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mysql8基礎 邏輯運算 or 或

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。