImpl extends ServiceImpl<ClassMapper, ClassPojo> implements ClassVoService {
3.  
   public String getClassName(Long id){
4.  
   ClassPojo byId = getById (id);
5.  
   return byId.getClassName ();
6.  
    
7.  
   }
8.  
   }

添加Controller

1.  
   @RestController
2.  
   @RequestMapping("/demo")
3.  
   public class ExcelController {
4.  
   @GetMapping("/getbyid")
5.  
   public String getbyid(){
6.  
   return classVoService.getClassName (1l);
7.  
   }
8.  
   }

补充对应表结构

1.  
   CREATE TABLE `class_table` (
2.  
   `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '课程id不能为空主键',
3.  
   `class_name` varchar(255) NOT NULL COMMENT '课程名称',
4.  
   PRIMARY KEY (`id`)
5.  
   ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4;
6.  
   SQL 复制 全屏

表数据如下

id	class_name
1	语文
2	数学