如何检查 created_in 列是否为 none 或不在触发器内？

Question

用户table

中的列和触发器结构

CREATE TABLE `users` (
 `created_in` datetime NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci

Trigger	Event	Table	Statement	Timing
...	insert	users	IF NEW.created_in = "" THEN SIGNAL SQLSTATE "45000"; END IF	before

如果 created_in 列是 none 但不起作用，我正在尝试取消插入。

如何检查 created_in 列是否为 none？

Version of MySQL is 5.7

Answer 1

不需要触发器，会话严格模式就足够了：

set session sql_mode = '';

CREATE TABLE `users` (
 `created_in` date NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
insert into users values ('');
select * from users;

| created_in |
| :--------- |
| 0000-00-00 |

set session sql_mode = 'STRICT_ALL_TABLES';

insert into users values ('');

Incorrect date value: '' for column 'created_in' at row 1

db<>fiddle here

如何检查 created_in 列是否为 none 或不在触发器内？

How can I check if the created_in column is none or not inside triggers?

mysql

sql

triggers