Question

为什么这个EF 6代码会产生意外的代码优先迁移结果？我希望这段代码只生成一个自引用FK的ParentId。这是基于最后附带的基于EF 4.1的文章。在这种情况下，EF 6中是否有任何可能影响行为的变化？

实体：

% Read the image into the workspace and display it.
A = imread('coins.png');
imshow(A)

% Find all the circles with radius r such that 15 ≤ r ≤ 30.
[centers, radii, metric] = imfindcircles(A,[15 30]);

% Retain the five strongest circles according to the metric values.
centersStrong5 = centers(1:5,:);
radiiStrong5 = radii(1:5);
metricStrong5 = metric(1:5);

% Draw the five strongest circle perimeters.
viscircles(centersStrong5, radiiStrong5,'EdgeColor','b');

代码优先迁移结果：

public class Category
{
  public int CategoryId { get; set; }
  public string Name { get; set; }
  public int? ParentId { get; set; }
  public virtual Category Parent { get; set; }
  public virtual ICollection<Category> Children { get; set; }
}

public class CategoryMap : EntityTypeConfiguration<Category> {
public CategoryMap() {
    HasKey(x => x.CategoryId);

    Property(x => x.CategoryId)
        .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

    Property(x => x.Name)
        .IsRequired()
        .HasMaxLength(255);

    HasOptional(x => x.Parent)
        .WithMany(x => x.Children)
        .HasForeignKey(x => x.ParentId)
        .WillCascadeOnDelete(false);
 }
}

代码优先迁移期望：

        CreateTable(
            "dbo.Categories",
            c => new
                {
                    CategoryId = c.Int(nullable: false, identity: true),
                    Name = c.String(),
                    ParentId = c.Int(),
                    Parent_CategoryId = c.Int(),
                })
            .PrimaryKey(t => t.CategoryId)
            .ForeignKey("dbo.Categories", t => t.Parent_CategoryId)
            .Index(t => t.Parent_CategoryId);

您可以将此作为参考，以获取更多详细信息：http://dotnet.dzone.com/news/using-self-referencing-tables

EF自引用实体

0 个答案: