Entity Framework Code First

標籤：

首先需要分析業務，提取項目需要的概念性模型，將其用代碼錶示。

基本類型，枚舉類型，複雜類型，以及它們之間的關係，繼承，彙總，組合等方式。

枚舉類型在Entity Framework 6 中已支援，可直接定義使用

複雜類型可在 使用[ComplexType] 標註在類上，也可在 FluentAPI 定義

繼承在映射到資料表，預設是TPH 所有的屬性對應到基類表中。

也可使用如下代碼將每一個類型映射到一張表上

modelBuilder.Entity<PORequestEntry>().ToTable("PORequestEntrys"); 

如需將每個子類極其繼承屬性對應到一張表中，可使用MapInheritedProperties  方法。

modelBuilder.Entity<PORequestEntry>().Map(m =>{  m.MapInheritedProperties();  m.ToTable("PORequestEntry");});

將同一類型映射到不同表

modelBuilder.Entity<PORequest>().Map(m=>{  m.Properties(t => new{ t.FBillNo, t.FDate });  m.ToTable(PORequest);}).Map(m=>{  m.Properties(t=> new { t.PoAddress.StreetNumber, t.PoAddress.StreetName });  m.ToTable(PORequestAddress); });

將不同類型映射到同一表

modelBuilder.Entity<PORequestEntry>().ToTable("OtherTable"); 

之後定義上下文，使用Migrations 將定義的結構映射到資料庫中。

如需初始化一些資料，可新增一個繼承DropCreateDatabaseAlways 類的方法在上下文建構函式中調用即可

public class DBInitializer : DropCreateDatabaseAlways<ApplicationDbContext>    {        protected override void Seed(ApplicationDbContext context)        {            MGFunc mgfun1 = new MGFunc();            mgfun1.Id = "001";            mgfun1.FName = "許可權管理";            mgfun1.FUrl = "/Manage/MGFunc/index";            mgfun1.CreatedDate = DateTime.Now;            base.Seed(context);        }    }

 

    public enum POTranType    {        Office = 1,        WearHourse = 2    }    public class PORequest : AuditableEntity    {        [MaxLength(100)]        public string FBillNo { set; get; }        public DateTime FDate { set; get; }        public POTranType FTranType { set; get; }        [MaxLength(100)]        public string FStatus { set; get; }        [MaxLength(200)]        public string FNote { set; get; }        public Address PoAddress { set; get; }        public List<PORequestEntry> PORequestEntrys { set; get; }    }    [ComplexType]    public class Address    {        [MaxLength(50)]        public string StreetNumber { get; set; }        [MaxLength(200)]        public string StreetName { get; set; }    }    public class PORequestEntry : AuditableEntity    {        [MaxLength(100)]        public string FInterID { set; get; }        [Required]        [Range(0, 500)]        public decimal FQty { set; get; }        public decimal FPrice { set; get; }        public decimal FSecQty { set; get; }        [MaxLength(100)]        public string FItemID { set; get; }        [ForeignKey("FItemID")]        public ItemCore FItem { set; get; } 

View Code

 public class ApplicationDbContext : DbContext    {         public DbSet<MGFunc> MGFunc { set; get; }        public DbSet<ItemCore> ItemCore { set; get; }        public DbSet<PORequest> PORequest { set; get; }        public DbSet<PORequestEntry> PORequestEntry { set; get; }        public ApplicationDbContext()            : base("SeCommerce2")        {            //Database.SetInitializer<ApplicationDbContext>(new DBInitializer());                   }        protected override void OnModelCreating(DbModelBuilder modelBuilder)        {            //modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();            //modelBuilder.Conventions.Add<StoreGeneratedIdentityKeyConvention>();                        base.OnModelCreating(modelBuilder);        }    }

View Code

 

Entity Framework Code First