HasPrincipalKey也可以用于此目的,但这样做并不常见。 如果对HasForeignKey的调用中未指定任何属性,并且主键适用,则将其用作外键。 对于未按约定发现关系的导航、外键或必需/可选性质的情况,可以显式配置这些内容。 例如: C# protectedoverridevoidOnModelCreating(ModelBuilder modelBuilder){ modelBuilder.Entity<Blog>(...
依慣例不會探索此關聯性,因為 EF 一律會依慣例建立與主鍵的關聯性。 您可以使用 對HasPrincipalKey的呼叫明確設定OnModelCreating。 例如: C# protectedoverridevoidOnModelCreating(ModelBuilder modelBuilder){ modelBuilder.Entity<Blog>() .HasOne(e => e.Header) .WithOne(e => e.Blog) .HasPrincipalKey<Blog...
.HasPrincipalKey(p=>new{ p.countryKey, p.name }); Surrogate Key vs Natural Key, 争论多年 https://www.mssqltips.com/sqlservertip/5431/surrogate-key-vs-natural-key-differences-and-when-to-use-in-sql-server/ 2 个都有好处坏处. ef core 对 Natural Key 支持比较弱. 使用Alternate Keys 来实...
HasPrincipalKey 也可以傳遞替代索引鍵屬性的名稱做為字串。 例如,針對單一屬性索引鍵:C# 複製 protected override void OnModelCreating(ModelBuilder modelBuilder) { modelBuilder.Entity<Blog>() .HasMany(e => e.Posts) .WithOne(e => e.Blog) .HasPrincipalKey("AlternateId"); } ...
(p => p.BlogUrl) .HasPrincipalKey(b => b.Url); } } public class Blog { public int BlogId { get; set; } public string Url { get; set; } public List<Post> Posts { get; set; } } public class Post { public int PostId { get; set; } public string Title { get; set; }...
(x => x.BT_Inv_Stockin)//设置BT_Inv_Stockin_Detail可以找到一个BT_Inv_Stockin,表示多对一关系.HasPrincipalKey(p => p.Id)//设置BT_Inv_Stockin主表的关系键.HasForeignKey(l => l.EntryID)//设置BT_Inv_Stockin_Detail从表的关系键.OnDelete(DeleteBehavior.ClientSetNull);//设置级联删除效果}...
1、监听EF执行sql的方式 db.Database.Log += c => Console.WriteLine($"sql：{c}"); SQL Server...
Interception for when EF Core has finished consuming a result set, but before that result set is closed Interception for creation of a DbConnection by EF Core Interception for DbCommand after it has been initialized In addition, EF7 includes new traditional .NET events for: When an entity...
These types must be included in the EF Core model: Copy modelBuilder.Entity<Employee>(); modelBuilder.Entity(typeof(Report)).HasNoKey(); Notice that Report has no primary key and so must be configured as such. Finally, a .NET method must be mapped to the TVF in the database. This ...
EF Core can handle that thanks to shadow properties. And once again, anonymous types come to the rescue with HasData to seed the related data that requires you to supply the value of the foreign key column. Seeding Owned Entities Owned entities, also known as owned types, are the way EF...