Entity framework 6.0 簡明教程 ef6

http://www.entityframeworktutorial.net/code-first/entity-framework-code-first.aspx

Ef好的教程

 

 

Entity Framework的樂觀並發

http://www.cnblogs.com/Gyoung/archive/2013/01/18/2866649.html

附件:EntityFramework系列：MySql的RowVersion

 

EF里一對一、一對多、多對多關系的配置和級聯刪除

 

EntityFramework系列：Repository模式與單元測試

 

 

1. Nuget安裝好EF6.0.

2. 定義IDbContext , 定義context並實現

/// 
    /// 提供對象列表的一切操作接口
    /// 
    public interface IDbContext : IDisposable
    {
        Database Database { get; }
        /// 
        /// Get DbSet
        /// 
        /// Entity type
        /// DbSet
        IDbSet Set() where TEntity : BaseEntity;

        /// 
        /// Save changes
        /// 
        /// 
        int SaveChanges();

/// <summary>
    /// 繼承自DbContext, IDbContext,
    /// 為什么IDbContext接口里面的屬性和方法, 全部在DbContext里面有實現, 因此這里不需要做實現
    /// </summary>
    public class NopObjectContext : DbContext, IDbContext
    {
        public NopObjectContext()
            : base("name=DefaultConnection")
        {
            //超時時常
            ((IObjectContextAdapter)this).ObjectContext.CommandTimeout = 180;
            //這句代碼指定我們是自己手動生成數據庫
            //Database.SetInitializer<XEngineContext>(null);
        }
        /// <summary>
        /// 覆蓋DbContext里面的Set屬性, 主要是為了自定義的BaseEntity.
        /// </summary>
        /// <typeparam name="TEntity">Entity type</typeparam>
        /// <returns>DbSet</returns>
        public new IDbSet<TEntity> Set<TEntity>() where TEntity : BaseEntity
        {
            return base.Set<TEntity>();
        }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            //來自Nopcommerce里的動態加載所有的fluent api映射 dynamically load all configuration
            //System.Type configType = typeof(LanguageMap);   //any of your configuration classes here
            //var typesToRegister = Assembly.GetAssembly(configType).GetTypes()
            modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();//去掉ef自建表的時候命名帶復數
            modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
            //全局刪掉級聯刪除, 因為不常用.移除這個默認約定，再在需要開啟級聯刪除的FluentAPI關系映射中用. WillCascadeOnDelete(true) 單獨開啟

            var typesToRegister = Assembly.GetExecutingAssembly().GetTypes()
            .Where(type => !String.IsNullOrEmpty(type.Namespace))
            .Where(type => type.BaseType != null && type.BaseType.IsGenericType && type.BaseType.GetGenericTypeDefinition() == typeof(EntityTypeConfiguration<>));
            foreach (var type in typesToRegister)
            {
                dynamic configurationInstance = Activator.CreateInstance(type);
                modelBuilder.Configurations.Add(configurationInstance);
            };


            base.OnModelCreating(modelBuilder);
        }

 

下面來一個多對多的配置

下面是映射的map

 

如果用的聯合主鍵的話.

這里的主鍵數量必須和表的主鍵數量相同

public class Student
    {
        
        public int ID { get; set; }
        public string Name { get; set; }
        
        public int SiteID { get; set; }

        public virtual ICollection Courses{get;set;}
    }

    public class Course{
        public int ID{get;set;}
        public string Name { get; set; }
        
        public int SiteID { get; set; }

        public virtual ICollection Students { get; set; }
    }
    public class SCContext : DbContext
    {
        public SCContext()
            : base("name=DefaultConnection")
        {
            Database.SetInitializer(null);
        }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            //dynamically load all configuration
            //System.Type configType = typeof(LanguageMap);   //any of your configuration classes here
            //var typesToRegister = Assembly.GetAssembly(configType).GetTypes()
            modelBuilder.Conventions.Remove();

            modelBuilder.Entity().ToTable("Student").HasKey(x => new { x.ID, x.SiteID })
                .Property(x => x.ID).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

            modelBuilder.Entity().ToTable("Course").HasKey(x => new { x.ID, x.SiteID })
                .Property(x => x.ID).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
            //modelBuilder.Entity().Property(x => x.Name);

            modelBuilder.Entity().HasMany(x => x.Courses)
                .WithMany(x => x.Students)
                .Map(r =>
                {
                    r.ToTable("Student_Course_Mapping");
                    r.MapLeftKey(new string[]{"StudentID", "StudentSiteID"});
                    r.MapRightKey(new string[] { "CourseID", "CourseSiteID" });
                });

            base.OnModelCreating(modelBuilder);
        }
    }

下面是一對一

同樣在UserAccount里增加	UserExt依賴於UserAccount

 

最后是一對多

在UserAccount里增加

寫在UserAddressMap里. 這個表里有外鍵, 依賴於UserAccount.

 

最后來一發表結構