Checking referential integrity rule violation before deletion

Question

Before deleting a row from a table, is there any simple way to check that it would violate a referential integrity rule? I'd like to do this from a C# win form application (.Net 3.5) using SQL Server 2005.

Answer 1

You might do the delete inside a transaction:

try
{
  begin transaction
  delete row
}
catch SQLException
{
  if SQL error indicates referential integrity violation
    throw ReferentialIntegrityViolationException
}
finally
{
  rollback transaction
}

(assuming you never want the delete to take place at this point in your code)

Answer 2

There are a few potential options that come to mind:

• Set up cascading deletes in the database so that a delete will always succeed.
• Check for related records with SELECTs before deleting. This requires that the application have knowledge of the constraints.
• A good domain model (business classes) should allow the application to be aware of related records.
• An O/R Mapper, such as NHibernate, can be used to define cascade delete operations.
• Use SMO (Microsoft.SqlServer.Smo) to inspect the database schema for relations, then check for existing related records. I don't know if that's possible.