c# - Cloning Object with many-to-many relationship in EntityFramework -

c# - Cloning Object with many-to-many relationship in EntityFramework -

all want create exact re-create of object.

i have class

[serializable] public class project { public int id { get; set; } public string name { get; set; } //navigational fields.. public virtual list<businessrequirement> businessrequirements { get; set; } }

and another

[serializable] public class businessrequirement { public int id { get; set; } public string name { get; set; } public string description { get; set; } public virtual list<project> projects { get; set; } }

so somewhere i've configured many-to-many relationship b/w project , businessrequirement this:

hasmany(s => s.businessrequirements) .withmany(s => s.projects) .map(m => { m.mapleftkey("projectid"); m.maprightkey("businessrequirementid"); m.totable("projectbusinessrequirementmapping"); });

and i've made dbcontext static i.e.

public static class datalayer { public static mydbcontext db; }

now, m doing is, trying create re-create of object of project i.e.

public project clone(project source) { project target = new project(); target.name = source.name; //1. // target = source; //2. target.businessrequirements = new list<businessrequirement>(); foreach(businessrequirement br in source.businessrequirements) { businessrequirement nbr = datalayer.get<businessrequirement>(s=>s.id=br.id).singleordefault(); if(nbr!=null) target.businessrequirements.add(nbr); } //3. //target.businessrequirements = source.businessrequirements; //4. //target.businessrequirements = new list<businessrequirement>(); //foreach(businessrequirement br in source.businessrequirements) //{ // businessrequirement nbr = br; // if(nbr!=null) // target.businessrequirements.add(nbr); //} homecoming target; }

none of 4 methods work properly.

the 1 closest working 2, unusual thing happens. now, if add together businessrequirements original project, gets added clonned one , vice-versa, same goes deletion.

somehow, entityframework treating both projects one. though behavior occurs in many-to-many related navigational properties.

why entityframework behaving this???. missing? please help..

its been day, cannot work.

i have tried this, this, this , this didn't work either..

you can utilize fact adding object context changes state of kid objects in object graph added:

project proj; using (var db = new mydbcontext()) { // fetch detached project , populate businessrequirements. proj = db.projects.asnotracking().include(p => p.businessrequirements) .first(p => p.id == source.id); db.projects.add(proj); db.savechanges(); }

by fetching source project asnotracking context not add together alter tracker , next line db.projects.add(proj); considers project , adhering kid objects brand new.

silently, renounced strategy work 1 static context. it's different topic, should not that. contexts supposed have short life span.

c# linq clone entity-framework-5