摘要: mysql.help_topic 利用help_topic表把以逗号分隔的字符串转换成行。 SELECT substring_index(substring_index( a.rn,',',b.help_topic_id + 1 ),',' ,- 1) AS rn FROM (select '1,2 阅读全文
posted @ 2021-01-19 14:41 imnet 阅读(685) 评论(1) 推荐(0)