nested

Can you start a transaction in one stored procedure and then roll it back or commit it in a nested procedure? gbn Commit and rollback have different effects COMMIT decrements @@TRANCOUNT ROLLBACK pushes it back to zero This happens because SQL Server does not really support nested transactions. If you commit or rollback in a nested stored proc (not transaction), then you'll generate error 266 because of a @@TRANCOUNT mismatch on start and entry The rollback issue can be resolved by using SET XACT_ABORT ON which is "auto rollback" (simply) and suppresses error 266. The commit issue... you can't

I have the task to write own containers Linked_list and Array_list . I have one interface for them: typedef int value_type; class Container { public: class Iterator { public: Iterator(); Iterator(value_type* other); Iterator(const Iterator& other); Iterator& operator=(const Iterator& other); ... }; Container(); Container(const Container& other); ~Container(); virtual value_type& front() const=0; virtual value_type& back() const=0; virtual Iterator begin() const=0; // ... }; I did derived classes Linked_list and Array_list: class Linked_list:public Container { public: long int cur_size; List

How one can overload an operator<< for a nested private class like this one? class outer { private: class nested { friend ostream& operator<<(ostream& os, const nested& a); }; // ... }; When trying outside of outer class compiler complains about privacy: error: ‘class outer::nested’ is private You could make the operator<< a friend of outer as well. Or you could implement it completely inline in nested , e.g.: class Outer { class Inner { friend std::ostream& operator<<( std::ostream& dest, Inner const& obj ) { obj.print( dest ); return dest; } // ... // don't forget to define print (which

My nested resource is farm. In my routes I have: resources :users do resource :farm end devise_for :users, :path => 'accounts' So, the devise paths for sign up, etc are working and not making problems. But when I try to make a new farm, I get this error: undefined method `farm_user_path' for #<#<Class:0x463d8f8>:0x46493e8> I am accessing it via: <%= link_to "New Farm", new_user_farm_path(current_user) %> In my farm controller, I have: class FarmsController < ApplicationController # GET /farms # GET /farms.json include Devise::Controllers::Helpers helper_method :current_user def new @farm =

This question already has an answer here: C++ Forward declaring class scoped enumeration 1 answer I know that in C++11 it's possible to forward declare an enum type (if storage type is provided) e.g. enum E : short; void foo(E e); .... enum E : short { VALUE_1, VALUE_2, .... } But I would like to forward declare an enum defined within a class e.g. enum Foo::E : short; void foo(E e); .... class Foo { enum E : short { VALUE_1, VALUE_2, .... } } Is something like this possible in C++11 ? No, such a forward declaration isn't possible. [decl.enum]/5 (bold emphasis mine): If the enum-key is followed

I would like to know if I have something like this: def functionA(): with transaction.atomic(): #save something functionB() def functionB(): with transaction.atomic(): #save another thing Someone knows what will happen? If functionB fails, functionA will rollback too? Thank you! Yes, it will. Regardless of nesting, if an atomic block is exited by an exception it will roll back : If the block of code is successfully completed, the changes are committed to the database. If there is an exception, the changes are rolled back. Note also that an exception in an outer block will cause the inner block

I have two private nested classes that would need to access a private member in another class. I thought about putting the class that needs to access the private member as friend in the accessed class, however I'm getting an error that A::m_nData is private so I can't access it. Anyway of telling the compiler that I need to access the A::m_nData private member within D::DoSomething()? Here is a sample of what I'm trying to do: File A.h class A { class D; public: A(); ~A() {} private: friend class D; int m_nData; }; File A.cpp: #include "A.h" #include "B.h" A::A() : m_nData(0) { } File B.h: