Oracle和Mysql获取uuid的方法对比

场景：orm框架用mybatis，需要往数据库新增一条数据，用Oracle和mysql数据库分别需要怎么实现？

mysql方法，用mysql提供的uuid函数

<insert id="add" parameterType="com.t.model.ActionModel" databaseId="mysql">
        insert into t_config
        (uuid, `condition`, flag, create_time, project_name,tips,status,tf_name,parent_flag)
        values 
        (uuid(),#{condition},#{flag},#{createTime},#{projectName},#{tips},#{status},#{tfName},#{parentFlag})
    </insert>

oracle方法，主要用神奇的dual，select sys_guid() from dual

<insert id="add" parameterType="com.t.model.ActionModel" databaseId="oracle">
        <selectKey keyProperty="uuid" resultType="java.lang.String" order="BEFORE">
            select sys_guid() from dual
        </selectKey>
        insert into  t_config
        (uuid, condition, flag,  create_time, project_name,tips,status,tf_name,parent_flag)
        values 
        (#{uuid},#{condition},#{flag},#{createTime},#{projectName},#{tips},#{status},#{tfName},#{parentFlag})
    </insert>