ibatis相关

<?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">
<!-- namespace:表示名称空间。现在的目的是区分id的. -->
<mapper namespace="com.zhiyou100.zhl.dao.UsersDao">
    <!-- 根据id查询用户。id:标识该标签。
             parameterType:参数类型。可以写 也可以省略
             resultType:返回结果的类型。
             
            #{id}:类似于EL表达式。 解析id的值
     -->
    
    <select id="selByAge" parameterType="map" resultType="com.zhiyou100.zhl.bean.Users">
        <![CDATA[select * from users where age>=#{min} and age<=#{max}]]>
    </select> 
    
    <select id="getUser" parameterType="int" resultType="com.zhiyou100.zhl.bean.Users">
          select * from users where id=#{id};
    </select>
    
    <insert id="addUser" parameterType="com.zhiyou100.zhl.bean.Users" useGeneratedKeys="true" keyProperty="id">
        insert into users(name,age) value(#{name},#{age});
    </insert>
    
    <delete id="delUser" parameterType="int">
        delete from users where id=#{id};
    </delete>
    
    <update id="updateUser" parameterType="com.zhiyou100.zhl.bean.Users">
        update users set name=#{name},age=#{age} where id=#{id};
    </update>
    
    <select id="selAll" resultType="com.zhiyou100.zhl.bean.Users">
        select * from users order by${columnName};
    </select>
</mapper>

@Test
    void testAdd() {
        Users u=new Users("什么",21);
        usersdao.addUser(u);
        System.out.println(u.getId());
    }