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）

java 复制代码

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 复制代码

<?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.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} and
                                entrydate between #{begin} and #{end} order by update_time desc
    </select>
</mapper>