当调用SaveChanges方法时,EntityFramework默认情况下总是先对所有已经变化的实体类中所有的属性值进行检测,如果你需要更新大批量的数据实体并且这些实体已经通过了验证,那么这一步显然多余,你可以通过暂时性地关闭验证机制使得保存数据的进度花费更少的时间(借助“”属性进行设置)。关于此更多的信息你可以参考EntityFramework...
If you've had many-to-many relationships when using the database-first strategy, you may be familiar with the fact that Entity Framework can create many-to-many mappings when the database join table contains only the primary keys of the related entities. This mapping rule is the same for ...
如需詳細資訊,請參閱HOW TO:明確載入相關的物件 (Entity Framework)。 定義查詢路徑來為查詢結果定形 若要指定查詢路徑,請將代表物件圖形的字串傳遞給ObjectQuery上的Include方法。 這個路徑會指定在執行物件查詢時要傳回哪些相關實體。 例如,在Contact物件的查詢上定義的查詢路徑可確保將會傳回每個相關的SalesOrderHead...
Entity Framework 预览:代码优先,ObjectSet 和 DbContext Julie Lerman Entity Framework (EF) 4 仍处于测试阶段,但开发团队已开始通过另一种方式使用它了。我们具备用于创建模型的数据库优先方式(将数据库反向工程为实体数据模型)和新的 EF 4 模型优先功能(定义实体数据模...
(For more on LINQ operators, see the Data Points column " Standard Query Operators with LINQ .") The Entity Framework does not provide lazy-loading capability out of the box, as does LINQ to SQL, so you are required to indicate explicitly which related entities you wish to include in ...
HasOne<TRelatedEntity>(String) Configures a relationship where this entity type has a reference that points to a single instance of the other type in the relationship. HasOneBuilder(EntityType, PropertyInfo) This API supports the Entity Framework Core infrastructure and is not intended to be...
EntityFrameworkQueryableExtensions Entity Framework LINQ related extension methods. EntityTypeConfigurationAttribute Specifies the configuration type for the entity type. EntityTypeConfigurationAttribute<TConfiguration,TEntity> Specifies the configuration type for the entity type. ...
以Northwind为示例数据库,ADO.NET Entity Framework之Linq To Entities Select - 选择需要返回的字段 Where - 筛选 OrderBy - 正序排序 OrderByDescending - 倒序排序 ThenBy - 在 OrderBy 或 OrderByDescending 的基础上再正序排序 ThenByDescending - 在 OrderBy 或 OrderByDescending 的基础上再倒序排序 GroupBy ...
Normally we load related entities using LoadProperty in the context or use Include in the Linq query. Both approach wont work here in generic approach as we do not know the properties to do this. I searched a lot to achieve eager loading in a generic mode. But nothing worked then thought...
想通过指定的City把Customers和相关的CreditCards以及Transactions都加载,但不用Include()方法.式加载实体和让EF维护关联,如代码Listing13-26所示 Listing 13-26.Loading Related Entities without Using Include() using (var context = new Recipe9Context()) ...