标签：index 函数 http img replace ima sql sub sel
SELECT substring_index(substring_index(a.chain,‘_‘,b.help_topic_id + 1 ), ‘_‘ ,- 1 ) AS ID FROM (select ‘1_11_1223_1242‘ as chain) a JOIN mysql.help_topic b ON b.help_topic_id < (length(a.chain) - length( replace(a.chain, ‘_‘, ‘‘) ) + 1)
标签：index 函数 http img replace ima sql sub sel
原文地址：https://www.cnblogs.com/star521/p/13500746.html
