Rollback the inner transaction of nested transaction

Question

suppose I have following sql statement in sql server 2008:

BEGIN TRANSACTION    
SqlStatement1    
EXEC sp1    
SqlStatement3
COMMIT TRANSACTION

Answer 1

Rollback transaction on its own rolls back all transactions.

http://msdn.microsoft.com/en-us/library/ms181299(v=sql.100).aspx

The statement will still be executed - try this

create table #t (i int)
insert #t values (1)  -- t contains (1)

begin tran
    update #t set i = i +1
    select * from #t  -- t contains (2)
    begin tran
        update #t set i = i +1 
        select * from #t -- t contains (3)
    rollback tran  -- transaction is rolled back

select * from #t -- t contains (1)
update #t set i = i +1
select * from #t -- t contains (2)
commit    -- error occurs
select * from #t -- t contains (2)
drop table #t