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 這裡的程式碼看看就好，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 46
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> use employees;
Reading table information for
 
 completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> select * from departments;
+---------+--------------------+
| dept_no | dept_name          |
+---------+--------------------+
| d009    | Customer Service   |
| d005    | Development        |
 

| d002    | Finance            |
| d003    | Human Resources    |
| d001    | Marketing          |
| d004    | Production         |
| d006    | Quality Management |
| d008    | Research           |
| d007    | Sales              |
+---------+--------------------+
9 rows in set (0.01 sec)

mysql> select * from departments where dept_no=d007 or dept_name=Finance;
ERROR 1054 (42S22): Unknown column 'd007' in 'where clause'
mysql> select * from departments where dept_no='d007' or dept_name='Finance';
+---------+-----------+
| dept_no | dept_name |
+---------+-----------+
| d002    | Finance   |
| d007    | Sales     |
+---------+-----------+
2 rows in set (0.00 sec)

mysql> exit
Bye
stu@Ubuntu:~$ 

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，恰當選擇引擎與字符集，命名簡潔明瞭與規範。 MariaDB，Redis，MongoDB，PostgreSQL，Hive，HBase等，可以簡單地瞭解。 Workbench，phpMyAdmin，Navicat等圖形化管理工具，可以試用一下。