ASP.NET add migration 'composite primary key error' how to use fluent API
On EF core ..
Composite keys can only be configured using the Fluent API -conventions will never setup a composite key and you can not use DataAnnotations to configure one.
Here is the Fluent API version :
Note: This is just an example. Please adjust it according to your use case.
// (In the DbContext subclass)protected override void OnModelCreating(ModelBuilder modelBuilder){ modelBuilder.Entity<Attends>() .HasKey(c => new { c.FarmerSS, c. HotelID });}You can read more about it here : composite key