sql - Local database changes not saved after SubmitChanges() -

i'm using local database store data. have file *.sdf load isolated storage, because want application work in offline mode, if user doesn't want, doesn't have update data.

this how datacontext like:

public class tablesdatacontext : datacontext {     // specify connection string static, used in main page , app.xaml.     public static string dbconnectionstring = "data source=isostore:/mydatabase.sdf";      // pass connection string base class.     public tablesdatacontext(string connectionstring)         : base(connectionstring)     { }      // specify single table items.     public table<customeritem> customerstable;     public table<productitem> productstable; } 

here in app.xaml.cs if needed create database:

// create database if not exist. using (tablesdatacontext db = new tablesdatacontext(tablesdatacontext.dbconnectionstring)) {     if (db.databaseexists() == false)     {         //create database         db.createdatabase();     } } datacontext = new userdatacontext(); 

and settingspage in update needed information:

public partial class settingspage : phoneapplicationpage {      // data context local database     private tablesdatacontext tablesdb;      // define observable collection property controls can bind to.     private observablecollection<customeritem> _customerstable;     public observablecollection<customeritem> customerstable     {                 {             return _customerstable;         }         set         {             if (_customerstable != value)             {                 _customerstable = value;                 notifypropertychanged("customerstable");             }         }     }      // define observable collection property controls can bind to.     private observablecollection<productitem> _producttable;     public observablecollection<productitem> producttable     {                 {             return _producttable;         }         set         {             if (_producttable != value)             {                 _producttable = value;                 notifypropertychanged("producttable");             }         }     }      public void addingcustomerstodatabase(list<customerjson> customerslist)     {          // define query gather of to-do items.         var customerstablesindb = customeritem todo in tablesdb.customerstable                                   select todo;          // execute query , place results collection.         customerstable = new observablecollection<customeritem>(customerstablesindb);          tablesdb.customerstable.deleteallonsubmit(customerstable);         tablesdb.submitchanges();          foreach (customerjson customer in customerslist)         {             // create new to-do item based on text box.             customeritem newcustomer = new customeritem             {                 // filling customer data json object             };              // add to-do item observable collection.             customerstable.add(newcustomer);              // add to-do item local database.             tablesdb.customerstable.insertonsubmit(newcustomer);             tablesdb.submitchanges();         }     }      public void addingproductstodatabase(list<productjson> productslist)     {            // same things in previouse method products objects     }      private void load_click(object sender, routedeventargs e)     {         addingcustomerstodatabase(customerslist);         addingproductstodatabase(productslist);     } } 

after updating information i'm sure data up-to-date, until close application. if reopen application, still has old data. if understand correctly shouldn't saved in *.sdf file? btw, i'm using linq.

edit:

i managed check , found out right after json parsing, database updated (*.sdf file filled new data), when close , open application again (not build, reopen on emulator), again has old data.

please try following

1. verify if json data updated

2. try using "addobject" instead of "insertonsubmit" below

   tablesdb.customerstable.addobject(newcustomer);