如何为这种类型设置流利的映射?
public class Topic
{
public int Id { get; set; }
public string Title { get; set; }
public virtual ICollection<Topic> Children { get; set; }
public int ParentId { get; set; }
public Topic Parent { get; set; }
public virtual ICollection<Topic> Related { get; set; }
}
答案 0 :(得分:7)
我假设不需要ParentId,因为并非每个主题都有父母。
public class Topic
{
public int Id { get; set; }
public string Title { get; set; }
public int? ParentId { get; set; }
public Topic Parent { get; set; }
public virtual ICollection<Topic> Children { get; set; }
public virtual ICollection<Topic> Related { get; set; }
}
然后映射看起来类似于
public class TopicMap : EntityTypeConfiguration<Topic>
{
public TopicMap()
{
HasKey(t => t.Id);
Property(t => t.Title)
.IsRequired()
.HasMaxLength(42);
ToTable("Topic");
Property(t => t.Id).HasColumnName("Id");
Property(t => t.Title).HasColumnName("Title");
Property(t => t.ParentId).HasColumnName("ParentId");
// Relationships
HasOptional(t => t.Parent)
.WithMany()
.HasForeignKey(d => d.ParentId);
//Topic might have a parent, where if it does, has a foreign key
//relationship to ParentId
}
}
关于模型绑定的插件:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new TopicMap());
//modelBuilder.Configurations.Add(new TopicChildrenMap()); ..etc
//modelBuilder.Configurations.Add(new TopicRelatedMap()); ..etc
}
我还建议您开始the EF Power Tools CTP。这对学习和理解如何创建流畅的配置非常有帮助。
希望有所帮助。