建立資料庫：

use  vuesite;
CREATE TABLE city
(
    id      INT PRIMARY KEY auto_increment,
    name    VARCHAR(255),
    state   VARCHAR(255),
    country VARCHAR(255)
);

建立實體類：

package com.xbhog.pojo;

import lombok.Data;

@Data
public class City {
    private Long id;
    private String name;
    
 
private String state;
    private String country;
}

建立Mapper:

建立CityMapper並採用註解的方式實現sql對映的問題：

package com.xbhog.Mapper;

import com.xbhog.pojo.City;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

@Mapper
public interface CityMapper {
    @Select("select * from user where id = #{id}")
    
 
public City getCityId(Long id);
}

建立Service:

package com.xbhog.service;

import com.xbhog.Mapper.CityMapper;
import com.xbhog.pojo.City;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class CityService {
    @Autowired
    CityMapper cityMapper;

    
 
public City getCityId(Long id){
        return cityMapper.getCityId(id);
    }
}

使用Service註解宣告，並將該類加入到容器中，方便後面呼叫，在service層呼叫Mapper層的方法。

建立Controller:

import com.xbhog.pojo.City;
import com.xbhog.service.CityService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.annotation.Resource;

@Controller
public class Mycontro {
    @Autowired
    CityService cityService;


    @ResponseBody
    @GetMapping("/city")
    public City getCity(@RequestParam("id") Long id){
        return cityService.getCityId(id);
    }
}

增加資料庫資訊：

測試：

mybatis混合版：

我們在CItyMapper中新增一個方法：

package com.xbhog.Mapper;

import com.xbhog.pojo.City;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import java.util.List;

@Mapper
public interface CityMapper {
    @Select("select * from city where id = #{id}")
    public City getCityId(Long id);

    public void addCity(City city);
}

這個方法我們採用配置檔案來繫結。

建立CityMapper.xml檔案：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xbhog.Mapper.CityMapper">
    
    <insert id="addCity" parameterType="com.xbhog.pojo.City">
        insert into city(`name`,`state`,`country`) values (#{name},#{state},#{country});
    </insert>
</mapper>

其中名稱空間與CityMapper要對應，進行插入操作。

在Service層增加方法：

package com.xbhog.service;

import com.xbhog.Mapper.CityMapper;
import com.xbhog.pojo.City;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class CityService {
    @Autowired
    CityMapper cityMapper;

    public void addCity(City city){
        cityMapper.addCity(city);
    }
}

https://www.cnblogs.com/xbhog/p/15201414.html