What does this statement do @@RowCount > 0
entity-framework, sql-server, t-sql
Solution
`@@Rowcount` is a special variable. It will always hold the number of records changed or returned by the last statement. In this case, the last statement was the insert. By using `@@Rowcount > 0` in the where clause, you make sure the select only matches any records if the insert statement succeeded.
If they had used `@@Rowcount > 1` instead, that statement would never be true. That insert statement will only insert 1 row. 1 is not > 1.
Problem
Taken from the book : "Julia Lerman - Programming Entity Framework " when creating a new entity in EF : ``` var contact = Contact.CreateContact(0, "Camey", "Combs", DateTime.Now, DateTime.Now); context.Contacts.AddObject(contact); context.SaveChanges(); ``` The generated sql : ``` exec sp_executesql N'insert [dbo].[Contact]([FirstName], [LastName], [Title], [AddDate], [ModifiedDate]) values (@0, @1, null, @2, @3) select [ContactID] from [dbo].[Contact] where @@ROWCOUNT > 0 and [ContactID] = scope_identity()', N'@0 nvarchar(50),@1 nvarchar(50),@2 datetime2(7),@3 datetime2(7)', @0=N'Camey',@1=N'Combs',@2='2009-08-30 09:27:31.7449098', @3='2009-11-30 09:27:31.7449098' ``` What is @@RowCount > 0 used for in the where clause ? I'm not sure of what it does according to msdn it returns the number of affected rows , so as i understand it , this is just a way the verify that the Contact record was added they could of also have written @@ROWCOUNT = 1 is this correct ?