Disable cascade delete on EF Core 2 globally

Question

I need to know about ways of disabling cascade delete in EF Core 2 globally. Any help is appricated.

In EF 6.x we used following code to disable cascade delete on both OneToMany and ManyToMany realtions:

builder.Conventions.Remove<OneToManyCascadeDeleteConvention>(); builder.Conventions.Remove<ManyToManyCascadeDeleteConvention>(); 

Answer 1

Unfortunately EF Core currently (latest at this time v2.0) does not expose a good way to control the conventions globally.

The default EF Core 2.0 convention is to use DeleteBehavior.Cascade for required and DeleteBehavior.ClientSetNull for optional relationships. What I can suggest as workaround is a typical metadata model loop at the end of the OnModelCreating override. In this case, locating all the already discovered relationships and modifying them accordingly:

protected override void OnModelCreating(ModelBuilder modelBuilder) {     // ...      var cascadeFKs = modelBuilder.Model.GetEntityTypes()         .SelectMany(t => t.GetForeignKeys())         .Where(fk => !fk.IsOwnership && fk.DeleteBehavior == DeleteBehavior.Cascade);      foreach (var fk in cascadeFKs)         fk.DeleteBehavior = DeleteBehavior.Restrict;      base.OnModelCreating(modelBuilder); }