VIPJAVA/02_JavaWeb/day07_mybatis/target/classes/com/lc/mapper/UserMapper.xml

<?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.lc.mapper.UserMapper">
    <!-- 单个参数
        输入参数省略
        #{id} 取值 可以是任意的
     -->
    <select id="getUserById" resultType="user" >
        select * from t_user where id = #{abc}
    </select>

    <!-- 多个参数
        注解 @Param
        方法中定义的key
        @Param("name") String name ,@Param("pass") String pass)
        取值 #{ Param 中 value 属性值 }
     -->
    <select id="getUserByNameAndPass" resultType="user" >
        select * from t_user where username = #{name} and password = #{pass}
    </select>


    <!-- 多个参数
        Map key value

        使用 #{key}
     -->
    <select id="getUserByNameAndGender" resultType="user" >
        select * from t_user where username = #{name} and gender = #{gender}
    </select>

    <!--
        默认
         key
            param1  param2
            arg0    arg1
     -->
    <select id="getUserByNameAndAddress" resultType="user" >
        select * from t_user where username = #{arg0} and address = #{arg1}
    </select>


    <!--
        #{} 可以对参数 编译 不会出现sql注入问题
        ${} 直接使用参数 拼接  有sql注入问题  慎用

        特殊情况
            传入的值 是一张表  或者是一个字段
     -->
    <select id="getUserByName" resultType="user" >
        select * from t_user where username = ${name}
    </select>
    
    <!-- resultmap -->
    <resultMap id="userByIdResultMap" type="com.lc.pojo.User">
        <!-- 主键配置 -->
        <id property="id" column="id"></id>

        <!-- result 其余字段 -->
        <result property="username" column="username" ></result>
<!--        <result property="password" column="password" ></result>-->
<!--        <result property="adderss" column="adderss" ></result>-->
<!--        <result property="gender" column="gender" ></result>-->
<!--        <result property="deptId" column="dept_id" ></result>-->

    </resultMap>
    
    <select id="getUserByIdResultMap" resultMap="userByIdResultMap">
        select * from t_user where id =#{id}
    </select>
</mapper>