EF Core如何添加主键 [英] EF Core how add Primary Key
问题描述
我在SQLite的Ef核心模型中有了这个类定义。
I have this class definition into Ef Core Model for SQLite.
public class Ejercicios : BaseModel
{
private int _TipoEjercicio;
[Key]
public int TipoEjercicio
{
get { return _TipoEjercicio; }
set { SetProperty(ref _TipoEjercicio, value); }
}
private string _DescripcionEjercicio;
public string DescripcionEjercicio
{
get { return _DescripcionEjercicio; }
set { SetProperty(ref _DescripcionEjercicio, value); }
}
private string _HexForeColor;
public string HexForeColor
{
get { return _HexForeColor; }
set { SetProperty(ref _HexForeColor, value); }
}
private string _HexBackGroundColor;
public string HexBackGroundColor
{
get { return _HexBackGroundColor; }
set { SetProperty(ref _HexBackGroundColor, value); }
}
}
现在,我的问题是当我尝试运行添加迁移,抛出
Now my problem is when I try to run Add-Migration, throws
System.InvalidOperationException: The entity type 'Ejercicios' requires a primary key to be defined.
如何为sqlite的EF核心模型添加主键?
How to add primary key to an EF Core Model for sqlite ?
编辑1:模型生成器
public class MyContext : DbContext
{
public DbSet<Ejercicios> Ejercicios { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlite("Filename=MyDb.db");
}
}
推荐答案
为什么您不使用流利的api 吗?
modelBuilder.Entity<Ejercicios>()
.HasKey(p => new p.TipoEjercicio);
尝试一下,我认为您的问题现在已经解决。
Try this out, i think your problem is now solved.
---更新---
创建您的 DbContext
首先:
public class MyDbContext : DbContext
{
public MyDbContext()
: base("name=MyConnection")
{
Database.SetInitializer(new MigrateDatabaseToLatestVersion<MyDbContext, YourApplication.Migrations.Configuration>("MyConnection"));
}
public DbSet<Users> Users { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
//here you can MAP Your Models/Entities, but i am going to show you something more interesting. so keep up.
modelBuilder.Configurations.Add(new UsersMap());
}
}
在应用程序根目录中创建一个迁移文件夹,然后使<那里的code> Configuration 类:
Create a Migration Folder in your app root And make Configuration
class there:
internal sealed class Configuration : DbMigrationsConfiguration<YourApplication.Infrastructure.Data.MyDbContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = true;
AutomaticMigrationDataLossAllowed = true;
ContextKey = "YourApplication.Infrastructure.Data.MyDbContext";
}
protected override void Seed(YourApplication.Infrastructure.Data.MyDbContext context)
{
// This method will be called after migrating to the latest version.
// You can use the DbSet<T>.AddOrUpdate() helper extension method
// to avoid creating duplicate seed data. E.g.
//
// context.People.AddOrUpdate(
// p => p.FullName,
// new Person { FullName = "Andrew Peters" },
// new Person { FullName = "Brice Lambson" },
// new Person { FullName = "Rowan Miller" }
// );
//
}
}
我是胚芽怪胎,所以我写的代码很干净。这就是为什么例如当我制作如下的 Model
时,我为每个创建一个
: EntityBase
ID
I am a Germ Freak, so i write my codes very clean. That's why when for example i made a Model
like below, i create an EntityBase
for every Id
:
public class EntityBase
{
public int Id { get; set; }
}
并将其实现为我的 Model
:
public class User: EntityBase
{
public string Example1{ get; set; }
public string Example2{ get; set; }
public string Example3{ get; set; }
}
对于映射,我创建了如下所示的另一个类并使用 Fluent Api
:
And For Mapping I Create another Class like below and use Fluent Api
:
public class UserMap : EntityTypeConfiguration<User>
{
public UserMap()
{
ToTable("TblUser");
HasKey(x => x.Id);
Property(x => x.Example1)
.IsRequired();
//etc
}
}
但是,如果您不想遇到所有麻烦,则可以轻松地将流畅的api插入 DbContext的OnModelCreating
方法中。顺便提一下,如果您使用的是流畅的api,则不应该使用数据注释。快乐编码。
But if you don't want to go through all the trouble you can easily just insert the fluent api in your DbContext's OnModelCreating
Method Like i said at start. By the way be aware if you are using fluent api, you Shouldn't use Data Annotations. Happy Coding.
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