Entity framework 6.0 简明教程 ef6

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

Ef好的教程

 

 

Entity Framework的乐观并发

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

附件:EntityFramework系列：MySql的RowVersion

 

EF里一对一、一对多、多对多关系的配置和级联删除

 

EntityFramework系列：Repository模式与单元测试

 

 

1. Nuget安装好EF6.0.

2. 定义IDbContext , 定义context并实现

/// 
    /// 提供对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>
    /// 继承自DbContext, IDbContext,
    /// 为什么IDbContext接口里面的属性和方法, 全部在DbContext里面有实现, 因此这里不需要做实现
    /// </summary>
    public class NopObjectContext : DbContext, IDbContext
    {
        public NopObjectContext()
            : base("name=DefaultConnection")
        {
            //超时时常
            ((IObjectContextAdapter)this).ObjectContext.CommandTimeout = 180;
            //这句代码指定我们是自己手动生成数据库
            //Database.SetInitializer<XEngineContext>(null);
        }
        /// <summary>
        /// 覆盖DbContext里面的Set属性, 主要是为了自定义的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)
        {
            //来自Nopcommerce里的动态加载所有的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自建表的时候命名带复数
            modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
            //全局删掉级联删除, 因为不常用.移除这个默认约定，再在需要开启级联删除的FluentAPI关系映射中用. WillCascadeOnDelete(true) 单独开启

            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);
        }

 

下面来一个多对多的配置

下面是映射的map

 

如果用的联合主键的话.

这里的主键数量必须和表的主键数量相同

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);
        }
    }

下面是一对一

同样在UserAccount里增加	UserExt依赖于UserAccount

 

最后是一对多

在UserAccount里增加

写在UserAddressMap里. 这个表里有外键, 依赖于UserAccount.

 

最后来一发表结构