資料，資料，命根就在資料 ! 操作資料庫時，一定要謹慎小心。師萬物 的程式碼看看就好，要有自己的判斷。遇到抉擇，要不恥上下問。

example

stu@Ubuntu:~$ mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 88
Server version: 8.0.12 MySQL Community Server - GPL

Copyright (c) 2000, 2018, Oracle and/or its affiliates.
 
 All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> create database if not exists db_herbal_medicine;
Query OK,
 
 1 row affected, 1 warning (0.00 sec)

mysql> warnings;
Show warnings enabled.
mysql> create database if not exists db_herbal_medicine;
Query OK, 1 row affected, 1 warning (0.00 sec)

Note (Code 1007): Can't create database 'db_herbal_medicine'; database exists
mysql> exit
Bye
stu@Ubuntu:~$ 

more knowledge

• 在[2]中提到的：\W 與 \w。
• 基於MySQL8的命令執行效果如下

stu@Ubuntu:~$ mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 90
Server version: 8.0.12 MySQL Community Server - GPL

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> \W
Show warnings enabled.
mysql> \w
Show warnings disabled.
mysql> exit
Bye
stu@Ubuntu:~$ 

reference

resource

MySQL是一個關係型資料庫管理系統，目前是開源的(2018-10)。
許可權明確，引擎與字符集等選擇恰當，命名規範。
MariaDB，Redis，MongoDB，PostgreSQL，Hive，HBase等，多作了解，拓寬心量。
Workbench，phpMyAdmin，Navicat等圖形化管理工具，豫兮若冬涉川。