Scaffolded code of Entity Framework Core with Interbase DB results in an error querying record from a table

Question

I try to make a library for access to an Interbase database on a server. Following the samples provided by embarcadero here I end up with a scaffolded database context without any error.

public partial class CZehetnerDBWPSTEYRXEIBContext : DbContext
{
    public CZehetnerDBWPSTEYRXEIBContext()
    {
    }

    public CZehetnerDBWPSTEYRXEIBContext(DbContextOptions<CZehetnerDBWPSTEYRXEIBContext> options)
        : base(options)
    {
    }

    public virtual DbSet<Aktion> Aktions { get; set; } = null!;
    ...
    // this is the table I want to query
    public virtual DbSet<Executedalarm> Executedalarms { get; set; } = null!;
    ......


    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        if (!optionsBuilder.IsConfigured)
        {
            optionsBuilder.UseInterBase("Same as used for scaffolding, onnection is OK");
        }
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        ....
        modelBuilder.Entity<Executedalarm>(entity =>
            {
                entity.HasKey(e => e.LfdNr)
                    .HasName("RDB$PRIMARY9");

                entity.ToTable("EXECUTEDALARMS");

                entity.HasIndex(e => e.Executed, "EXECUTEDALARMS_IDXDT");

                entity.Property(e => e.LfdNr).HasColumnName("LFD_NR");

                entity.Property(e => e.AaId).HasColumnName("AA_ID");

                entity.Property(e => e.Alarmsource)
                    .HasMaxLength(50)
                    .HasColumnName("ALARMSOURCE");

                entity.Property(e => e.Alarmtext)
                    .HasMaxLength(120)
                    .HasColumnName("ALARMTEXT");

                entity.Property(e => e.Annahme).HasColumnName("ANNAHME");

                entity.Property(e => e.Computer)
                    .HasMaxLength(50)
                    .HasColumnName("COMPUTER");

                entity.Property(e => e.Ersrte)
                    .HasColumnType("CHAR(1)")
                    .HasColumnName("ERSRTE")
                    .HasDefaultValueSql("'N'");

                entity.Property(e => e.Executed).HasColumnName("EXECUTED");

                entity.Property(e => e.Hdld)
                    .HasColumnType("CHAR(1)")
                    .HasColumnName("HDLD");

                entity.Property(e => e.IdAr).HasColumnName("ID_AR");

                entity.Property(e => e.IdIt).HasColumnName("ID_IT");

                entity.Property(e => e.IdPrio).HasColumnName("ID_PRIO");

                entity.Property(e => e.IdRcv).HasColumnName("ID_RCV");

                entity.Property(e => e.IdStation).HasColumnName("ID_STATION");

                entity.Property(e => e.Itimestamp).HasColumnName("ITIMESTAMP");

                entity.Property(e => e.Name)
                    .HasMaxLength(50)
                    .HasColumnName("NAME");

                entity.Property(e => e.Number)
                    .HasMaxLength(20)
                    .HasColumnName("NUMBER");

                entity.Property(e => e.Sds)
                    .HasMaxLength(5)
                    .HasColumnName("SDS");

                entity.Property(e => e.Sms)
                    .HasMaxLength(20)
                    .HasColumnName("SMS");

                entity.Property(e => e.Success).HasColumnName("SUCCESS");

                entity.Property(e => e.UrId).HasColumnName("UR_ID");

                entity.Property(e => e.Username)
                    .HasMaxLength(30)
                    .HasColumnName("USERNAME");

                entity.HasOne(d => d.Ur)
                    .WithMany(p => p.Executedalarms)
                    .HasForeignKey(d => d.UrId)
                    .OnDelete(DeleteBehavior.Restrict)
                    .HasConstraintName("FK_EXECUTED_REF_580_USERREGI");
            });
            ....

This is all generated code from the Scaffold-DbContext command, I have not changed anything.

Now when I try to use this scaffolded model, I ran into an exception:

using (CZehetnerDBWPSTEYRXEIBContext db = new CZehetnerDBWPSTEYRXEIBContext())
{
    // throws exception
    var alarms = db.Executedalarms.Where(p => p.LfdNr == 1000).ToList();
}

InterBaseSql.Data.InterBaseClient.IBException:

'Dynamic SQL Error SQL error code = -104 Token unknown - line 1, column 11.'

Does anyone know what this means? What is SQL error code -104? Which "Token" may be wrong here?

Here is the generated code for the class of the record:

public partial class Executedalarm
{
    public int LfdNr { get; set; }
    public int? UrId { get; set; }
    public DateTime? Annahme { get; set; }
    public DateTime? Executed { get; set; }
    public int? IdStation { get; set; }
    public int? IdRcv { get; set; }
    public int? IdIt { get; set; }
    public string? Number { get; set; }
    public string? Sms { get; set; }
    public string? Name { get; set; }
    public string? Alarmtext { get; set; }
    public string? Alarmsource { get; set; }
    public string? Computer { get; set; }
    public string? Username { get; set; }
    public int? AaId { get; set; }
    public int? Success { get; set; }
    public int? Itimestamp { get; set; }
    public string? Hdld { get; set; }
    public int? IdAr { get; set; }
    public int? IdPrio { get; set; }
    public string? Ersrte { get; set; }
    public string? Sds { get; set; }

    public virtual Userregist? Ur { get; set; }
}

Interesting, this works ...

var alarms = db.Executedalarms.FromSqlRaw($"SELECT * FROM EXECUTEDALARMS WHERE Lfd_Nr = 1000").ToList();