报错的原因就是
[root@localhost duanxinli]# journalctl -xe
-- Subject: Unit mysqld.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysqld.service has begun starting up.
12月 30 22:52:01 localhost.localdomain mysqld[7419]: 2018-12-30T14:52:01.435970Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timest
12月 30 22:52:01 localhost.localdomain mysqld[7419]: 2018-12-30T14:52:01.438425Z 0 [Note] /usr/sbin/mysqld (mysqld 5.7.24) starting as process 7422 ...
12月 30 22:52:01 localhost.localdomain mysqld[7419]: 2018-12-30T14:52:01.440408Z 0 [ERROR] Could not open file '/var/log/mysql/mysqld.log' for error logging: Permission denied
12月 30 22:52:01 localhost.localdomain mysqld[7419]: 2018-12-30T14:52:01.440434Z 0 [ERROR] Aborting
12月 30 22:52:01 localhost.localdomain mysqld[7419]: 2018-12-30T14:52:01.440479Z 0 [Note] Binlog end
12月 30 22:52:01 localhost.localdomain mysqld[7419]: 2018-12-30T14:52:01.440553Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
12月 30 22:52:01 localhost.localdomain systemd[1]: mysqld.service: control process exited, code=exited status=1
12月 30 22:52:01 localhost.localdomain mysqld[7419]: Initialization of mysqld failed: 0
12月 30 22:52:01 localhost.localdomain systemd[1]: Failed to start MySQL Server.
-- Subject: Unit mysqld.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysqld.service has failed.
--
-- The result is failed.
12月 30 22:52:01 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
12月 30 22:52:01 localhost.localdomain systemd[1]: mysqld.service failed.
12月 30 22:52:01 localhost.localdomain systemd[1]: mysqld.service holdoff time over, scheduling restart.
12月 30 22:52:01 localhost.localdomain systemd[1]: Stopped MySQL Server.
-- Subject: Unit mysqld.service has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysqld.service has finished shutting down.
12月 30 22:52:01 localhost.localdomain systemd[1]: start request repeated too quickly for mysqld.service
12月 30 22:52:01 localhost.localdomain systemd[1]: Failed to start MySQL Server.
-- Subject: Unit mysqld.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysqld.service has failed.
--
-- The result is failed.
12月 30 22:52:01 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
12月 30 22:52:01 localhost.localdomain systemd[1]: mysqld.service failed.
ESCOC
无权限，因为我用的是root用户，但是mysql执行的时候用的是mysql用户，所以无权限，需要授权！搞了一晚上操他妈的
