MySql数组类型和默认值

Question

我需要像那样添加具有默认值的字段

`setting_notification` = 'a:2:{s:19:"other_notifications";i:1;s:21:"message_notifications";i:0;}' 

ALTER TABLE app_users ADD setting_notification tinytext COLLATE utf8_unicode_ci NOT NULL COMMENT '(DC2Type:array)'

如何做到这一点？

我试试这个

ALTER TABLE app_users 
ADD setting_notification LONGTEXT CHARACTER SET utf8 
DEFAULT 'a:2:{s:19:"other_notifications";i:1;s:21:"message_notifications";i:0;}'  
COMMENT '(DC2Type:array)'

有错误

 [Err] 1101 - BLOB, TEXT, GEOMETRY or JSON column 'setting_notification' can't have a default value

然后像那样尝试

ALTER TABLE app_users 
ADD setting_notification tinytext 
DEFAULT "a:2:{s:19:\"other_notifications\";i:1;s:21:\"message_notifications\";i:0;}" 
COLLATE utf8_unicode_ci 
NOT NULL COMMENT '(DC2Type:array)'

还是有错误

[Err] 1101 - BLOB, TEXT, GEOMETRY or JSON column 'setting_notification' can't have a default value

SQL 版本

mysql> SELECT VERSION();
+-------------------------+
| VERSION()               |
+-------------------------+
| 5.7.16-0ubuntu0.16.04.1 |
+-------------------------+
1 row in set (0,01 sec)

Answer 1

您可以添加默认值。为什么使用 tinytext 而不是 varchar？

ALTER TABLE app_users ADD setting_notification varchar(255) DEFAULT "a:2:{s:19:\"other_notifications\";i:1;s:21:\"message_notifications\";i:0;}" COLLATE utf8_unicode_ci NOT NULL COMMENT '(DC2Type:array)'