>I created this stored proc:
>
>

>
>CREATE PROCEDURE wit_DeleteCompany
>	@CompanyKey	int
>AS
>
>BEGIN
>
>	-- If the company key does not exist in the clients table...
>	IF NOT EXISTS(SELECT CompanyKey
>					FROM wit_Clients
>					WHERE CompanyKey = @CompanyKey)
>
>		BEGIN
>
>			-- Delete the address records
>			DELETE FROM wit_Addresses
>				WHERE AddressKey IN
>					(SELECT AddressKey
>						FROM wit_CompanyAddresses
>						WHERE CompanyKey = @CompanyKey)
>
>			-- Delete the CompanyAddress link table records
>			DELETE FROM wit_CompanyAddresses
>				WHERE CompanyKey = @CompanyKey
>
>			-- Delete the company record
>			DELETE 
>				FROM wit_CompanyInfo
>				WHERE CompanyKey = @CompanyKey
>
>		END
>
>	ELSE
>
>		RAISERROR('Company key is in use and cannot be deleted', 18, 0)
>
>	END
>

>
>It ensures that a company is not in use before deleting it.
>
>1) Is there anything wrong with doing it this way

I would put 3 delete statements inside explicit transaction

>2) How do you differentiate in you C# app between this kind of issue and a real error.

You can catch SQLException separately to other exceptions.