How do I use cascade delete with SQL Server?

Question

I have 2 tables: T1 and T2, they are existing tables with data. We have a one to many relationship between T1 and T2. How do I alter the table definitions to perform casca

Answer 1

If the one to many relationship is from T1 to T2 then it doesn't represent a function and therefore cannot be used to deduce or infer an inverse function that guarantees the resulting T2 value doesn't omit tuples of T1 join T2 that are deductively valid, because there is no deductively valid inverse function. ( representing functions was the purpose of primary keys. ) The answer in SQL think is yes you can do it. The answer in relational think is no you can't do it. See points of ambiguity in Codd 1970. The relationship would have to be many-to-one from T1 to T2.