我正在使用 Entity Framework 4.3 代码优先和手动迁移。我正在尝试映射使用两个自定义鉴别器字段的 TPH(按层次结构表)设置。一个用于鉴别器本身,另一个用于软删除(很像 NH 类映射中的“where”选项)。完全相同的设置在另一个在 EF 4.2 上运行的项目中工作得很好。
尝试使用 NuGet 控制台中的“add-migration”命令添加迁移时出现错误。我已经尝试了定义表名的所有组合 - 类上的属性、“OnModelCreating”方法、EntityTypeConfiguration 类等。我以前不涉及复杂层次结构映射的迁移工作得很好。
EF 4.3 中是否有一些我偶然发现的重大变化?
编码:
//---- Domain classes ---------------------
public abstract class ParentClass
{
public string ParentString { get; set; }
}
public class Foo : ParentClass
{
public string FooString { get; set; }
}
public class Bar : ParentClass
{
public string BarString { get; set; }
}
//---- Mapping configuration --------------
public class ParentConfiguration : EntityTypeConfiguration<ParentClass>
{
public ParentConfiguration()
{
Map<Foo>(m =>
{
m.Requires("IsActive").HasValue(1);
m.Requires("Type").HasValue("Foo");
})
.ToTable("Parent");
Map<Bar>(m =>
{
m.Requires("IsActive").HasValue(1);
m.Requires("Type").HasValue("Bar");
})
.ToTable("Parent");
}
}
//---- Context ----------------------------
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new ParentConfiguration());
}
错误:
System.InvalidOperationException: The type 'Foo' has already been mapped to table 'Parent'. Specify all mapping aspects of a table in a single Map call.
at System.Data.Entity.ModelConfiguration.Configuration.Types.EntityTypeConfiguration.AddMappingConfiguration(EntityMappingConfiguration mappingConfiguration)
at System.Data.Entity.ModelConfiguration.Configuration.ModelConfiguration.ReassignSubtypeMappings()
at System.Data.Entity.DbModelBuilder.Build(DbProviderManifest providerManifest, DbProviderInfo providerInfo)
at System.Data.Entity.DbModelBuilder.Build(DbConnection providerConnection)
at System.Data.Entity.Infrastructure.EdmxWriter.WriteEdmx(DbContext context, XmlWriter writer)
at System.Data.Entity.Migrations.Extensions.DbContextExtensions.<>c__DisplayClass1.<GetModel>b__0(XmlWriter w)
at System.Data.Entity.Migrations.Extensions.DbContextExtensions.GetModel(Action`1 writeXml)
at System.Data.Entity.Migrations.Extensions.DbContextExtensions.GetModel(DbContext context)
at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration, DbContext usersContext)
at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration)
at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.GetMigrator()
at System.Data.Entity.Migrations.Design.ToolingFacade.GetPendingMigrationsRunner.RunCore()
at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.Run()
米克尔