Entity Framework - not using linked table id in insert query - sql

Question

I have 2 tables, Foo and Bar, Foo has a link to a Bar record
public class Foo
{
public int Id { get; set; }
public Bar SomeBar{ get; set; }
}
public class Bar
{
public int? Id { get; set; }
...
}
the SQL table (with the FK constraint between the two tables):
CREATE TABLE [dbo].[Foo] (
[Id] INT IDENTITY (1, 1) NOT NULL PRIMARY KEY,
[SomeBarId] INT NOT NULL,
CONSTRAINT [FK_Foo_Bar] FOREIGN KEY ([SomeBarId]) REFERENCES [Bar]([Id]),
);
when I save the table, Entity does not use SomeBarId in the query, producing an error, while I have set a FK constraint between the two tables
Cannot insert the value NULL into column 'SomeBarId ', table 'dbo.foo'; column does not allow nulls. INSERT fails.
how do I tell entity to use the field SomeBarId when doing the insert ?
var someBar = await _context.Bars.FindAsync(1); // fetch a Bar record
foo.SomeBar = someBar; // linking the objects
_context.Foo.Add(foo);
await _context.SaveChangesAsync();
I expect EF to get someBar.Id and use it in the query when inserting Foo in DB
thanks for the time you'll spend helping me on this

Answer 1

Try adding ForeignKey attribute in class Foo and remove the nullable Id in Bar
public class Foo
{
[ForeignKey("Bar")]
public int Id { get; set; }
public Bar SomeBar{ get; set; }
}
public class Bar
{
public int Id { get; set; }
...
}