Mapping composite types from postgresql to ef core

Question

I defined the following composite type in my postgre db:

CREATE TYPE foobar AS
(
   foo NUMERIC,
   bar NUMERIC
);

I have created a struct with the same properties:

public struct FooBar
{
   public decimal Foo { get; set; }
   public decimal Bar { get; set; }
}

And now I would like to use FooBar as such in an entity:

public class FooyaEntity
{
   public Guid Id { get; set; }
   public string Name { get; set; }
   public FooBar FooBar { get; set; }
}

How would I configure ef core to map these properly? Currently when trying to add something it will yield the following error:

System.InvalidOperationException: The property 'Test.FooBar' could not be mapped, because it is of type 'FooBar' which is not a supported primitive type or a valid entity type. Either explicitly map this property, or ignore it using the '[NotMapped]' attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.

Also the documentation for npgsql shows working examples without ef core.

Answer 1

Mapping to PostgreSQL composite types isn't yet supported, this is tracked by this issue. Anyone interested, please go upvote it!