This is the Entity Framework engine issue:
http://stackoverflow.com/questions/2141 ... 59#2326859
http://stackoverflow.com/questions/4144 ... ork-4?lq=1
Here is a way of creating 1 : 0…1 association with Entity Developer:
1. Create a database schema:
Code: Select all
CREATE TABLE [dbo].[Student](
[Student_ID] [bigint] IDENTITY(1,1) NOT NULL,
[Name] [nvarchar](max) NOT NULL,
CONSTRAINT [PK_Student] PRIMARY KEY (Student_ID)
)
GO
CREATE TABLE [dbo].[StudentContact](
[StudentContact_ID] [bigint] IDENTITY(1,1) NOT NULL,
[ContactNumber] [nvarchar](max) NOT NULL,
[Student_ID] [bigint] NULL,
CONSTRAINT [PK_StudentContact] PRIMARY KEY (StudentContact_ID)
)
GO
ALTER TABLE [dbo].[StudentContact] WITH CHECK ADD CONSTRAINT [FK_StudentContact_Student] FOREIGN KEY([Student_ID])
REFERENCES [dbo].[Student] ([Student_ID])
GO
2. Add these tables to the Entity Framework Model using Create Model Wizard.
3. Delete the StudentID foreign key property from StudentContact entity in the Designer.
4. Right-click the association and select Mapping Details from the context menu.
5. In the Mapping Details window, click the Mapped Entity drop-down and select StudentContact.
6. Add a condition to StudentContact: the Student_ID column with the IsNotNull operator. Click OK.
7. Select the Association between Student and StudentContact.
8. In the Properties window for the association, in the property called “End2”, which currently has the value StudentContacts(*), change its Multiplicity property to 1 (One) using its drop-down list.
9. Validate the model by right-clicking the design surface and choosing Validate.
For the 1..1 association there is no need to set the "Student_ID IsNotNul" condition (steps 4 through 6) because the column itself is not nullable in this case.
JIC:
* enable
DbContext template in your model and set its Fluent Mapping property to True
* select diagram and set Metadata Artifact Processing = Do Not Generate Mapping Files in the properties of EntityContextModel
