Wsrtjtyk

Since Table Per Type isn't available in Core, I had to do a bit of a workaround to get my entities how I like them. Essentially I have a base class with its properties, and a navigation property to its parent:

 public class Provision

{

    public Guid ProvisionId { get; set; }

    public string ProvisionName { get; set; }

    public string ProvisionDescription { get; set; }



    public Provision(){}

}



 public class CompanyLeaveProvision 

{

    public Guid ProvisionId { get; set; }

    public int CompanyId { get; set; }

    public Provision Provision { get; set; }



    public CompanyLeaveProvision() { }

}

Configurations:

public void Configure(EntityTypeBuilder<Provision> builder)

    {

        // Primary Key

        builder.HasKey(t => t.ProvisionId);



        // Properties

        builder.Property(t => t.ProvisionName)

            .IsRequired()

            .HasMaxLength(40);



        builder.Property(t => t.ProvisionDescription)

            .HasMaxLength(500);



        // Table & Column Mappings

        builder.Property(t => t.ProvisionId).HasColumnName("ProvisionID");

        builder.Property(t => t.ProvisionName).HasColumnName("ProvisionName");

        builder.Property(t => t.ProvisionDescription).HasColumnName("ProvisionDescription");

        builder.ToTable("Provision", "Organization");

}



        public void Configure(EntityTypeBuilder<CompanyLeaveProvision> builder)

    {

        // Primary Key

        builder.HasKey(t => t.ProvisionId);



        // Properties 

        builder.Property(t => t.ProvisionId)

            .IsRequired();



        builder.Property(t => t.CompanyId)

            .IsRequired();





        // Table & Column Mappings

        builder.ToTable("CompanyLeaveProvision", "Organization");

        builder.Property(t => t.ProvisionId).HasColumnName("ProvisionID");

        builder.Property(t => t.CompanyId).HasColumnName("CompanyID");





        builder.HasOne(t => t.Provision).WithOne().HasForeignKey<Provision>(t => t.ProvisionId);







    }

My context:

ProvisionContext: DbContext, IContext    {

    public DbSet<Provision> Provisions { get; set; }

    public DbSet<CompanyLeaveProvision> CompanyLeaveProvisions { get; set;} 

    // OnModelCreating and other code below

 }

I have a foreign key constraint on the the Organization.CompanyProvision table that references the ProvisionId property on the Organization.Provision table.

What is happening is the CompanyProvision is being inserted before the base Provision, resulting in this error:

The INSERT statement conflicted with the FOREIGN KEY constraint
"fk_CompanyLeaveProvision_Provision". The conflict occurred in
database "Dev", table "Organization.Provision", column 'ProvisionID'.

To attempt to save, here is the code I am calling:

    _context.Entry(command.Provision.Provision).State = EntityState.Added;

    _context.Entry(command.Provision).State = EntityState.Added;

    await _context.SaveChangesAsync();

Aside from calling SaveChanges() after each _context.Entry(MyEntity).State = EntityState.Added, is there any way around this issue? I would prefer to have these save at once. I know a stored procedure is also an option, but I would prefer not to do that.

Thank you for your help!

It's because this fluent mapping

.HasForeignKey<Provision>(t => t.ProvisionId)

is telling EF Core that Provision is the dependent entity and has FK to the principal entity CompanyLeaveProvision, while the database model is the opposite.

So simply change Provision to CompanyLeaveProvision

.HasForeignKey<CompanyLeaveProvision>(t => t.ProvisionId)