<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

    <properties resource="db.properties"/>

    <typeAliases>

        <!-- 为实体类me.gacl.domain.User配置一个别名_User -->

        <!-- <typeAlias type="me.gacl.domain.User" alias="_User"/> -->

        <!-- 为me.gacl.domain包下的所有实体类配置别名，MyBatis默认的设置别名的方式就是去除类所在的包后的简单的类名

        比如me.gacl.domain.User这个实体类的别名就会被设置成User

         -->

        <package name="com.cn.liubb"/>

    </typeAliases>

    <environments default="development">

        <environment id="development">

            <transactionManager type="JDBC" />

            <!-- 配置数据库连接信息 -->

            <dataSource type="POOLED">

                <property name="driver" value="${driver}"/>

                <property name="url" value="${url}" />

                <property name="username" value="${name}" />

                <property name="password" value="${password}" />

            </dataSource>

        </environment>

    </environments>

    <mappers>

        <!-- 注册userMapper.xml文件，

        userMapper.xml位于me.gacl.mapping这个包下，所以resource写成me/gacl/mapping/userMapper.xml-->

        <mapper resource="mapperxml/userMapper.xml"/>

        <mapper resource="mapperxml/classMapper.xml"/>

        <!-- 注册UserMapper映射接口-->

        <mapper class="com.cn.liubb.UserMapperI"/>

    </mappers>

    <!-- 配置实体类的别名，配置实体类别名的目的是为了在引用实体类时可以使用实体类的别名来代替实体类，达到简写的目的 -->

</configuration>

<?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">

<!-- 为这个mapper指定一个唯一的namespace，namespace的值习惯上设置成包名+sql映射文件名，这样就能够保证namespace的值是唯一的

例如namespace="me.gacl.mapping.classMapper"就是me.gacl.mapping(包名)+classMapper(classMapper.xml文件去除后缀)

 -->

<mapper namespace="com.cn.liubb.classMapper">

<!--

        根据classId查询对应的班级信息,包括学生,老师

     -->

    <!--

    方式一: 嵌套结果: 使用嵌套结果映射来处理重复的联合结果的子集

    SELECT * FROM class c, teacher t,student s WHERE c.teacher_id=t.t_id AND c.C_id=s.class_id AND  c.c_id=1

     -->

    <select id="getClass3" parameterType="int" resultMap="ClassResultMap3">

        select * from class c, teacher t,student s where c.teacher_id=t.t_id and c.C_id=s.class_id and  c.c_id=#{id}

    </select>

    <resultMap type="com.cn.liubb.Classes" id="ClassResultMap3">

        <id property="id" column="c_id"/>

        <result property="name" column="c_name"/>

        <association property="teacher" column="teacher_id" javaType="com.cn.liubb.Teacher">

            <id property="id" column="t_id"/>

            <result property="name" column="t_name"/>

        </association>

        <!-- ofType指定students集合中的对象类型 -->

        <collection property="students" ofType="com.cn.liubb.Student">

            <id property="id" column="s_id"/>

            <result property="name" column="s_name"/>

            <result property="classid" column="c_id"/>

        </collection>

    </resultMap>

    <!--

        方式二：嵌套查询：通过执行另外一个SQL映射语句来返回预期的复杂类型

            SELECT * FROM class WHERE c_id=1;

            SELECT * FROM teacher WHERE t_id=1   //1 是上一个查询得到的teacher_id的值

            SELECT * FROM student WHERE class_id=1  //1是第一个查询得到的c_id字段的值

     -->

     <select id="getClass4" parameterType="int" resultMap="ClassResultMap4">

        select * from class where c_id=#{id}

     </select>

     <resultMap type="com.cn.liubb.Classes" id="ClassResultMap4">

        <id property="id" column="c_id"/>

        <result property="name" column="c_name"/>

        <association property="teacher" column="teacher_id" javaType="com.cn.liubb.Teacher" select="getTeacher2"></association>

        <collection property="students" ofType="com.cn.liubb.Student" column="c_id" select="getStudent"></collection>

     </resultMap>

     <select id="getTeacher2" parameterType="int" resultType="com.cn.liubb.Teacher">

        SELECT t_id id, t_name name FROM teacher WHERE t_id=#{id}

     </select>

     <select id="getStudent" parameterType="int" resultType="com.cn.liubb.Student">

        SELECT s_id id, s_name name, class_id classid FROM student WHERE class_id=#{id}

     </select>

    <select id="getUserCount" parameterMap="getUserCountMap" statementType="CALLABLE">

        CALL PRO4(?,?)

    </select>

    <parameterMap type="java.util.Map" id="getUserCountMap">

        <parameter property="ptno" mode="IN" jdbcType="INTEGER"/>

        <parameter property="cou" mode="OUT" jdbcType="INTEGER"/>

    </parameterMap>

     </mapper>