对mysql来说，timeStamp类型使用DATE_FOMAT转化来进行判断，oracle采用TO_CHAR
<choose>
<when test="dbtype==mysql">
AND DATE_FORMAT(COMMENT_TIME, ‘%Y-%m-%d %H:%i:%s‘) >= #{beginDate}
</when>
<otherwise>
AND TO_CHAR(COMMENT_TIME,‘yyyy-mm-dd HH24:MI:SS‘) >= #{beginDate}
</otherwise>
</choose>