例子:
survivor table
owner_id unique_id isDead
|__________ |__________|__________
| foreign key | |
| 1234 ------------> | 1234 | true <--- this row is referenced
|__________ |__________|__________
| |
| 1234 | false <--- this row should be referenced
|__________|__________
目前代码是这样的:
CONSTRAINT `key_2` FOREIGN KEY (`owner_id`) REFERENCES `survivor` (`unique_id`)
我想让它的功能是这样的:
CONSTRAINT `key_2` FOREIGN KEY (`owner_id`) REFERENCES `survivor` (`unique_id`) WHERE `isDead` = false
但这显然是不可能的。
有谁知道我如何实现这样的目标?