using System; using System.Collections.Generic; public partial class Student { public Student() { this.Courses = new HashSet<Course>(); } public int StudentID { get; set; } public string StudentName { get; set; } public Nullable<int> StandardI…

using System; using System.Collections.Generic; public partial class Student { public Student() { this.Courses = new HashSet<Course>(); } public int StudentID { get; set; } public string StudentName { get; set; } public Nullable<int> StandardI…

Student studentToDelete; . Get student from DB using (var ctx = new SchoolDBEntities()) { studentToDelete = ctx.Students.Where(s => s.StudentName == "Student1").FirstOrDefault<Student>(); } //Create new context for disconnected scenario…

//Create student in disconnected mode Student newStudent = new Student() { StudentName = "New Single Student" }; //Assign new standard to student entity newStudent.Standard = new Standard() { StandardName = "New Standard" }; //add new…

实体框架的持久化 当用EntityFramework持久化一个对象时,有两种情形:连接的和断开的 1.连接场景:使用同一个context上下文从数据库中查询和持久化实体时,查询和持久化实体期间,context不会被销毁 2.断开场景:实体的查询和保存提交使用不同的context上下文 上图所示,context1查询数据库中的实体然后被销毁,当实体变化时,应用程序使用context2来提交 这种情形是复杂的,因为新的context上下文不知道实体的变化,所以你不得不通知上下文. CRUD Oper…

To migrate your existing Entity Framework 4.x project to Entity Framework 5.0 using VS2012, first target .NET Framework 4.5: Second, remove the existing Entity Framework 4.1/4.3 reference and install Entity Framework 5.0 from NuGet: Search for Entity…

Add New Entity using DBContext in Disconnected Scenario: In this chapter you will learn how to add new entity in DbContext in the disconnected scenario, which in turn inserts a new row in a database table. If you use Database-First approach, then cre…

Entity Framework DBContext 增删改查深度解析 有一段时间没有更新博客了,赶上今天外面下雨,而且没人约球,打算把最近对Entity Framework DBContext使用的心得梳理一下,早些时候在网上简单查过,对于最新版本的EF并没有类似的知识梳理类文章,希望对大家有所帮助. 1. 不要Code first, 也不要DB first 我为什么讨厌Code first和DB first呢?首先Code first是先写代码,数据库完全由代码生成,开发阶段尚可,一旦到了产…

DBSet类表示一个实体的集合,用来创建.更新.删除.查询操作,DBSet<TEntity>是DBSet的泛型版本 你可以使用DbContext获取DBSet的引用,例如dbContext.Students DBSet中的一些重要方法 Method Name Return Type Description Add Added entity type Adds the given entity to the context the Added state. When the changes ar…

DbContextScope A simple and flexible way to manage your Entity Framework DbContext instances. DbContextScope was created out of the need for a better way to manage DbContext instances in Entity Framework-based applications. The commonly advocated met…