1、在Shell中执行MySQL相关查询

通过参数-e

[root@node1 ~]# mysql -uroot -p123456 -e "show databases"
mysql: [Warning] Using a password on the command line interface can be insecure.
+--------------------+
| Database           |
+--------------------+
| employees          |
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
[root@node1 ~]# mysql -uroot -p123456 -e "select count(1) from employees.employees"
mysql: [Warning] Using a password on the command line interface can be insecure.
+----------+
| count(1) |
+----------+
|   300024 |
+----------+
[root@node1 ~]# 

2、在MySQL命令行中执行Shell相关命令

system + 系统shell命令，不需要分号

mysql> system date
2021年 11月 15日 星期一 00:36:50 EST
mysql> system pwd
/root
mysql> system ls /
app  bin  boot  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var
mysql>