Mybatis基础

<?xml version="1.0" encoding="UTF-8" ?>  
<!DOCTYPE configuration PUBLIC "-//ibatis.apache.org//DTD Config 3.0//EN" 
    "http://ibatis.apache.org/dtd/ibatis-3-config.dtd">
<configuration>
    <environments default="environment">
        <environment id="environment">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" 
                    value="oracle.jdbc.OracleDriver" />
                <property name="url"
                    value="jdbc:oracle:thin:@192.168.160.253:1521:orcl" />
                <property name="username" value="openlab" />
                <property name="password" value="open123" />
            </dataSource>
        </environment>
    </environments>  
    <!-- 引入 Dept.xml 配置 -->
    <mappers>
        
        <mapper resource="com/tarena/entity/Dept.xml"/>
         
    </mappers>
</configuration> 

<?xml version="1.0" encoding="UTF-8" ?>
<!-- Dept.xml 在com.tarena.entity 包中  -->  
<!DOCTYPE mapper PUBLIC "-//ibatis.apache.org//DTD Mapper 3.0//EN"      
 "http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd">
<!-- namespace 的值是 DeptMapper 接口
  每个Mapper 接口对应一个配置文件  -->
<mapper 
    namespace="com.tarena.entity.DeptMapper">
    <insert id="addDept" 
        parameterType="com.tarena.entity.Dept">
        <selectKey keyProperty="deptno"
            order="BEFORE"
            resultType="int">
            select SEQ_T_DEPT.nextval 
            from DUAL
        </selectKey>
            insert into T_DEPT (deptno, dname, 
            loc) values 
            (#{deptno}, #{dname}, #{loc})
    </insert>
    <delete id="deleteDept"
        parameterType="com.tarena.entity.Dept">
        delete from T_DEPT 
        where deptno = #{deptno}
    </delete>
    <select id="findDeptById"
        parameterType="java.lang.Integer"
        resultType="com.tarena.entity.Dept">
        select deptno,dname,loc 
        from T_DEPT where deptno=#{deptno}
    </select>
    <update id="updateDept"
        parameterType="com.tarena.entity.Dept">
        <!-- #{deptno} 读取参数的Bean属性 -->
        update T_DEPT set dname=#{dname},
        loc = #{loc} where deptno=#{deptno}
    </update>
    <!-- 注意resultType 的值是List中元素类型
     结果集行映射的数据类型-->
    <select id="findAllDept"
        resultType="com.tarena.entity.Dept">
        select deptno, dname, loc 
        from T_DEPT
    </select>
    <select id="findDeptByLoc"
        parameterType="java.lang.String"
        resultType="com.tarena.entity.Dept">
        select deptno, dname, loc 
        from T_DEPT where loc=#{loc}
    </select>
    <select id="findAllDname"
        parameterType="java.lang.String"
        resultType="java.util.Map">
        select dname from T_DEPT
        where loc=#{loc}
    </select>
</mapper>