.net - The model backing the <Database> context has changed since the database was created -

the error message :

"the model backing 'addressbook' context has changed since database created. either manually delete/update database, or call database.setinitializer idatabaseinitializer instance. example, recreatedatabaseifmodelchanges strategy automatically delete , recreate database, , optionally seed new data."

i trying use code-first feature , following wrote:

var modelbuilder = new modelbuilder(); var model = modelbuilder.createmodel(); using (addressbook context = new addressbook(model)) {     var contact = new contact     {         contactid = 10000,         firstname = "brian",         lastname = "lara",         modifieddate = datetime.now,         adddate = datetime.now,         title = "mr."      };     context.contacts.add(contact);     int result = context.savechanges();     console.writeline("result :- "+ result.tostring()); } 

the context class:

public class addressbook : dbcontext {     public addressbook()     { }     public addressbook(dbmodel addressbook)         : base(addressbook)     {      }     public dbset<contact> contacts { get; set; }     public dbset<address> addresses { get; set; } } 

and connection string:

<?xml version="1.0" encoding="utf-8" ?> <configuration>     <connectionstrings>     <add name="addressbook" providername="system.data.sqlclient"            connectionstring="data source=mymachine;initial catalog=addressbook;          integrated security=true;multipleactiveresultsets=true;"/>     </connectionstrings> </configuration> 

so, database name "addressbook" , error happens when trying add contact object context. missing here?

now it's:

protected override void onmodelcreating(dbmodelbuilder modelbuilder) {     database.setinitializer<yourdbcontext>(null);     base.onmodelcreating(modelbuilder); } 

in yourdbcontext.cs file.