详解Mybatis（五）Mapper接口

<?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.usermapper" 就是me.gacl.mapping(包名)+usermapper(usermapper.xml文件去除后缀)

  -->

<mapper namespace= "mybatis.domain.mapper.usermapper" >

   <resultmap type= "user" id= "baseresultmap" >

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

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

     <result column= "t_salary" property= "salary" />

   </resultmap>

   <!-- 保存操作 -->

   <insert id= "save" usegeneratedkeys= "true" keyproperty= "id" >

       insert into t_user (name , salary)    values (#{name},#{salary}) 

   </insert>

   <!-- 更改操作 -->

   <update id= "update" >

     update t_user where name=#{name},salary=#{salary} where id=#{id}

   </update>

   <!-- 删除操作 -->

   <delete id= "delete" >

     delete from t_user where id=#{id}

   </delete>

   <!-- 查询单个操作 -->

   <select id= "select" parametermap= "java.lang.long" resulttype= "mybatis.domain.user" >

     select * from t_user where id = #{id}

   </select>

     <!-- 查询多个操作 -->

     <select id= "selectall" resulttype= "user" >

         select id,name,salary from t_user

     </select> 

</mapper>

import java.util.list;

import mybatis.domain.user;

public interface usermapper {

     void save(user u);

     void update(user u);

     void delete( long id);

     user select(user u);

     list<user> selectall();

}