二十六、Mybatis-XML映射文件

XML映射文件介绍

XML映射文件-MybatisX插件

XML映射文件与mybatis注解分别何时使用

XML映射文件总结

项目目录结构

EmpMapper（接口）（其中条件查询员工使用了xml映射，其余使用mybatis注解）

package com.itheima.mapper;import com.itheima.pojo.Emp;
import org.apache.ibatis.annotations.*;import java.time.LocalDate;
import java.util.List;@Mapper
public interface EmpMapper {//根据ID删除数据@Delete("delete from emp where id=#{id}")public void delete(Integer id);//新增员工@Options(useGeneratedKeys = true,keyProperty = "id")@Insert("insert into emp(username, name, gender, image, job, entrydate, dept_id, create_time, update_time)" +"values (#{username},#{name},#{gender},#{image},#{job},#{entrydate},#{deptId},#{createTime},#{updateTime})")public void insert(Emp emp);//更新员工@Update("update emp set username = #{username}, name = #{name}, gender = #{gender}, image = #{image}," +" job = #{job}, entrydate = #{entrydate}, dept_id = #{deptId},update_time = #{updateTime} where id = #{id}")public void update(Emp emp);//方案三: 开启mybatis的驼峰命名自动映射开关 --- a_cloumn ------> aColumn//根据ID查询员工@Select("select * from emp where id = #{id}")public Emp getById(Integer id);//条件查询员工public List<Emp> list(@Param("name") String name, @Param("gender") Short gender, @Param("begin") LocalDate begin ,@Param("end") LocalDate end);}

EmpMapper.xml文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.itheima.mapper.EmpMapper"><!--resultType:单条记录所封装的类型--><select id="list" resultType="com.itheima.pojo.Emp">select * from emp where name like concat('%',#{name},'%') and gender = #{gender} andentrydate between #{begin} and #{end} order by update_time desc</select>
</mapper>