Learn more about the CData ADO.NET Provider for Apache Cassandra or download a free trial:
Entity Framework はobject-relational mapping フレームワークで、データをオブジェクトとして扱うために使われます。Visual Studio のADO.NET Entity Data Model ウィザードを実行するとEntity Model を作成できますが、このモデルファーストアプローチでは、データソースに変更があった場合やエンティティ操作をより制御したい場合は不都合があります。この記事では、CData ADO.NET Provider を使いコードファーストアプローチでCassandra data にアクセスします。
Set the Server, Port, and Database connection properties to connect to Cassandra. Additionally, to use internal authentication set the User and Password connection properties.
<configuration>
... <connectionStrings>
<add name="CassandraContext" connectionString="Offline=False;Database=MyCassandraDB;Port=7000;Server=127.0.0.1;" providerName="System.Data.CData.Cassandra" />
</connectionStrings>
<entityFramework>
<providers>
... <provider invariantName="System.Data.CData.Cassandra" type="System.Data.CData.Cassandra.CassandraProviderServices, System.Data.CData.Cassandra.Entities.EF6" />
</providers>
<entityFramework>
</configuration>
</code>
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Data.Entity.ModelConfiguration.Conventions;
class CassandraContext :DbContext {
public CassandraContext() { }
protected override void OnModelCreating(DbModelBuilder modelBuilder) { // To remove the requests to the Migration History table
Database.SetInitializer<CassandraContext>(null); // To remove the plural names modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
}
}
using System.Data.Entity.ModelConfiguration;
using System.ComponentModel.DataAnnotations.Schema;
public class Customer {
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public System.String Id { get; set; }
public System.String City { get; set; }
}
public class CustomerMap :EntityTypeConfiguration<Customer> {
public CustomerMap() {
this.ToTable("Customer");
this.HasKey(Customer => Customer.Id);
this.Property(Customer => Customer.City);
}
}
public DbSet<Customer> Customer { set; get; }
CassandraContext context = new CassandraContext();
context.Configuration.UseDatabaseNullSemantics = true;
var query = from line in context.Customer select line;