Problems with updating records through Many-To-Many mappings - fluent-nhibernate

Question

I have a problem where I have a many-to-many mappings in my table structure creating headaches when trying to edit a simple record.
Example layout of where I am having problems:
Facilities Many-to-One Locations
Facilities One-to-Many Users
Users Many-to-Many Locations
Users One-to-Many PreviousPasswords
If I make a change to a Facilities record (Change the name field) I get the following error upon save:
collection [Users.PreviousPasswords] was not processed by flush()
Mapping looks like:
public FacilitiesMap()
{
Table("Facilities");
Id(x => x.ID);
Map(x => x.Name);
HasMany(x => x.Users).KeyColumn("FacilitiesID").Cascade.AllDeleteOrphan().Inverse();
HasMany(x => x.Locations).KeyColumn("FacilitiesID").Cascade.AllDeleteOrphan().Inverse();
}
public UsersMap()
{
Table("Users");
Id(x => x.ID);
Map(x => x.FirstName);
Map(x => x.LastName);
References(x => x.Facilities, "FacilitiesID").ForeignKey("ID");
HasMany(x => x.PreviousPasswords).KeyColumn("UsersID").Cascade.AllDeleteOrphan().Inverse();
HasManyToMany<Locations>(x => x.Locations)
.Schema("Members")
.Table("UsersToLocations")
.ParentKeyColumn("UsersID")
.ChildKeyColumn("LocationsID")
.LazyLoad()
.Cascade.SaveUpdate().Inverse();
}
public LocationsMap()
{
Table("Locations");
Id(x => x.ID);
Map(x => x.Name);
References(x => x.Facilities, "FacilitiesID").ForeignKey("ID");
HasMany(x => x.Patients).KeyColumn("LocationsID").Cascade.AllDeleteOrphan().Inverse();
HasManyToMany<Users>(x => x.Users)
.Schema("Members")
.Table("UsersToLocations")
.ParentKeyColumn("LocationsID")
.ChildKeyColumn("UsersID")
.Cascade.SaveUpdate();
}
public PreviousPasswordsMap()
{
Table("PreviousPasswords");
Id(x => x.ID);
Map(x => x.Password);
Map(x => x.DateTime);
References(x => x.Users, "UsersID").ForeignKey("ID");
}
The only way I can do a successful update to the Facilities record is if I use the following function to get the record before changing and saving it:
public Facilities GetFacility(int id)
{
return FluentSessionManager.GetSession()
.CreateCriteria<Facilities>()
.Add(Expression.Eq("ID", id))
.SetFetchMode("Users", FetchMode.Eager)
.SetFetchMode("Locations", FetchMode.Eager)
.UniqueResult<Facilities>();
}
The problem with this method is that where there are 10,000 users it takes a long time to process this query. Or even worse, if we have 100 location as well, then it takes around 2 minutes to get the one Facilities record to edit.
I am sure there is some kind of issue in the Mapping. Not sure how to fix or even where to start. Any help with this would be greatly appreciated.
Thanks in advance.

Answer 1

Do you really need all the users for the facility? When you only add users you can use
HasMany(x => x.Users).ExtraLazyLoad();
and to improve the query when really all subcollections are needed
public Facilities GetFacility(int id)
{
var session = FluentSessionManager.GetSession();
// ignore the result, we only want to cache the results in the session
session.CreateCriteria<Facilities>()
.Add(Expression.Eq("ID", id))
.SetFetchMode("Users", FetchMode.Eager)
.Future<Facilities>();
return session.CreateCriteria<Facilities>()
.Add(Expression.Eq("ID", id))
.SetFetchMode("Locations", FetchMode.Eager)
.FutureValue<Facilities>().Value;
}