Entity Framework update entity and childs entities, Bulk Delete part 2

In the previous post I’ve explained how to perform a single update, but what I’ve to do If I need to update a master entity and related child?
As I’ve explained to update my model I use the 3rd method:
Attach the model and set EntityState.Modified
Now how can I update the child in a many to many relationship?
Usually I delete old children and then I reinsert the new ones.
To do this in EF I need the bulk delete but EF6 currently don’t support it!!!!
The only way available in EF6 without use ExecuteSQlCommand is DbSet.RemoveRange.
Unfortunately RemoveRange will perform a select on DB also without .ToList() call but it’s faster than delete each item loaded by the first query

The code above will work also in one to one relationship.

public void UpdateSymbol(Symbol model, IEnumerable<SymbolExtra> extra = null)
    // I attach the main entity without perform a select

    #region remove all associated extra, this works also with one to one relationship and not only with one to many relationship
    var qDelete = from a in this.SymbolExtras
    where a.IdSymbol == model.IdSymbol
    select a;
    // RemoveRange unfortunately will execute the select on DB!!! But EF6 don't currently support bulk remove or bulk update

    // If extra is not null I'll add the new children
    model.SymbolExtras = extra;
    // I sign the model modifyed
    this.Entry(model).State = EntityState.Modified;

Sample usage

    MyDAL.UpdateSymbol(m, e);

Informazioni su Andrea Regoli

Project Manager .Net Developer WPF WP7 Asp.Net c# javascript ajax SQL sharepoint
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