TPH继承问题 [英] TPH Inheritance problem
问题描述
我有以下情况：
DB-Table：
CREATE TABLE [base]。[AppointmentResource]
（
Id int Identity（1,1）NOT NULL，
IsDeleted bit，
DBTimestamp timestamp NOT NULL，
FKAppointmentId int NOT NULL，
CREATE TABLE [base].[AppointmentResource]
(
Id int Identity(1,1) NOT NULL,
IsDeleted bit,
DBTimestamp timestamp NOT NULL,
FKAppointmentId int NOT NULL,
FKLocationId int NULL，
FKProductId int NULL，
FKLogOnUserId int NULL，
FKPatientId int NULL
）;
FKLocationId int NULL,
FKProductId int NULL,
FKLogOnUserId int NULL,
FKPatientId int NULL
);
我创建了4个实体，其基类是AppointmentResource，我将每个FK移动到其中一个（FKAppointmentId除外，它链接到约会本身）。所以我有4个新实体：AppLocation，AppProduct，AppLogOnUser和AppPatient。这些新实体没有字段，只有"导航属性"。各自的详细信息表。
I created 4 entities which's base-class is AppointmentResource and I moved each FK to one of them (except FKAppointmentId, which links to the appointment itself). So I have 4 new entities: AppLocation, AppProduct, AppLogOnUser and AppPatient. These new entities have no fields, just the "navigation property" to their respective detail-table.
设计人员不会验证模型并说明：
The designer won't validate the model and states:
错误1错误3022：从第1876行开始映射片段中的问题：必须映射具有'IsNull = false'条件的属性AppointmentResource.FKLocationId。
Error 1 Error 3022: Problem in Mapping Fragment starting at line 1876: Property AppointmentResource.FKLocationId with 'IsNull=false' condition must be mapped.
C：\DEV\TFS \Source1 \Synergy\DEV \ SERVER \ServicesHost \Synergy.edmx 1877 15 ServicesHost
错误2错误3022：从第1884行开始映射片段中的问题：必须映射具有'IsNull = false'条件的属性AppointmentResource.FKPatientId。
C:\DEV\TFS\Source1\Synergy\DEV\SERVER\ServicesHost\Synergy.edmx 1877 15 ServicesHost
Error 2 Error 3022: Problem in Mapping Fragment starting at line 1884: Property AppointmentResource.FKPatientId with 'IsNull=false' condition must be mapped.
C：\DEV \ TFS \Source1 \Synergy\DEV \ SERVER \ ServicesSost\Synergy.edmx 1885 15 ServicesHost
错误3错误3022：从第1891行开始映射片段中的问题：必须映射具有'IsNull = false'条件的属性AppointmentResource.FKProductId。
C:\DEV\TFS\Source1\Synergy\DEV\SERVER\ServicesHost\Synergy.edmx 1885 15 ServicesHost
Error 3 Error 3022: Problem in Mapping Fragment starting at line 1891: Property AppointmentResource.FKProductId with 'IsNull=false' condition must be mapped.
C：\DEV \\ TFS \Source1 \Synergy\DEV \ SERVER \ServicesHost \Synergy.edmx 1892 15 ServicesHost
错误4错误3022：从第1898行开始映射片段中的问题：属性AppointmentResource.FKLogOnUserId with'IsNull =必须映射false'条件。
C:\DEV\TFS\Source1\Synergy\DEV\SERVER\ServicesHost\Synergy.edmx 1892 15 ServicesHost
Error 4 Error 3022: Problem in Mapping Fragment starting at line 1898: Property AppointmentResource.FKLogOnUserId with 'IsNull=false' condition must be mapped.
C：\DEV \ TFS \Source1 \Synergy\DEV \ SERVER \ Serviceshost \Synergy.edmx 1899 15 ServicesHost
C:\DEV\TFS\Source1\Synergy\DEV\SERVER\ServicesHost\Synergy.edmx 1899 15 ServicesHost
courese它们没有被映射，因为映射是在关系中定义的，而不是表格！
Of courese they aren't mapped, because the mapping is defined in the relation, not the table!
任何人都有建议如何绕过这个错误？
Anyone have a suggestion of how to circumvent this error?
推荐答案
根据博客我发现这是一个错误？！ http://msmvps.com/blogs/matthieu/archive/2008/08/23 /tph-limitation-which-should-disappear-with-v2.aspx
请告诉我有一个解决方法！我无法相信EF团队错过了这一点......
Please tell me there is a workaround! I can't believe this was missed by the EF-team...
这篇关于TPH继承问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
