How to define Generator (from Firebird) for an Entity framework 6 model field?

Question

For example:

I have the following table:

TABLE_EXAMPLO 
-----------
ID         
NAME       

And the following Generator:

TABLE_EXAMPLO_GEN

How I would map the entity so that the Entity Framework can call Generator for new records?

In Nhibernate it was necessary something like this, in ClassMap<T>:

Id(t => t.Id).GeneratedBy.Native("TABLE_EXAMPLO_GEN").Column("ID");
// ou
Id(t => t.Id).GeneratedBy.Sequence("TABLE_EXAMPLO_GEN").Column("ID");

And in Entityframwork it’s possible?

Note: I already have (in legacy system) a Firebird database in this format, with Generator for primary keys (no triggers).

Answer 1

With a Firebird database, a table was created with the following fields:

/* Table: CLIENTE, Owner: SYSDBA */

CREATE TABLE "CLIENTE" 
(
  "ID"   INTEGER NOT NULL,
  "NOME"     VARCHAR(50) CHARACTER SET WIN1251 NOT NULL,
  CONSTRAINT "PK_CLIENTE" PRIMARY KEY ("ID")
);    

and for auto-increment of the field ID one Generator:

/* Triggers only will work for SQL triggers */
SET TERM ^ ;
CREATE TRIGGER "SET_CUST_NO" FOR "CLIENTE" 
ACTIVE BEFORE INSERT POSITION 0
AS
BEGIN
    if (new.ID is null) then
    new.ID = gen_id(cust_no_gen, 1);
END
 ^    
COMMIT WORK ^
SET TERM ;^

thus, the entire register ID will be incremented.

---

How to configure Entityframework to work mapping:

Download the packages:

• Entityframework 6.1.3
• Firebird Entity Framework Provider 5.1.0
• Firebird ADO.NET Data Provider 5.1.0

Classes:

1) Model:

public class Cliente
{
    public int Id { get; set; }
    public string Nome { get; set; }
}

2) Mapping:

public sealed class ClienteConfiguration: EntityTypeConfiguration<Cliente>
{
    public ClienteConfiguration()
    {
        ToTable("CLIENTE");

        HasKey(c => c.Id)
            .Property(c => c.Id)
            .HasColumnName("ID")
            .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

        Property(c => c.Nome)
            .HasColumnName("NOME")
            .HasMaxLength(50);
    }
}

3) Context

public sealed class Database: DbContext
{
    public Database()
        :base("FireBirdConnectionString")
    {
    }
    public DbSet<Cliente> Cliente { get; set; }
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Configurations.Add(new ClienteConfiguration());            
    }
}

4) Configuration of connection:

<connectionStrings>
    <add name="FireBirdConnectionString"
    connectionString="DataSource=localhost; User=SYSDBA;Password=masterkey; Database=C:\Temp\TUTORIAL.FDB;" 
    providerName="FirebirdSql.Data.FirebirdClient" />
</connectionStrings>

---

Your questioning:

How I would map the entity so that the Entity Framework can call Generator for new records?

Was placed .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity), and it worked, it was removed this setting, it also worked, that is to say, the Provider is in charge of executing the Insert with Generator, unshaped.

So, if your table is set to Generator the provider: Firebird Entity Framework Provider does the action and returns you in classe the ID generated.