摘要：
0.查看磁盘情况--确定data目录放在哪个文件夹下 fdisk -l lsblk 1.关闭防火墙 systemctl disable firewalld 2.解压安装包 .tar.xz 上传安装包 /usr/local/ xz -d mysql-5.7.24-linux-glibc2.12-x86 阅读全文
摘要：
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_t 阅读全文