SpringBoot3集成Mybatis

Mybatis

Mybatis是一款优秀的持久层框架，支持自定义SQL，Mybatis可以通过简单的XML或注解来配置和映射原始类型、接口和Java对象为数据库中的记录

SpringBoot配置Mybatis

前提pom.xml中已经导入mybatis依赖

<dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>3.0.0</version>
</dependency>

#配置Mybatis实体和xml映射
mybatis:
  #映射XML
  mapper-locations: classpath:mapper/*.xml
  configuration:
    #配置日志
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    #驼峰命名
    map-underscore-to-camel-case: true

基本xml文件

<?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="">

</mapper>

xml与mapper下的接口一一对应关系

告诉Springboot如何扫描到mapper包路径（在springbootApplicantion中添加注解）

@MapperScan("com.example.springboot1.mapper")　

创建service并且标注为Springboot里面的一个bean

package com.example.springboot1.service;

import org.springframework.stereotype.Service;

@Service
public class YongHuService {
}

mapper和Mapper.xml对应关系

 接口路径（/yonghu/selectAll）

 数据请求流程：前端浏览器->Springboot浏览器->Mybatis->Mysql->Java对象->Json对象->浏览器

通过注解查询单个用户

@Select("select * from yonghu where id=#{id}")
    YongHu selectById(Integer id);

接口传参方式

 @PathVariable

 @RequestParam

传递多个参数

/**
     * 查询单个
     * @return
     */
    @GetMapping("/selectOne")
    public Result selectOne(@RequestParam Integer id,@RequestParam(required = false) String xingBie){
        YongHu yongHu1=yongHuService.selectById(id);
        return Result.success(yongHu1);
    }　

 参数传递

 分页查询，引入pagehelper插件

 

<!--分页插件pageHelper -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>1.4.6</version>
            <exclusions>
                <exclusion>
                    <groupId>org.mybatis</groupId>
                    <artifactId>mybatis</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

在Service里面通过三行代码实现分页查询

public PageInfo<YongHu> selectPage(Integer pageNum,Integer pageSize){
        PageHelper.startPage(pageNum,pageSize);
        List<YongHu> list=yongHuMapper.selectAll();
        return PageInfo.of(list);
    }

分页接口

/**
     * 分页查询
     * @param pageNum 当前页码
     * @param pageSize 每页个数
     * @return
     */
    @GetMapping("/selectPage")
    public Result selectPage(@RequestParam(defaultValue = "1") Integer pageNum,
                             @RequestParam(defaultValue = "10") Integer pageSize){
        PageInfo<YongHu> pageInfo=yongHuService.selectPage(pageNum,pageSize);
        return Result.success(pageInfo);
    }

 使用Mybatis实现增删改操作

GET：查询；POST：新增；PUT：修改；DELETE：删除； @RequstBody可以把前端传来的Json字符串映射成Java对象或者数组

Mybatis里面写sql使用下划线，涉及到绑定Java对象值就写驼峰

<insert id="add" parameterType="com.example.springboot1.entity.YongHu">
        insert into yonghu (addtime,yonghuzhanghao,mima,yonghuxingming,xingbie,lianxifangshi,shenfenzheng,youxiang,touxiang)
        values (#{addTime},#{yongHuZhangHao},#{miMa},#{yongHuXingMing},#{xingBie},#{lianXiFangShi},#{shenFenZheng},#{youXiang},#{touXiang})
    </insert>

<update id="updateById" parameterType="com.example.springboot1.entity.YongHu">
        update yonghu set addtime=#{addTime},yonghuzhanghao=#{yongHuZhangHao},mima=#{miMa},yonghuxingming=#{yongHuXingMing},xingbie=#{xingBie},
                          lianxifangshi=#{lianXiFangShi},shenfenzheng=#{shenFenZheng},youxiang=#{youXiang},touxiang=#{touXiang}
        where id=#{id}
    </update>

@Delete("delete from yonghu where id=#{id}")
    void deleteById(Integer id);

/**
     * 新增数据
     * @param yongHu
     * @return
     */
    @PostMapping("/add")
    public Result add(@RequestBody YongHu yongHu){
        yongHuService.add(yongHu);
        return Result.success();
    }

    /**
     * 更新数据
     * @param yongHu
     * @return
     */
    @PutMapping("/update")
    public Result update(@RequestBody YongHu yongHu){
        yongHuService.update(yongHu);
        return Result.success();
    }

    /**
     * 删除数据
     * @param id
     * @return
     */
    @DeleteMapping("/deleteById/{id}")
    public Result deleteById(@PathVariable Integer id){
        yongHuService.deleteById(id);
        return Result.success();
    }
    /**
     * 查询所有
     * @return
     */
    @GetMapping("/selectAll")
    public Result selectAll(){
        List<YongHu> list=yongHuService.selectAll();
        return Result.success(list);
    }

Resouce.getResouceAsSteam("sqlMapConfig.xml")factory=new ...Builder.build(is)sqlSession =factory.openSession(true);