we'll use PersonId as the key property. And since that is not a conventional key property, it needs to be configured as such with the Key Data Annotation (Example 4-20).
EntityFramework6.X 之Primary/Foreign Key Primary Key 默认情况下EF会将实体类中属性名称为Id或<class name>Id的属性作为主键,若是采用其他格式的跟随Id命名的属性,将会抛出异常,如下stdId并不是全称,将会抛出 Foreign Key 在EF中有导航属性,若没有指定外键属性,则系统自动为导航属性设置外键属性,当然也可以手工...
I still have some problems (setting FKs in constructor for example) but I'll now wait for next release instead of adding some code in my framework. Chris Anonymous March 17, 2009 Kristofer and Michael, The idea is to create a fake entity and attach that, to save the query to the data...
命名空間: Microsoft.EntityFrameworkCore.Migrations.Operations 組件: Microsoft.EntityFrameworkCore.Relational.dll 套件: Microsoft.EntityFrameworkCore.Relational v9.0.0 來源: DropForeignKeyOperation.cs 包含外鍵條件約束的資料表。 C# 複製 public virtual string Table { get; set; } 屬...
(or set of columns) with a value that corresponds to a primary key value in theCustomertable. ACustomerclass might have a property namedOrdersthat contains a collection of instances of theOrderclass, while theCustomertable in a database has no comparable column. The Entity Framework provides ...
Static methods that are useful in application code where there is not an EF type for the method to be accessed from. For example, referencing a shadow state property in a LINQ query. EntityFrameworkQueryableExtensions Entity Framework LINQ related extension methods. ...
The following example will change the initializer back to the default functionality that will create the database only if it doesn’t exist: XML <appSettings><addkey="DatabaseInitializerForType Blogging.BlogContext, Blogging"value="System.Data.Entity.CreateDatabaseIfNotExists EntityFramework"/></app...
Entity Framework - First Example - Let’s define a very simple model using classes. We’re just defining them in the Program.cs file but in a real-world application you will split your classes into separate files and potentially a separate project. Follo
Other default conventions supported by EF include the ability to automatically identify primary-key and foreign keys based on common naming patterns (for example: an ID or DinnerID property on the Dinner class will be inferred as the primary key). EF also includes smart conventions for wiring-up...
By default Entity Framework will lazy load any related entities. If you’ve not come across Lazy Loading before it’s basically coding something in such a way that either the item is not retrieved and/or not created until you actually want to use it. For example, the code below shows the...