如何更新具有一对一关系的实体？

Question

我有如下实体：

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; }
}

我的服务请求是：

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

我要根据要求更新所有电脑

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),
                                         } 
                        });

如果Request.DeviceGuid不为空，我更新属于该设备的所有计算机；如果 Request.SerialNo 不为空，我只更新计算机。其中一个在列表的每一项中总是为空。

但是我收到一个错误

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

SQL确实没有关系。

还有一个选项我可以成功更新，但我不确定这是一个有效的方法：

var computerList = computers.ToList();

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

那么我怎样才能最有效地处理这种情况呢？

Answer 1

NHibernate 中的 LINQ 更新不支持关系实体的更新。您可以尝试使用子查询来查找您需要更新的所有实体。类似于：

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),
        }
);

如何更新具有一对一关系的实体？

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

c#

linq

nhibernate

iqueryable

linq-to-nhibernate