Question

I m 采用一种定制的方法,追踪单个经修改的、与一层不相连的实体类别。我从中摘取。

Programming Entity Framework: DbContext by Julia Lerman and Rowan Miller (O’Reilly). Copyright 2012 Julia Lerman and Rowan Miller, 978-1-449-31296-1.

该守则是:

public void ApplyChanges<TEntity>(TEntity root) where TEntity : class, IObjectWithState {
        // bind the entity back into the context
        dbContext.Set<TEntity>().Add(root);
        // throw exception if entity does not implement IObjectWithState
        CheckForEntitiesWithoutStateInterface(dbContext);

        foreach (var entry in dbContext.ChangeTracker.Entries<IObjectWithState>()) {
            IObjectWithState stateInfo = entry.Entity;
            if (stateInfo.State == RecordState.Modified) {
                // revert the Modified state of the entity
                entry.State = EntityState.Unchanged;
                foreach (var property in stateInfo.ModifiedProperties) {
                    // mark only the desired fields as modified
                    entry.Property(property).IsModified = true;
                }
            } else {
                entry.State = ConvertState(stateInfo.State);
            }
        }
        dbContext.SaveChanges();
    }

这种方法的目的是让欧洲武装部队只了解预先界定的一组实体领域,并准备在下届“拯救儿童”呼吁中更新。这需要这样做,才能使实体在协会工作。 NET MVC 3 如下:

on initial page load: the Get action of the controller is loading the entity object and passing it as a parameter to the view.
The View generate controls for editing 2 of the fields of the entity, and holds the ID of the record in a hidden field.
When hitting [save] and posting the entity back to the controller all of the fields excepting the 3 preserved in the view comes with a null value. This is the default behavior of the MVC binding manager.

如果在数据库中不作改动,更新的查询当然会超越未绘制地图的田地,判决如下:

UPDATE non_mapped_field_1 = NULL, ..., mapped_field_1 =  mapped_value_1 , mapped_field_2 =  mapped_value_2 , ... non_mapped_field_n = NULL WHERE ID = mapped_field_3

这是试图逐个跟踪领域并仅更新那些有兴趣的领域的原因。在与ApplyChanges()交接习惯方法之前 i m 添加一意欲列入向综合国家通报的实地清单。修改财产清单,以便作如下陈述:

UPDATE mapped_field_1 =  mapped_value_1 , mapped_field_2 =  mapped_value_2  WHERE id = mapped_value_3

问题在于,在ApplyChanges修改的一个领域,即:

entry.Property(property).IsModified = true;

该系统正在扔下以下<><<> > 除外>:

{System.InvalidOperationException: Member  IsModified  cannot be called for property  NotifyCEDeadline  on entity of type  User  because the property is not part of the Entity Data Model.

at System.Data.Entity.Internal.InternalPropertyEntry.ValidateNotDetachedAndInModel(String method)

at System.Data.Entity.Internal.InternalPropertyEntry.set_IsModified(Boolean value)

at System.Data.Entity.Infrastructure.DbPropertyEntry.set_IsModified(Boolean value)

...

因此,问题是。绕过这种“EF”的验证,或者让人们了解这一系统财产的存在情况,即试图改变的不动产。

arch:

EF Code first (annotation + Fluent API)
Oracle .NET EF Data provider (ODAC)
Context is injected to a cutom business context with nInject.MVC => this is the reason i customized the ApplyChanges() method from

using (var context = new BreakAwayContext()){ context.Set().Add(root);

简单地呼吁已经初创的目录

dbContext.Set(Root)
甲骨质数据库是人工创建的,即没有EF的帮助,因此没有使用EF元数据表。

Thanks, Ivan.

Answer 1

然而,我无法找到任何资料,说明你为何需要物品中称为“变造”的瞬间财产,以及(或)你为什么需要向欧洲法院说明正在修改的不动产(欧经会赢得一定能够坚持这种财产)。

变造财产的价值应由模范人确定,如果该财产在任何方面被包括在内。

您在申请中仅能加入法典。变换法只能用入物过滤已知财产。 CurrentValues.PropertyNames,例如:

foreach (var property in stateInfo.ModifiedProperties) { 
    // mark only the desired fields as modified 
    if (entry.CurrentValues.PropertyNames.Contains(property)) {
        entry.Property(property).IsModified = true; 
    }
}

Update: Ivan, very sorry I did not understand the problem better when you posted it several months ago and that I did not follow up after your added these clarifying comments. I think I understand better now. That said, I think the code snippet that I offered can be part of the solution. From looking at the exception you are getting again, I understand now that the problem that EF is detecting is that NotifyCEDDealine is not a persistent property (i.e. it is not mapped in the Code First model to a column in the database). IsModified can only be used against mapped properties, therefore you have two options: you change the code of the implementation of IObjectWithState in your entities so that non-mapped properties are not recorded in ModifiedProperties, or you use my code snippet to prevent calling IsModified with those.

这样做的替代办法是使用主计长。 TryUpdate Model 仅对贵实体中经修改的财产进行标注。

希望这一帮助(尽管我理解是很晚)。

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