C#简单构架之EF进行读写分离+多数据库(Mysql/SqlService)

最近由于项目须要，研究了下EF的读写分离，因此作了一个demo进行测试，下面是项目的结构

表现层view

  主要提供Web、WebApi等表现层的解决方案

公共层public

   主要提供项目公共类库，数据缓存基础方法等

实体层model

   主要提供数据库映射模型，还有就是DDD领域操做模型

数据层Db

   主要封装EF操做基础类

数据服务层Service

   主要提供数据库操做服务、缓存操做服务

数据接口服务层inface

   主要提供数据库操做服务接口、缓存操做服务接口

1.首先是多数据库的支持，目前就支持mysql/sqlservice，若是须要添加更多的数据库支持，只须要再数据库操做类型上面添加便可

/// <summary>
    /// 数据库类型
    /// </summary>
    public enum DbContextType : byte
    {
        SqlService = 1,
        MySql = 2
    }

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分别对mysql/sqlservice的上下文操做进行封装

/// <summary>
    /// MySql操做类
    /// </summary>
    [DbConfigurationType(typeof(MySqlEFConfiguration))]
    public class MySqlContext : DbContext
    {
        public DbSet<Test> TestEntities { get; set; }
        /// <summary>
        /// 配置默认的字符串连接
        /// </summary>
        public MySqlContext() : base("DefaultConnection") {
        }
        /// <summary>
        /// 自定义数据库连接
        /// </summary>
        /// <param name="connenction"></param>
        public MySqlContext(string connenction) : base(connenction) { }
        /// <summary>
        /// 实体对应规则的映射配置
        /// </summary>
        /// <param name="modelBuilder"></param>
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
        }
    }

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/// <summary>
    /// Sql数据库操做类
    /// </summary>
    public class SqlServiceContext : DbContext
    {
        /// <summary>
        /// 配置默认的字符串连接
        /// </summary>
        public SqlServiceContext() {
        }
        /// <summary>
        /// 自定义数据库连接
        /// </summary>
        /// <param name="connenction"></param>
        public SqlServiceContext(string connenction) : base(connenction) {
        }
        /// <summary>
        /// 实体对应规则的映射配置
        /// </summary>
        /// <param name="modelBuilder"></param>
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
        }
    }

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在view调用时候，进行ef上下文初始化只须要设置类型

 /// <summary>
    /// 数据库策略初始化类
    /// </summary>
    public static class DBInitializer
    {
        public static DbContextType DbContextType { get; set; }
        /// <summary>
        /// 数据库初始化策略配置
        /// </summary>`
        public static void Initialize(DbContextType ContextType)
        {
            string IsUsedWR = System.Configuration.ConfigurationManager.AppSettings["IsUsedWR"];
            DbContextType = ContextType;
            ///得到数据库最后一个版本
            //   Database.SetInitializer<DBContextHelper>(new MigrateDatabaseToLatestVersion<DBContextHelper, DBConfiguration>());
            if (ContextType == DbContextType.SqlService)
            {
                Database.SetInitializer(new MigrateDatabaseToLatestVersion<WriteSqlServiceContext, WriteSqlServiceDBConfiguration>());
                if (IsUsedWR == "1") {
                    Database.SetInitializer(new MigrateDatabaseToLatestVersion<ReadSqlServiceContext, ReadSqlSqlServiceDBConfiguration>());
                }
                else
                {
                    Database.SetInitializer<ReadSqlServiceContext>(null);
                }
            }
            else
            {
                Database.SetInitializer(new MigrateDatabaseToLatestVersion<WriteMySqlContext, WriteMySqlDBConfiguration>());
                if (IsUsedWR == "1")
                {
                    Database.SetInitializer(new MigrateDatabaseToLatestVersion<ReadMySqlContext, ReadMySqlDBConfiguration>());
                }
                else
                {
                    Database.SetInitializer<ReadMySqlContext>(null);
                }                
                //Database.SetInitializer<WriteMySqlContext>(null);
               // Database.SetInitializer<ReadMySqlContext>(null);
            }
            // Database.SetInitializer<DBContextHelper>(null);
            ///删除原来数据库 从新建立数据库
            //Database.SetInitializer(new DropCreateDatabaseIfModelChanges<ContextHelper>());
            // Database.SetInitializer<ContextHelper>(new DropCreateDatabaseIfModelChanges<ContextHelper>());
        }
    }

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public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);

            //Autofac
            //ContainerBuilder builder = new ContainerBuilder();
            //builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly());
            //IContainer container = builder.Build();
            //DependencyResolver.SetResolver(new AutofacDependencyResolver(container));


            //Autofac初始化过程
            ContainerBuilder builder = new ContainerBuilder();
            builder.RegisterControllers(System.Reflection.Assembly.GetExecutingAssembly());//注册mvc容器的实现  
            var assemblys = BuildManager.GetReferencedAssemblies().Cast<Assembly>().ToList();
            builder.RegisterAssemblyTypes(assemblys.ToArray()).Where(t => t.Name.Contains("Service")).AsImplementedInterfaces();
            var container = builder.Build();
            DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
            //初始化数据库
            DBInitializer.Initialize(DbContextType.MySql);
        }
    }

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经过上面多数据库的支持已经完成，下面进行读写分离，分别进行继承上述上下文操做

/// <summary>
    /// 读
    /// </summary>
    public class WriteSqlServiceContext : SqlServiceContext
    {
        public WriteSqlServiceContext() : base("") { }
    }
    /// <summary>
    /// 写
    /// </summary>
    public class ReadSqlServiceContext : SqlServiceContext
    {
        public ReadSqlServiceContext() : base("") { }
    }

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经过工厂类进行初始化

/// <summary>
    /// 上下文工厂类
    /// </summary>
    public static class Contextfactory
    {
        /// <summary>
        /// 获取上下文
        /// </summary>
        /// <returns></returns>
        public  static DbContext GetContext(DbOpertionType OpertionType)
        {
            DbContextType ContextType = DBInitializer.DbContextType;
            if (ContextType == DbContextType.MySql)
            {
                if (OpertionType == DbOpertionType.Read)
                    return new ReadMySqlContext();
                else
                    return new WriteMySqlContext();
            }
            else
            {
                if (OpertionType == DbOpertionType.Read)
                    return new ReadSqlServiceContext();
                else
                    return new WriteSqlServiceContext();
            }
        }
        /// <summary>
        /// 获取上下文操做
        /// </summary>
        /// <typeparam name="TEntity"></typeparam>
        /// <param name="OpertionType"></param>
        /// <returns></returns>
        public static TEntity CallContext<TEntity>(DbOpertionType OpertionType) where TEntity: DbContext
        {
            var DbContext = GetContext(OpertionType);
            return (TEntity)DbContext;
        }
    }

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最后配置webcofig便可

 <!--数据库配置(WriteMySqlConnection:读数据库，ReadMySqlConnection：写数据库   若是无须要进行 就配置IsUsedWR，2个连接都写写入库)-->
  <connectionStrings>
    <add name="WriteMySqlConnection" connectionString="data source=*; Initial Catalog=YK_Test_WriteDB ; uid=root; pwd=yk12345;Charset=utf8" providerName="MySql.Data.MySqlClient" />   
    <add name="ReadMySqlConnection" connectionString="data source=*; Initial Catalog=YK_Test_ReadDB ; uid=root; pwd=yk12345;Charset=utf8" providerName="MySql.Data.MySqlClient" />
  </connectionStrings>
<!--数据库读取分离配置-->
    <!--是否开启读写分离  1：开启  0：不开启-->
    <add key="IsUsedWR" value="1"/>

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最后进行测试

public class TestController : Controller
    {
        private ITestService _TestServiceDb { get; set; }

        public TestController(ITestService TestServiceDb) {
            _TestServiceDb = TestServiceDb;
        }
        // GET: Test
        public ActionResult Index()
        {
            var result = _TestServiceDb.AddEntity(new Test() { ID=Guid.NewGuid(), Age=11, CreateTime=DateTime.Now, Name="Test" });
            var NewResult = _TestServiceDb.GetEntityByID(result.ID);
            return View();
        }
    }

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搞定，可能在代码上有点累赘，可是总算是可行的。

若是有兴趣的朋友能够留下邮箱，而后发全代码一块儿研究，谢谢！