1、查询用户
<select id="getUser" parameterType="int">
select user_name,password from table users where id = #{id}
</select>
2. 新增用户
<insert id="addUser" parameterType="xxx.xxx.User">
insert into users (user_name,password) values (#{userName} ,#{password})
</insert>
3. 更新用户
