Entity Framework 6.0 对枚举的支持/实体添加后会有主键反回

实验

直接上代码,看结果

实体类

[Flags]

    public enum FlagsEnum

    {

        Day = 1,

        Night = 2

    }

    public class EntityWithEnum

    {

        public int ID { get; set; }



        public FlagsEnum ValidTime { get; set; }



    }

 

数据库上下文

public partial class CodeFirstModel : DbContext

   {

        public CodeFirstModel()

            : base("name=CodeFirstModel")

        {

        }



        public virtual DbSet<EntityWithEnum> EntityWithEnum { get; set; }

}

Sql server LocalDb的连接字符串

<connectionStrings>

    <add name="CodeFirstModel" connectionString="data source=(LocalDb)\MSSQLLocalDb;initial catalog=TestDb;integrated security=True;multipleactiveresultsets=True;application name=EntityFramework" providerName="System.Data.SqlClient" />

  </connectionStrings>

 

主函数

 

static void Main(string[] args)

        {

            //CreateDatabaseIfNotExists

            //DropCreateDatabaseIfModelChanges

            //DropCreateDatabaseAlways

            Database.SetInitializer(new DropCreateDatabaseIfModelChanges<CodeFirstModel>());

            using (var context = new CodeFirstModel())

            {

                context.Database.Initialize(true);

            }





            using(CodeFirstModel db = new CodeFirstModel())

            {

        EntityWithEnum entity = new EntityWithEnum() { ValidTime = FlagsEnum.Day };

                db.EntityWithEnum.Add(entity);



                entity = new EntityWithEnum() { ValidTime = FlagsEnum.Night };

                db.EntityWithEnum.Add(entity);





                entity = new EntityWithEnum() { ValidTime = FlagsEnum.Night| FlagsEnum.Day };

                db.EntityWithEnum.Add(entity);



                db.SaveChanges();

                Console.WriteLine("{0}:\t{1}", entity.ID, entity.ValidTime);

                Console.WriteLine("-------------------");



                var entitys = from e in db.EntityWithEnum

                              where e.ValidTime.HasFlag(FlagsEnum.Day)

                              select e;



                foreach (var item in entitys)

                {

                    Console.WriteLine("{0}:\t{1}", item.ID, item.ValidTime);

                }

                



            }

            Console.ReadKey(true);

}

运行结果

 

结论

Entity Framework 6.0 的 LINQ 是可以直接写 枚举的 HasFlags 方法的.

Add 的实体在 数据库保存后,会将数据库生成好的主键读出来.不用再写LINQ 再查一遍了.