DbContext

SqlQuery會回傳結果集，ExecuteSqlCommand會回傳受影響的筆數 傳遞參數的方式有以下幾種 namespace ConsoleApplication1 { using ConsoleApplication1.Models; using System.Data; using System.Data.Entity; using System.Data.SqlClient; class Program { static void Main(string[] args) { Database.SetInitializer(new DropCreateDatabaseAlways<DemoContext>()); using (DemoContext db = new DemoContext()) { db.Database.Initialize(false); int colA = 123; string colB = "abc"; // 使用佔位符號 db.Database.SqlQuery<TableName>("SELECT * FROM TableName WHERE ColA={0} AND ColB={1}", colA, colB); // 使用固定名稱的參數 db.Database.SqlQuery<TableName>("SELECT * FROM TableName WHERE ColA=@P0 AND ColB=@P1", colA, colB); // 使用SQL參數 db.Database.SqlQuery<TableName>( "SELECT * FROM TableName WHERE ColA=@ColA AND ColB=@ColB", new SqlParameter("ColA", colA), new SqlParameter("ColB", colB)); // 使用SQL參數並明確指定資料形態 db.

先建一張資料表，並加上幾個Attribute當例子 namespace ConsoleApplication1.Models { using System; using System.ComponentModel.DataAnnotations; using System.ComponentModel.DataAnnotations.Schema; [Table("Table1")] public class Table1 { [Key] public int Table1Id { get; set; } [Required] [StringLength(10, MinimumLength = 2)] public string C1 { get; set; } [Range(10, 20)] public int C2 { get; set; } public DateTime D1 { get; set; } public DateTime D2 { get; set; } } } 針對屬性驗證 namespace ConsoleApplication1 { using ConsoleApplication1.Models; using System; using System.

DbSet有一個Local，是用來存放從資料庫中取得的資料 namespace ConsoleApplication1 { using ConsoleApplication1.Models; using System; using System.Data.Entity; class Program { static void Main(string[] args) { // 初始化資料庫 Database.SetInitializer(new MyInit()); using (DemoContext db = new DemoContext()) { db.Database.Initialize(false); Console.WriteLine(db.Topic.Local.Count); db.Topic.Load(); Console.WriteLine(db.Topic.Local.Count); } } } } [](http://2.bp.blogspot.com/-nFIf_sip55A/VJFaB_gYo0I/AAAAAAAABzs/FxfhAybwr8Q/s1600/01.png) Local屬性是一個ObservableCollection，可以透過CollectionChanged事件來得到Local集合中發生變化的通知 namespace ConsoleApplication1 { using ConsoleApplication1.Models; using System; using System.Data.Entity; class Program { static void Main(string[] args) { // 初始化資料庫 Database.SetInitializer(new MyInit()); using (DemoContext db = new DemoContext()) { db.Database.Initialize(false); db.

用一個留言版的主表和明細表當例子，順便加入初始化資料來方便觀察資料載入方式的差異 DemoContext namespace ConsoleApplication1.Models { using System.Data.Entity; public class DemoContext : DbContext { public DbSet<Topic> Topic { get; set; } public DbSet<Reply> Reply { get; set; } } } 留言版主表 namespace ConsoleApplication1.Models { using System.Collections.Generic; using System.ComponentModel.DataAnnotations; using System.ComponentModel.DataAnnotations.Schema; [Table("Topic")] public class Topic { [Key] public int TopicId { get; set; } public string TopicTitle { get; set; } public virtual ICollection<Reply> Reply { get; set; } } }

首先建立一個留言版的資料庫來當例子 DemoContext namespace ConsoleApplication1.Models { using System.Data.Entity; public class DemoContext : DbContext { public DbSet<Topic> Topic { get; set; } public DbSet<Reply> Reply { get; set; } } } 留言版主表 namespace ConsoleApplication1.Models { using System.Collections.Generic; using System.ComponentModel.DataAnnotations; using System.ComponentModel.DataAnnotations.Schema; [Table("Topic")] public class Topic { [Key] public int TopicId { get; set; } public string TopicTitle { get; set; } public virtual ICollection<Reply> Reply { get; set; } } }

[Code First] 1. Entity Framework Code First 預設對應規則 2. Entity Framework Code First 對應規則設定 3. Entity Framework Code First 組織Fluent API 設定 4. Entity Framework Code First 資料庫初始化設定 5. Entity Framework Code First 一對一關聯設定 6. Entity Framework Code First 一對多關聯設定 7. Entity Framework Code First 多對多關聯設定 8. Entity Framework Code First Complex Type 9. Entity Framework Code First 繼承對應設定 [DbContext] 1. Entity Framework DbContext 新增、修改、刪除、查詢 2. Entity Framework DbContext 延遲加載、貪婪加載、顯性加載