摘要：s = 'hellobaby' def findchar(s): for i in s: if s.count(i)==1: return i, s.index(i) m,n=findchar(s) print('第一个出现一次的字符是{}，位置是{}'.format(m,n)) 阅读全文

摘要：SELECT procpid, start, now() - start AS lap, current_query FROM (SELECT backendid, pg_stat_get_backend_pid(S.backendid) AS procpid, pg_stat_get_backen 阅读全文

摘要：kill方式是杀掉进程，但是有时候需要取消相关SQL语句，采用以下方式：查看哪些SQL语句正在执行，语句如下：SELECT datname,procpid,query_start, current_query,waiting,client_addr FROM pg_stat_activity WHE 阅读全文

摘要：What you have is a float literal without the trailing zero, which you then access the __truediv__method of. It's not an operator in itself; the first 阅读全文