EF4 CodeFirst CTP5 nvarchar(max)via属性

Question

有没有办法创建一个自定义属性,使EF CodeFirst 在分配给poco类的属性时使用nvarchar(max)作为数据类型？我知道这可以通过流畅的api实现,但我们希望将所有定义放在一个地方,这就是元数据类.

流畅的API:

modelBuilder.Entity<Event>().Property(p => p.TicketText).HasColumnType("nvarchar(max)");

Answer 1

public class NVarcharMaxAttribute : Attribute { }

public class NVarcharMaxAttributeConvention : AttributeConfigurationConvention<PropertyInfo, StringPropertyConfiguration, NVarcharMaxAttribute> {
    public override void Apply(PropertyInfo memberInfo, StringPropertyConfiguration configuration, NVarcharMaxAttribute attribute) {
        configuration.ColumnType = "nvarchar(max)";
    }
}

protected override void OnModelCreating(ModelBuilder modelBuilder) {
    modelBuilder.Conventions.Add<NVarcharMaxAttributeConvention>();
}

Answer 2

[System.ComponentModel.DataAnnotations.MaxLength]