他山之石，可以攻玉

<?xmlversion="1.0" encoding="UTF-8"?><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mappernamespace="com.example.prac4.dao.MenuDao"><resultMaptype="com.example.prac4.entity.Menu"id="MenuMap"><resultproperty="authority"column="authority"jdbcType="VARCHAR"/><resultproperty="router"column="router"jdbcType="VARCHAR"/><resultproperty="description"column="description"jdbcType="VARCHAR"/></resultMap><selectid="queryById"resultMap="MenuMap">        select authority,
               router,
               description
        from menu
        where authority = #{authority}
</select><deleteid="deleteById">        delete from authentication where authority = #{authority}
</delete><updateid="update">        update authentication
<set><iftest="username != null and username != ''">                username = #{username},count=count+1
</if></set>        where authority = #{authority}
</update><insertid="insert"keyProperty="authority"useGeneratedKeys="true">        insert into authentication(username)
        values (#{username})
</insert></mapper>