大家还记得Entity Framework 4.1/4.3 之一(概念篇)中我介绍过ObjectContext ObjectSet 以及 DBContext 和DBSet的定义。在使用了4.0很长一段时间后,我向4.3进行了过渡,这个过渡的过程中,我认识并使用了 DBContext 和 DBSet 。感觉很不错。下面我通会表格来分别展示一下ObjectContext ObjectSet DBContext DBSet: 通过...
将Find函数的输入值一一包装成KeyValuePair,并最终生成EntityKey对象。 之后,Find函数调用了FindInStateManager函数。顾名思义,EF首先在内部缓存中查找对应实体。对于状态是Unchanged、Modified以及Deleted的实体,FindInStateManager直接使用了过去ObjectContext.ObjectStateManager.TryGetObjectStateEntry方法,并且直接将EntityKey传给...
In order to use Entity framework core, we need to define the DbSet property for each entity (or tables). Then we need to configure the model & define relationships between the entities using the ModelBuilder API Once we have these in place, then we can Write and execute queries against ...
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(定义实体数据模型,...
DbSet<TEntity> DbUpdateConcurrencyException DbUpdateException DeleteBehavior DeleteBehaviorAttribute EF EntityFrameworkQueryableExtensions EntityState EntityTypeConfigurationAttribute EntityTypeConfigurationAttribute<TConfiguration,TEntity> EntityTypeExtensions ExecutionStrategyExtensions ...
http://www.tutorialspoint.com/entity_framework/entity_framework_dbcontext.htmMonday, August 1, 2016 1:49 PMyou did not answer this point which i asked : also tell me DbContext and DbSet is related to EF code first or DB first.please answer...
今天为大家带来DbSet.Local属性的使用与实现。和上次介绍的Find函数首先查找context中缓存的实体类似,DbSet的Local属性也是返回context中缓存并且被跟踪的实体。不同点在于,Local属性不会返回状态为EntityState.Deleted的实体,且即使缓存中什么实体都没有,也不会对数据库进行访问。这样的设计也正符合Local(本地)之意。
// In this rare case if this is a problem for the app, then the app can just not use this mechanism to create // DbSet instances, and this code becomes a no-op. However, if this set initializer is then saved and used later // for the Set method, then it makes the problem bigg...
I couldn't get much help from google, and I am not sure what I am missing. Can anyone please help me! namespace Books.API.Contexts { public class BooksContext : DbContext { public DbSet<Book> Books { get; set; } public BooksContext(DbContextOptions<BooksContext> options) : base(...
publicstringUserName { get;set; } } 3.创建DbContext publicclassMyDbContext:DbContext { public DbSet<User> Users { get;set; } publicMyDbContext(DbContextOptions<MyDbContext> options):base(options) { } 4.StartUp配置 var provi...