csdndz的博客

Oracle查询各组最大值的前几位、最小值的前几位和出现次数SELECT b.* FROM ( SELECT a.CODE, a.VALUE, COUNT( a.VALUE ) count, ROW_NUMBER ( ) OVER ( PARTITION BY a.CODE ORDER BY a.VALUE DESC ) maxrn, ROW_NUMBER ( ) OVER ( PARTITION BY a.CODE ORDER BY a.VALUE ) minrn FROM

需求：对如下数据排序：思路一：将字母转成ASCII码值进行排序(最开始想到的这个思路，但该方法待优化！！！)ORDER BY CASE WHEN ASCII(字段) < 58 THEN TO_NUMBER(字段) ELSE ASCII(字段) END[0-9]的ASCII码值为[48-57][A-Z]的ASCII码值为[65-90][a-z]的ASCII码值为[97-122]这里直接判断小于58就认为是数字，数字时取数值，数字大于65时就会和字母冲突，当前业务中数字最大为20（无