How to update Entity that have one-to-one relation?-CodePudding

I have entities as follows:

public class Device
{
    public long Guid { get; set; }
    public List<Computer> Computers { get; set; }
    public string ShopName { get; set; }
}

public class Computer
{
    public long Guid { get; set; }
    public long SerialNo { get; set; }
    public Device Device { get; set; }
    public Condition Condition { get; set; }
}

public class Condition
{
    public long Guid { get; set; }
    public bool hasDamage { get; set; }
    public bool IsSecondHand { get; set; }
    public Computer Computer { get; set; }
}

The request of my service is :

public class Request
{
    public long? DeviceGuid {get; set;}
    public long? SerialNo {get; set;}
    public bool? IsSecondHand {get; set;}
}

I want to update all the computers according to request

foreach (var requestItem in RequestList)
{
    var ComputerPredicate = PredicateBuilder.True<Computer>()
                                            .And(x => x.SerialNo== requestItem.SerialNo)
                                            .And(x => x.Device.Guid== requestItem.DeviceGuid);

    var computers = from computers in ISession.Query<Computer>()
                                              .Where(ComputerPredicate)
                    select computers;

    computers.Update(u => new Computer()
                        {
                            Condition = new Condition()
                                        {
                                            IsSecondHand = requestItem.IsSecondHand.GetValueOrDefault(false),
                                         } 
                        });

If Request.DeviceGuid is not null, I update the all computers belong to that device; if Request.SerialNo is not null I update only the computer. One of them always empty in each item of the list.

But I am getting an error

NHibernate.Exceptions.GenericADOException: 'could not execute update query[SQL: update COMPUTER set Condition.IsSecondHand=? where and serialno=?]'
PostgresException: 42703: column "condition" of relation "computer" does not exist

There is no relation in the SQL indeed.

There is another option that I can update successfully but I am not sure this is an effective way to do it:

var computerList = computers.ToList();

foreach (var computer in computerList)
{
    computer.Condition.IsSecondHand = requestItem.IsSecondHand.GetValueOrDefault(false);
    ISession.Save(computer)
}

So how can I handle this situation in most efficient way?

CodePudding user response：

Updates on relation entities are not supported by LINQ update in NHibernate. You can try to use subquery to find all entities you need to update. Something like:

var entitiesToUpdateSubQuery = session.Query<Computer>()
.Where(ComputerPredicate)
.Select(x => x.Condition); //<- Select entity  you need to update

session.Query<Condition>() //<- Write update query directly on entity you need to update
.Where(c => entitiesToUpdateSubQuery.Contains(c)) 
.Update(c => 
    new Condition()
        {
            IsSecondHand = requestItem.IsSecondHand.GetValueOrDefault(false),
        }
);