您有一个子表，其中包含来自同一父级的 2 个级联路径:一个删除"，一个空".

You have a child table with 2 cascade paths from the same parent: one "delete", one "null".

什么优先?之后你期待什么?等等

What takes precedence? What do you expect afterwards? etc

注意:触发器是代码，可以为级联添加一些智能或条件.

Note: A trigger is code and can add some intelligence or conditions to a cascade.