尝试如何添加ON DELETE CASCADE到一个现有的MySQL表，不丢弃任何现有数据

[ ^ ]。这是针对mySql但基于其他帖子，SQL Server也应该以类似的方式工作。

Try How to add ON DELETE CASCADE to an existing MySQL table without dropping any existing data
[^]. This is for mySql but based on other posts, SQL Server should also work in a similar fashion.