使用EF CPT5进行域建模和映射
我正在尝试制作一张包含照片集的相册。每个专辑都有一组照片和一张拇指照片。这就是我所拥有的，但EF似乎并不喜欢它。我正在使用EF CPT5
模特：
public class Album : IEntity {
private DateTime _dateCreated;
public Album() {
_dateCreated = SystemTime.Now();
Photos = new List<Photo>();
}
public long Id { get; set; }
public string Name { get; set; }
public string Location { get; set; }
public DateTime DateCreated { get { return _dateCreated; } set { _dateCreated = value; } }
public virtual Site Site { get; set; }
public virtual Photo Thumbnail { get; set; }
public long ThumbnailId { get; set; }
public virtual ICollection<Photo> Photos { get; set; }
}
public class Photo : IEntity {
public Photo() {
_dateCreated = SystemTime.Now();
}
private DateTime _dateCreated;
public long Id { get; set; }
public string Caption { get; set; }
public string FileName { get; set; }
public DateTime DateCreated<br/>{ get { return _dateCreated; } set { _dateCreated = value; } }
public long AlbymId { get; set; }
public virtual Album Album { get; set; }
}
映射代码：
public class AlbumMap : EntityTypeConfiguration<Album> {
public AlbumMap() {
HasRequired(x => x.Thumbnail).WithMany().HasForeignKey(a => a.ThumbnailId).WillCascadeOnDelete(false);
Property(x => x.Location).IsVariableLength().HasMaxLength(80);
Property(x => x.Name).IsVariableLength().HasMaxLength(80).IsRequired();
}
}
public class PhotoMap : EntityTypeConfiguration<Photo> {
public PhotoMap() {
HasRequired(p => p.Album).WithMany(a => a.Photos).HasForeignKey(p => p.AlbymId);
Property(x => x.FileName).IsVariableLength().HasMaxLength(255).IsRequired();
Property(x => x.Caption).IsVariableLength().HasMaxLength(255);
Property(x => x.DateCreated);
ToTable("SiteAlbumPhotos");
}
}
上下文
public class Database : ObjectContext {
public Database(EntityConnection connection) : base(connection) {
ContextOptions.LazyLoadingEnabled = true;
ContextOptions.ProxyCreationEnabled = true;
}
private IObjectSet<User> _users;
private IObjectSet<Site> _sites;
private IObjectSet<SiteDonation> _donations;
private IObjectSet<SiteAnnouncement> _siteAnnouncements;
private IObjectSet<SiteData> _siteData;
private IObjectSet<SiteLink> _siteLinks;
private IObjectSet<SitePost> _sitePosts;
private IObjectSet<Theme> _theme;
private IObjectSet<Album> _siteAlbums;
private IObjectSet<Photo> _siteAlbumPhotos;
private IObjectSet<CommunityPost> _communityPosts;
private IObjectSet<CommunityComment> _communityComments;
public IObjectSet<User> Users {
get{ return _users ?? (_users = ObjectSet<User>()); }
}
public IObjectSet<Album> SiteAlbums {
get { return _siteAlbums ?? (_siteAlbums = ObjectSet<Album>()); }
}
public IObjectSet<Photo> SiteAlbumsPhotos {
get { return _siteAlbumPhotos ?? (_siteAlbumPhotos = ObjectSet<Photo>()); }
}
public IObjectSet<Site> Sites {
get{ return _sites ?? (_sites = ObjectSet<Site>()); }
}
public IObjectSet<SiteDonation> SiteDonations {
get { return _donations ?? (_donations = ObjectSet<SiteDonation>()); }
}
public IObjectSet<SiteAnnouncement> SiteAnnouncements {
get { return _siteAnnouncements ?? (_siteAnnouncements = ObjectSet<SiteAnnouncement>()); }
}
public IObjectSet<SiteData> SiteData {
get { return _siteData ?? (_siteData = ObjectSet<SiteData>()); }
}
public IObjectSet<SiteLink> SiteLinks {
get { return _siteLinks ?? (_siteLinks = ObjectSet<SiteLink>()); }
}
public IObjectSet<SitePost> SitePosts {
get { return _sitePosts ?? (_sitePosts = ObjectSet<SitePost>()); }
}
public IObjectSet<Theme> Themes {
get { return _theme ?? (_theme = ObjectSet<Theme>()); }
}
public IObjectSet<CommunityPost> CommunityPosts {
get { return _communityPosts ?? (_communityPosts = ObjectSet<CommunityPost>()); }
}
public IObjectSet<CommunityComment> CommunityComments {
get { return _communityComments ?? (_communityComments = ObjectSet<CommunityComment>()); }
}
public virtual IObjectSet<T> ObjectSet<T>() where T : class, IEntity {
return CreateObjectSet<T>();
}
public virtual void Commit() {
SaveChanges();
}
}
DatabaseFactory
public class DatabaseFactory : Disposable, IDatabaseFactory
{
private static readonly ModelBuilder builder = CreateBuilder();
private readonly DbProviderFactory _providerFactory;
private readonly string _connectionString;
private Database _database;
//
public DatabaseFactory(DbProviderFactory providerFactory, string connectionString)
{
Check.Argument.IsNotNull(providerFactory, "providerFactory");
Check.Argument.IsNotNullOrEmpty(connectionString, "connectionString");
_providerFactory = providerFactory;
_connectionString = connectionString;
}
//
public Database Get()
{
if(_database == null)
{
var connection = _providerFactory.CreateConnection();
connection.ConnectionString = _connectionString;
//_database = builder.CreateModel(connection); LEG 1 CPT 3
//var ctx = dbModel.CreateObjectContext<ObjectContext>(_connectionString); LEG 1 CPT 3
//var modelBuilder = builder.CreateModel(); LEG 2 CPT 4
//_database = modelBuilder.CreateObjectContext<Database>(connection); LEG 2 CPT 4
//_database = modelBuilder.CreateObjectContext<Database>(connection); LEG 2 CPT 4
var modelBuilder = builder.Build(connection);
var dbModel = new DbModel(modelBuilder);
_database = dbModel.CreateObjectContext<Database>(connection);
}
return _database;
}
//
protected override void DisposeCore()
{
if (_database != null)
{
_database.Dispose();
}
}
//
private static ModelBuilder CreateBuilder()
{
//ContextBuilder<Database> contextBuilder = new ContextBuilder<Database>();
var contextBuilder = new ModelBuilder();
//IEnumerable<Type> configurationTypes = typeof(DatabaseFactory)
// .Assembly
// .GetTypes()
// .Where(type => type.IsPublic && type.IsClass && !type.IsAbstract && !type.IsGenericType && typeof(StructuralTypeConfiguration).IsAssignableFrom(type) && (type.GetConstructor(Type.EmptyTypes) != null));
//foreach (StructuralTypeConfiguration configuration in configurationTypes.Select(type => (StructuralTypeConfiguration)Activator.CreateInstance(type)))
//{
// contextBuilder.Configurations.Add(configuration);
//}
contextBuilder.Configurations.Add(new CommunityCommentMap());
contextBuilder.Configurations.Add(new CommunityPostMap());
contextBuilder.Configurations.Add(new SiteAlbumMap());
contextBuilder.Configurations.Add(new SiteAlbumPhotoMap());
contextBuilder.Configurations.Add(new SiteAnnouncementMap());
contextBuilder.Configurations.Add(new SiteDataMap());
contextBuilder.Configurations.Add(new SiteDonationMap());
contextBuilder.Configurations.Add(new SiteLinkMap());
contextBuilder.Configurations.Add(new SiteMap());
contextBuilder.Configurations.Add(new SitePostMap());
contextBuilder.Configurations.Add(new ThemeMap());
contextBuilder.Configurations.Add(new UserMap());
return contextBuilder;
}
}
我是否正确建模和映射？我需要能够在不指定缩略图的情况下创建新的相册。截至目前，这一切都有效，直到我尝试添加缩略图，然后我收到此错误：
System.Data.UpdateException：无法确定相关操作的有效排序。由于外键约束，模型要求或存储生成的值，可能存在依赖关系。
在System.Data.Mapping.Update.Internal.UpdateTranslator.DependencyOrderingError（IEnumerable`1余数） 在System.Data.Mapping.Update.Internal.UpdateTranslator.ProduceCommands（） 在System.Data.Mapping.Update.Internal.UpdateTranslator.Update（IEntityStateManager stateManager，IEntityAdapter adapter） 在System.Data.Objects.ObjectContext.SaveChanges（SaveOptions选项） 在Database.cs中的PostHope.Infrastructure.DataAccess.Database.Commit（）中：第74行 在BuildDatabase.cs中的PostHope.Infrastructure.DataAccess.IntegrationTests.BuildDatabase.Add_test_data_to_database（）：第252行
任何帮助都会很棒！
1 个答案:
答案 0 :(得分：2)
我们通过EF CTP4 here解决了这个问题。现在这里是EF CTP5的更新，今天早些时候已经released。
public class Photo
{
public long PhotoId { get; set; }
[MaxLength(255)]
public string Caption { get; set; }
[MaxLength(255)][Required]
public string FileName { get; set; }
public DateTime DateCreated { get; set; }
public long AlbumId { get; set; }
public virtual Album Album { get; set; }
}
[Table("SiteAlbumPhotos")]
public class Album
{
public long AlbumId { get; set; }
[MaxLength(80)][Required]
public string Name { get; set; }
[MaxLength(80)]
public string Location { get; set; }
public DateTime DateCreated { get; set; }
public long ThumbnailId { get; set; }
public virtual Photo Thumbnail { get; set; }
public virtual ICollection<Photo> Photos { get; set; }
}
public class PhotoMap : EntityTypeConfiguration<Photo> {
public PhotoMap() {
HasRequired(p => p.Album).WithMany(a => a.Photos)
.HasForeignKey(p => p.AlbumId);
}
}
public class AlbumMap : EntityTypeConfiguration<Album> {
public AlbumMap() {
HasRequired(a => a.Thumbnail).WithMany()
.HasForeignKey(a => a.ThumbnailId)
.WillCascadeOnDelete(false);
}
}
public class MyContext : DbContext {
public DbSet<Photo> Photos { get; set; }
public DbSet<Album> Albums { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder) {
modelBuilder.Configurations.Add<Photo>(new PhotoMap());
modelBuilder.Configurations.Add<Album>(new AlbumMap());
}
}
此数据库架构的结果如下：
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