mysql基础 warnings 打开与关闭警告自动输出功能

原创云散月明 All China Database Union 2021-04-23

1679

OS : Ubuntu 18.04.1 LTS
DBMS : mysql 8.0.12

示例

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:~$

扩展

在[2]中提到的：\W 与 \w。
基于MySQL8的命令执行效果如下

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:~$