在一个Boot项目中导入Mybatis-Plus 和MySql依赖
MyBatis-Plus:
<dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.3.1</version> </dependency>
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MySql:这里因为依赖仲裁(父依赖中指定了版本号) 所以不需要指定版本
<dependency> <groupId>com.mysql</groupId> <artifactId>mysql-connector-j</artifactId> </dependency>
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准备一个简单的表和几条数据
![准备数据](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
在resources下创建application.yml文件
在application.yml加入数据库连接信息
![配置数据库连接](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
在目录下创建包Mapper、controller、Pojo 这里只做示例所以没有建service包
![结构](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
mapper类
package com.y.Mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper; import com.y.Pojo.User; import org.apache.ibatis.annotations.Mapper; public interface UserMapper extends BaseMapper<User> { }
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实体类
package com.y.Pojo;
import com.baomidou.mybatisplus.annotation.IdType; import com.baomidou.mybatisplus.annotation.TableField; import com.baomidou.mybatisplus.annotation.TableId; import com.baomidou.mybatisplus.annotation.TableName; import lombok.Data; import org.springframework.stereotype.Component;
@Data @TableName("tb_user") public class User { @TableId(type = IdType.AUTO) private Integer id; @TableField("username") private String username; @TableField("password") private String password; }
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启动类
package com.y;
import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication @MapperScan("com.y.Mapper") public class MyApp { public static void main(String[] args) { SpringApplication.run(MyApp.class,args); } }
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控制层
@Autowired private UserMapper userMapper;
@RequestMapping(value = "/selectById/{id}",method = {RequestMethod.POST})
public User selectById(@PathVariable Integer id){ return userMapper.selectById(id); } @RequestMapping(value = "/insert",method = {RequestMethod.POST})
public String insert(User user){ int insert = userMapper.insert(user); if(insert>0){ return "插入成功"; }else { return "插入失败"; } }
@RequestMapping(value = "/queryList",method = RequestMethod.POST) public List<User> queryList(){ return userMapper.selectList(null); }
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下面用Apipost测试
- 根据主键查询
![](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
- 插入
![](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
- 查询全部
![](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
==注意:一定要在对应类上加@Mapper或者在启动类上加MapperScan==