C# 保存更改时设置默认值
所有我的实体都扩展了具有以下(相关)属性的C# 保存更改时设置默认值,c#,entity-framework-core,ef-fluent-api,.net-core-2.2,C#,Entity Framework Core,Ef Fluent Api,.net Core 2.2,所有我的实体都扩展了具有以下(相关)属性的BaseEntity: namespace Sppd.TeamTuner.Core.Domain.Entities { public abstract class BaseEntity { /// <summary> /// Unique identifier identifying a single instance of an entity. /// </sum
BaseEntity
:
namespace Sppd.TeamTuner.Core.Domain.Entities
{
public abstract class BaseEntity
{
/// <summary>
/// Unique identifier identifying a single instance of an entity.
/// </summary>
public Guid Id { get; set; }
/// <summary>
/// Specifies when the entity instance has been created.
/// </summary>
public DateTime CreatedOnUtc { get; set; }
/// <summary>
/// Specifies by whom the entity instance has been created.
/// </summary>
public Guid CreatedById { get; set; }
/// <summary>
/// Specifies when the entity instance has been last updated.
/// </summary>
public DateTime ModifiedOnUtc { get; set; }
/// <summary>
/// Specifies by whom the entity instance has been last modified.
/// </summary>
public Guid ModifiedById { get; set; }
protected BaseEntity()
{
Id = Guid.NewGuid();
}
}
}
这个值生成器
:
internal class CurrentUserIdValueGenerator : ValueGenerator<Guid>
{
public override bool GeneratesTemporaryValues => false;
public override Guid Next(EntityEntry entry)
{
return GetCurrentUser(entry).Id;
}
private static ITeamTunerUser GetCurrentUser(EntityEntry entry)
{
var userProvider = entry.Context.GetService<ITeamTunerUserProvider>();
if (userProvider.CurrentUser != null)
{
return userProvider.CurrentUser;
}
if (entry.Entity is ITeamTunerUser user)
{
// Special case for user creation: The user creates himself and thus doesn't exist yet. Use him as the current user.
return user;
}
throw new BusinessException("CurrentUser not defined");
}
}
检查ChangeTracker
的内容时,所有实体都设置了ModifiedById
:
旁注:ToList()
是必需的,否则无法正确枚举
除了id包含我期望的值之外,ModifiedById
属性不可为null,因此不应为null(它可能包含default(Guid)
)
知道发生了什么吗
[编辑]要添加的代码:
播种机:
internal class CardTypeDbSeeder : IDbSeeder
{
private readonly IRepository<CardType> _cardTypeRepository;
public CardTypeDbSeeder(IRepository<CardType> cardTypeRepository)
{
_cardTypeRepository = cardTypeRepository;
}
public int Priority => SeederConstants.Priority.BASE_DATA;
public void Seed()
{
_cardTypeRepository.Add(new CardType
{
Id = Guid.Parse(TestingConstants.CardType.ASSASSIN_ID),
Name = "Assassin"
});
}
[...]
}
内部类CardTypeDbSeeder:IDbSeeder
{
私有只读IRepository\u cardTypeRepository;
公共CardTypedBeeder(IRepository cardTypeRepository)
{
_cardTypeRepository=cardTypeRepository;
}
public int Priority=>SeederConstants.Priority.BASE_数据;
公开无效种子()
{
_cardTypeRepository.Add(新的CardType
{
Id=Guid.Parse(TestingConstants.CardType.刺客Id),
Name=“刺客”
});
}
[...]
}
存储库:
namespace Sppd.TeamTuner.Infrastructure.DataAccess.EF.Repositories
{
internal class Repository<TEntity> : IRepository<TEntity>
where TEntity : BaseEntity
{
protected DbSet<TEntity> Set => Context.Set<TEntity>();
protected TeamTunerContext Context { get; }
protected virtual Func<IQueryable<TEntity>, IQueryable<TEntity>> Includes { get; } = null;
public Repository(TeamTunerContext context)
{
Context = context;
}
public async Task<TEntity> GetAsync(Guid entityId)
{
TEntity entity;
try
{
entity = await GetQueryWithIncludes().SingleAsync(e => e.Id == entityId);
}
catch (InvalidOperationException)
{
throw new EntityNotFoundException(typeof(TEntity), entityId.ToString());
}
return entity;
}
public async Task<IEnumerable<TEntity>> GetAllAsync()
{
return await GetQueryWithIncludes().ToListAsync();
}
public void Delete(Guid entityId)
{
var entityToDelete = GetAsync(entityId);
entityToDelete.Wait();
Set.Remove(entityToDelete.Result);
}
public void Add(TEntity entity)
{
Set.Add(entity);
}
public void Update(TEntity entity)
{
Set.Update(entity);
}
protected IQueryable<TEntity> GetQueryWithIncludes()
{
return Includes == null
? Set
: Includes(Set);
}
}
}
名称空间Sppd.TeamTuner.Infrastructure.DataAccess.EF.Repositories
{
内部类存储库:IRepository
其中tenty:BaseEntity
{
受保护的DbSet Set=>Context.Set();
受保护的TeamTunerContext上下文{get;}
受保护的虚拟函数包括{get;}=null;
公共存储库(TeamTunerContext上下文)
{
上下文=上下文;
}
公共异步任务GetAsync(Guid entityId)
{
触角实体;
尝试
{
entity=await GetQueryWithIncludes().SingleAsync(e=>e.Id==entityId);
}
捕获(无效操作异常)
{
抛出新的EntityNotFoundException(typeof(tenty),entityId.ToString());
}
返回实体;
}
公共异步任务GetAllAsync()
{
return wait wait getquerywhincludes().toListSync();
}
公共无效删除(Guid entityId)
{
var entityToDelete=GetAsync(entityId);
entityToDelete.Wait();
Set.Remove(entityToDelete.Result);
}
公共无效添加(TEntity实体)
{
设置、添加(实体);
}
公共无效更新(TEntity实体)
{
设置、更新(实体);
}
受保护的IQueryable GetQueryWithIncludes()
{
返回Includes==null
设置
:包括(套);
}
}
}
提交更改:
if (isNewDatabase)
{
s_logger.LogDebug($"New database created. Seed data for SeedMode={databaseConfig.SeedMode}");
foreach (var seeder in scope.ServiceProvider.GetServices<IDbSeeder>().OrderBy(seeder => seeder.Priority))
{
seeder.Seed();
s_logger.LogDebug($"Seeded {seeder.GetType().Name}");
}
// The changes are usually being saved by a unit of work. Here, while starting the application, we will do it on the context itself.
context.SaveChanges();
}
if(isNewDatabase)
{
s_logger.LogDebug($“为SeedMode创建了新数据库。种子数据={databaseConfig.SeedMode}”);
foreach(scope.ServiceProvider.GetServices().OrderBy中的var seeder(seeder=>seeder.Priority))
{
播种机;
LogDebug($“seedd{seeder.GetType().Name}”);
}
//更改通常由一个工作单元保存。在这里,当启动应用程序时,我们将在上下文本身上进行保存。
SaveChanges();
}
正如评论中所讨论的,在GitHub问题中进行了大量的浏览,结果是不可能使用值生成器来实现这一点。我通过在Datacontext.SaveChanges
的重写中实现一个PrepareSaveChanges()
来解决这个问题,它调用以下代码:
private void SetModifierMetadataProperties(EntityEntry<BaseEntity> entry, DateTime saveDate)
{
var entity = entry.Entity;
var currentUserId = GetCurrentUser(entry).Id;
if (entity.IsDeleted)
{
entity.DeletedById = currentUserId;
entity.DeletedOnUtc = saveDate;
return;
}
if (entry.State == EntityState.Added)
{
entity.CreatedById = currentUserId;
entity.CreatedOnUtc = saveDate;
}
entity.ModifiedById = currentUserId;
entity.ModifiedOnUtc = saveDate;
}
private void SetModifierMetadataProperties(EntityEntry,DateTime saveDate)
{
var实体=条目。实体;
var currentUserId=GetCurrentUser(条目).Id;
if(实体已删除)
{
entity.DeletedById=currentUserId;
entity.DeletedOnUtc=保存日期;
返回;
}
if(entry.State==EntityState.Added)
{
entity.CreatedById=currentUserId;
entity.CreatedOnUtc=保存日期;
}
entity.ModifiedById=currentUserId;
entity.ModifiedOnUtc=保存日期;
}
对于完整的实现,请按照注释中讨论的覆盖的执行路径以及GitHub问题中的大量浏览,结果表明,不可能使用值生成器来实现此功能。我通过在
Datacontext.SaveChanges
的重写中实现一个PrepareSaveChanges()
来解决这个问题,它调用以下代码:
private void SetModifierMetadataProperties(EntityEntry<BaseEntity> entry, DateTime saveDate)
{
var entity = entry.Entity;
var currentUserId = GetCurrentUser(entry).Id;
if (entity.IsDeleted)
{
entity.DeletedById = currentUserId;
entity.DeletedOnUtc = saveDate;
return;
}
if (entry.State == EntityState.Added)
{
entity.CreatedById = currentUserId;
entity.CreatedOnUtc = saveDate;
}
entity.ModifiedById = currentUserId;
entity.ModifiedOnUtc = saveDate;
}
private void SetModifierMetadataProperties(EntityEntry,DateTime saveDate)
{
var实体=条目。实体;
var currentUserId=GetCurrentUser(条目).Id;
if(实体已删除)
{
entity.DeletedById=currentUserId;
entity.DeletedOnUtc=保存日期;
返回;
}
if(entry.State==EntityState.Added)
{
entity.CreatedById=currentUserId;
entity.CreatedOnUtc=保存日期;
}
entity.ModifiedById=currentUserId;
entity.ModifiedOnUtc=保存日期;
}
对于完整的实现,请按照覆盖的执行路径执行您是否在Insert或Update?Insert中收到错误。当我在创建DBTry之后对数据进行种子设定时,会发生这种情况,手动设置ModifiedById的值,然后查看错误是否移动到下一个属性。如果不这样做,则可以正常工作。我使用了另一种方法,使用EntityMetadataProviders在PrepareSaveChanges中设置这些值,这不会导致任何问题。但这样做看起来更性感。由于这个错误对我来说没有意义,我想了解到底发生了什么,并希望它能以这种方式工作
private void SetModifierMetadataProperties(EntityEntry<BaseEntity> entry, DateTime saveDate)
{
var entity = entry.Entity;
var currentUserId = GetCurrentUser(entry).Id;
if (entity.IsDeleted)
{
entity.DeletedById = currentUserId;
entity.DeletedOnUtc = saveDate;
return;
}
if (entry.State == EntityState.Added)
{
entity.CreatedById = currentUserId;
entity.CreatedOnUtc = saveDate;
}
entity.ModifiedById = currentUserId;
entity.ModifiedOnUtc = saveDate;
}