我需要在ASP.NET MVC 5的角色标识表中添加一个额外的字段。什么是ASP.NET迁移中的Discriminator列?
我使用迁移。
我添加的扩展,对于喜欢角色:
public class ApplicationRole : IdentityRole
{
public ApplicationRole() : base() { }
public ApplicationRole(string name)
: base(name)
{
}
public virtual Project Project { get; set; }
}
我的移民类,我得到的是:
public partial class ProjectToIdentity : DbMigration
{
public override void Up()
{
CreateTable(
"dbo.Projects",
c => new
{
ID = c.Int(nullable: false, identity: true),
ProjectName = c.String(maxLength: 100),
})
.PrimaryKey(t => t.ID);
AddColumn("dbo.AspNetRoles", "Discriminator", c => c.String(nullable: false, maxLength: 128));
AddColumn("dbo.AspNetRoles", "Project_ID", c => c.Int());
CreateIndex("dbo.AspNetRoles", "Project_ID");
AddForeignKey("dbo.AspNetRoles", "Project_ID", "dbo.Projects", "ID");
}
public override void Down()
{
DropForeignKey("dbo.AspNetRoles", "Project_ID", "dbo.Projects");
DropIndex("dbo.AspNetRoles", new[] { "Project_ID" });
DropColumn("dbo.AspNetRoles", "Project_ID");
DropColumn("dbo.AspNetRoles", "Discriminator");
DropTable("dbo.Projects");
}
}
的问题是 - 什么是鉴别列?我的模型中没有这样的列。为什么迁移工具增加了这个领域,它有什么目标?
它用于表继承计划。这里有一个很好的描述http://weblogs.asp.net/manavi/inheritance-mapping-strategies-with-entity-framework-code-first-ctp5-part-1-table-per-hierarchy-tph。 – Jasen 2015-01-20 20:15:35
有没有人能够摆脱这种情况下的'Discriminator'列?我明白为什么EF添加它,但在我的情况下,我只想坚持'ApplicationRole' - 不会有'IdentityRole's。如果可以的话,我会把它做成“抽象的”,但它在nuget包中,所以这是不可能的。 – 2016-02-05 16:49:43