1. 问题: 变量id2的值是1,还是2? 假如如下面的注释操作,movies2有几条记录?里面会包含ID = 1的记录吗?
var id1 = db.Movies.First().ID;var movies1 = db.Movies.ToList();var movie = from m in db.Movieswhere m.ID.Equals(1)select m;movie.First().ID = 2;var id2 = db.Movies.First().ID;//下面设置断点,运行到断点处后,手动向数据库中再添加一条记录var movies2 = db.Movies.ToList();
2. 问题: movie2的price是多少?
var movie1 = db.Movies.Find(1);movie1.Price = 100;var movie2 = db.Movies.Find(1);
3. 下面movie1和move2的类型一样吗?User1和User2类型一样吗?
定义了下面的Model
public class Movie { public int ID { get; set; } public string Title { get; set; } public DateTime ReleaseDate { get; set; } public string Genre { get; set; } public decimal Price { get; set; } public virtual Category Category { get; set; } } public class Category { public int ID { get; set; } public string Name { get; set; } public virtual ICollectionMovies { get; set; } } public class User { public string Name{ get;set;} }
使用不同的方式创建Movie, User对象
var movie1 = db.Movies.Create();var movie2 = new Movie();var user1 = db.User.Create();var user2 = new User();