c# - Why is EDM class a partial class -


i added new ado.net edm item in visual studio porject.

using system; using system.data.entity; using system.componentmodel.dataannotations.schema; using system.linq; using system.diagnostics;  namespace rajat.personal.ef {     public partial class practicecontext : dbcontext     {         public practicecontext()             : base("name=localcontext")         {             this.database.log = s => debug.writeline(s);         }      public virtual dbset<user> users { get; set; }      protected override void onmodelcreating(dbmodelbuilder modelbuilder)     {         modelbuilder.entity<user>()             .property(e => e.firstname)             .isunicode(false);          modelbuilder.entity<user>()             .property(e => e.lastname)             .isunicode(false);          modelbuilder.entity<user>()             .property(e => e.emailaddress)             .isunicode(false);          modelbuilder.entity<user>()             .property(e => e.password)             .isunicode(false);     } }

}

i have 2 questions

  1. why practicecontext partial class?
  2. why users property virtual ?

it generated partial class can extend class in separate file , avoid losing edits you've made when context next regenerated.

it uses virtual on properties can override them in inherited class provide alternative behaviour.


Comments

Post a Comment

Popular posts from this blog

c# - Update a combobox from a presenter (MVP) -

i using mvp in project, new in mvp. have 2 comboboxes. when select option in combobox, combobox should filled new data. this action in presenter. view 'view1' in presenter, , introduced combobox1 , combobox2 properties in 'view1', because need 'datasource', 'displaymember', 'valuemember' , 'refresh()' in method below. but, when using pattern, enough send property like public string combobox2 { { return combobox1.selectedvalue.tosstring(); } } into presenter not whole combobox. how can solve problem? public void onselectedindexchangedcombobox1() { if (view1.combobox1.selectedindex == -1) { return; } datatable dt = tools.getdatatable("a path"); var query = (from o in dt.asenumerable() o.field<string>("afield") == farmerview.combobox1.selectedvalue.tostring() orderby o.field<string>("anotherfield") select...
Read more

How to understand 2 main() functions after using uftrace to profile the C++ program? -

i trying uftrace profile following simple c++ program: #include <iostream> class { public: a() {std::cout << "a created" << std::endl;} ~a() {std::cout << "a destroyed" << std::endl;} }; int main() { a; return 0; } the profile result this: # uftrace a.out created destroyed # duration tid function 2.026 [ 4828] | __cxa_atexit(); [ 4828] | main() { [ 4828] | __static_initialization_and_destruction_0() { 89.397 [ 4828] | std::ios_base::init::init(); 0.768 [ 4828] | __cxa_atexit(); 93.029 [ 4828] | } /* __static_initialization_and_destruction_0 */ 94.425 [ 4828] | } /* main */ [ 4828] | main() { [ 4828] | a::a() { 11.104 [ 4828] | std::operator <<(); 10.825 [ 4828] | std::basic_ostream::operator <<(); 24.514 [ 4828] | } /* a::a */ [ 4828] | a::~a() { 0.978 [ 4828] | ...
Read more

android - Unable to generate FCM token from dynamically instantiated Firebase -

our business logic requires instantiate firebase during runtime. fetch firebase credentials (app id, api key etc.) default firebase location after knowing user's public key , create firebase instance using credentials. this means there 2 firebase instances used within app: the default "index" firebase gives credentials second the actual firebase intend use point forward the second firebase initialised this: firebaseapp app = firebaseapp.initializeapp(<context>, <options>, <app_label>); our problem traditional method of retrieving fcm token using firebaseinstanceidservice , ontokenrefresh() fails since ontokenrefresh() method called first firebase instance. directly calling string token = firebaseinstanceid.getinstance(app).gettoken(); returns null never ready when called. have tried polling test if token generated @ point. no luck. how can generate fcm token reliably firebase instance instantiated during runtime? i...
Read more