WCF RIA entity Update from Lightswitch for Many to many relationship

Question

I have two entities which have many to many relationship. I need to create a screen to update data from both the tables simultaneously using a screen. So I used First as a sql database entity in Lightswitch second is RIA service Entity(Which is junction table).
both tables are editable in a same screen but when I click on Save button,
System call to
[Query(IsDefault = true)]public IEnumerable<EquipmentJob> SelectFakeJobs()  
method instead of calling
[Query]public IEnumerable<EquipmentJob> SelectJobs(long? ID).
I am using the Ria table as a query in my screen and setting the parameter as a table1.SelectedItem.ID.  But after click on save it does not call to parameterized
method to get data. I have already implemented the 'Saving' method.  It gives following exception.
Only changes to a single data service can be saved.  To save changes to multiple data services, implement the "Saving" method.
Data conflict. another user has deleted the record.
I followed following link to setup the Many to Many relationship update in LightSwitch
http://powerbala.com/many-to-many-control-for-microsoft-lightswitch/

Answer 1

Only changes to a single data service can be saved.  To save changes to multiple data services, implement the "Saving" method.
 This issue is discussed before, generally you need implement the <ScreenName>_InitializeDataWorkspace method and add the data services that you'd like to save to the saveChangesTo list.
https://social.msdn.microsoft.com/Forums/en-US/238e5e91-8598-42f9-817d-12b6f5b980a1/having-a-problem-saving-getting-error?forum=lightswitch