摘要：ERROR: "Can't create a new thread (errno 12); if you are not out of available memory, you can consult the manual for a possible OS-dependent bug" mysq 阅读全文

摘要：一、有主键去重 a、单字段重复 table ab 查询重复记录(一条) select aid from ab group by aid having count(*)>1 result: 查询重复记录(全部) select * from ab t where t.aid in(select aid 阅读全文