引言
在网上很少看到有关于系统讲解EFCore源码的,可能大概也许是因为EFCore的源码总体是没有asp.net web的源码流程清晰,正如群友所说,EFCore的源码大致看起来有点凌乱,与其说凌乱,不如说是没有一个好的方向;然后昨天在群里有一个朋友再说,EfCore的拦截器如何注入Web的服务,以及EfCore如何自定义查询,我就看了一下EfCore的源码,在此之前我针对asp.net web 做了一个源码解读,有兴趣的朋友可以看前面的文章,也给别人说过啥时候讲解一下efcore的源码,刚好借助这么一个机会,讲一讲EfCore的源码,本篇文章作为一个开端,会呈现一下几点
一:首先是AddDbContext里面做了什么。
二:DbContext的构造函数里面做了那些事情。
三:如何在EfCore的服务中获取到Web注入的服务的方式之一。
四:拦截查询的几种方式。
五:使用缓存查询方法提升性能。
六:如何托管EFCORE的IOC容器(和Web的IOC使用同一个)
以上作为本篇文章的所有内容,接下来,我们来开始讲解源码,动手实践。
AddDbContext
EfCore提供了AddDbContext,AddDbContextFactory,AddDbContextPool,AddPooledDbContextFactory这几种扩展方法,我们会依次讲解,首先会讲解AddDbContext,后续的文章会依次讲解其余的方法。话不多说,上源码。下面是AddDbContext的源码,提供了多种方法,但是最终都会调用到这里,第一个参数是一个设置OptionBuilder的委托,传入了ServiceProvider和OptionBuilder,第二,三个分别是DbContext和DBContextOption的生命周期。
在下面的代码,刚开始判断了如果DBContext的生命周期是单例,要将Option的生命周期也设置为单例,如果不设置为单例,就会出现错误,这个错误在之前讲解IOC的文章中,我记得也提到过,接下来判断设置Option的委托是否为null,如果不为null,那DBContext的构造函数是必须要有一个参数,所以下面调用了一个方法CheckContextConstructors。
- public static IServiceCollection AddDbContext<TContextService, TContextImplementation>(
- this IServiceCollection serviceCollection,
- Action<IServiceProvider, DbContextOptionsBuilder>? optionsAction,
- ServiceLifetime contextLifetime = ServiceLifetime.Scoped,
- ServiceLifetime optionsLifetime = ServiceLifetime.Scoped)
- where TContextImplementation : DbContext, TContextService
- {
- if (contextLifetime == ServiceLifetime.Singleton)
- {
- optionsLifetime = ServiceLifetime.Singleton;
- }
- if (optionsAction != null)
- {
- CheckContextConstructors<TContextImplementation>();
- }
- AddCoreServices<TContextImplementation>(serviceCollection, optionsAction, optionsLifetime);
- if (serviceCollection.Any(d => d.ServiceType == typeof(IDbContextFactorySource<TContextImplementation>)))
- {
- // Override registration made by AddDbContextFactory
- var serviceDescriptor = serviceCollection.FirstOrDefault(d => d.ServiceType == typeof(TContextImplementation));
- if (serviceDescriptor != null)
- {
- serviceCollection.Remove(serviceDescriptor);
- }
- }
- serviceCollection.TryAdd(new ServiceDescriptor(typeof(TContextService), typeof(TContextImplementation), contextLifetime));
- if (typeof(TContextService) != typeof(TContextImplementation))
- {
- serviceCollection.TryAdd(
- new ServiceDescriptor(
- typeof(TContextImplementation),
- p => (TContextImplementation)p.GetService<TContextService>()!,
- contextLifetime));
- }
- return serviceCollection;
- }
- private static void CheckContextConstructors<TContext>()
- where TContext : DbContext
- {
- var declaredConstructors = typeof(TContext).GetTypeInfo().DeclaredConstructors.ToList();
- if (declaredConstructors.Count == 1
- && declaredConstructors[0].GetParameters().Length == 0)
- {
- throw new ArgumentException(CoreStrings.DbContextMissingConstructor(typeof(TContext).ShortDisplayName()));
- }
- }
在CheckContextConstructors,我们看到反射去获取DBContext的继承类,查找构造函数,并且参数如果是0就会报异常。接下来在往下走,调用了一个AddCoreServices的方法,在这个方法里,我们是将DBContextOptions的泛型和非泛型注入到容器里面去,其中有一个CreateDbContextOptions的方法,里面去new了一个DbContextOptionsBuilder类,然后调用了一个UseApplicationServiceProvider方法,
- private static void AddCoreServices<TContextImplementation>(
- IServiceCollection serviceCollection,
- Action<IServiceProvider, DbContextOptionsBuilder>? optionsAction,
- ServiceLifetime optionsLifetime)
- where TContextImplementation : DbContext
- {
- serviceCollection.TryAdd(
- new ServiceDescriptor(
- typeof(DbContextOptions<TContextImplementation>),
- p => CreateDbContextOptions<TContextImplementation>(p, optionsAction),
- optionsLifetime));
- serviceCollection.Add(
- new ServiceDescriptor(
- typeof(DbContextOptions),
- p => p.GetRequiredService<DbContextOptions<TContextImplementation>>(),
- optionsLifetime));
- }
- private static DbContextOptions<TContext> CreateDbContextOptions<TContext>(
- IServiceProvider applicationServiceProvider,
- Action<IServiceProvider, DbContextOptionsBuilder>? optionsAction)
- where TContext : DbContext
- {
- var builder = new DbContextOptionsBuilder<TContext>(
- new DbContextOptions<TContext>(new Dictionary<Type, IDbContextOptionsExtension>()));
- builder.UseApplicationServiceProvider(applicationServiceProvider);
- optionsAction?.Invoke(applicationServiceProvider, builder);
- return builder.Options;
- }
下面是一个UseApplicationServiceProvider的调用链,最终调用到了WithApplicationServiceProvider方法,可以看到是返回了一个CoreOptionsExtension,最终调用WithOptions添加到了DbContextOptionsBuilder里面去,上面的代码中,我们new了一个DbContextOptionsBuilder,里面传入了一个DbContextOptions,构造函数传入了new Dictionary<Type,IDbContextOptionsExtension>(),最终我们的CoreOptionsExtension会添加到我们传入的这个字典里,用来保存所有的IDbContextOptionsExtension,这个接口可以理解为,数据库Options的扩展,接口定义如下,Info是关于扩展的一些元数据信息,ApplyService方法,参数是一个IServiceCollection,这个方法是我们将我们要注入的服务注入到这个里面去,因为EfCore的IOC和Web的IOC是区分开的,所以使用了不同的IServiceCollection,虽然提供了UseApplicationServiceProvider和UseInternalServiceProvider方法,实际上并不能实现IOC接管,设计实在是鸡肋,待会到了DbContext的构造函数中我们会看到为什么说鸡肋。Validate方法则是验证当前扩展,例如你得这个实现里面有一些参数,是必须要配置,或者配置有一个规则,我们在这里验证我们的配置或者规则是否符合我们需要的数据,如果不符合,在这里可以直接抛出异常。
回到CreateDbContextOptions,此时我们可以确保我们的Option的Extension里面是有一个CoreOptionsExtension,接下来,判断有没有设置OptionsBuilder的委托,调用然后返回到AddDbContext。
- public new virtual DbContextOptionsBuilder<TContext> UseApplicationServiceProvider(IServiceProvider? serviceProvider)
- => (DbContextOptionsBuilder<TContext>)base.UseApplicationServiceProvider(serviceProvider);
- public virtual DbContextOptionsBuilder UseApplicationServiceProvider(IServiceProvider? serviceProvider)
- => WithOption(e => e.WithApplicationServiceProvider(serviceProvider));
- public virtual CoreOptionsExtension WithApplicationServiceProvider(IServiceProvider? applicationServiceProvider)
- {
- var clone = Clone();
- clone._applicationServiceProvider = applicationServiceProvider;
- return clone;
- }
- private DbContextOptionsBuilder WithOption(Func<CoreOptionsExtension, CoreOptionsExtension> withFunc)
- {
- ((IDbContextOptionsBuilderInfrastructure)this).AddOrUpdateExtension(
- withFunc(Options.FindExtension<CoreOptionsExtension>() ?? new CoreOptionsExtension()));
- return this;
- }
- public interface IDbContextOptionsExtension
- {
- /// <summary>
- /// Information/metadata about the extension.
- /// </summary>
- DbContextOptionsExtensionInfo Info { get; }
- /// <summary>
- /// Adds the services required to make the selected options work. This is used when there
- /// is no external <see cref="IServiceProvider" /> and EF is maintaining its own service
- /// provider internally. This allows database providers (and other extensions) to register their
- /// required services when EF is creating an service provider.
- /// </summary>
- /// <param name="services">The collection to add services to.</param>
- void ApplyServices(IServiceCollection services);
- /// <summary>
- /// Gives the extension a chance to validate that all options in the extension are valid.
- /// Most extensions do not have invalid combinations and so this will be a no-op.
- /// If options are invalid, then an exception should be thrown.
- /// </summary>
- /// <param name="options">The options being validated.</param>
- void Validate(IDbContextOptions options);
- }
- void IDbContextOptionsBuilderInfrastructure.AddOrUpdateExtension<TExtension>(TExtension extension)
- => _options = _options.WithExtension(extension);
在AddDbContext的最后,这几行代码,是将我们的DbContext注入到我们的IOC容器中去。
- if (serviceCollection.Any(d => d.ServiceType == typeof(IDbContextFactorySource<TContextImplementation>)))
- {
- // Override registration made by AddDbContextFactory
- var serviceDescriptor = serviceCollection.FirstOrDefault(d => d.ServiceType == typeof(TContextImplementation));
- if (serviceDescriptor != null)
- {
- serviceCollection.Remove(serviceDescriptor);
- }
- }
- serviceCollection.TryAdd(new ServiceDescriptor(typeof(TContextService), typeof(TContextImplementation), contextLifetime));
- if (typeof(TContextService) != typeof(TContextImplementation))
- {
- serviceCollection.TryAdd(
- new ServiceDescriptor(
- typeof(TContextImplementation),
- p => (TContextImplementation)p.GetService<TContextService>()!,
- contextLifetime));
- }
至此,关于AddDbContext的源码讲解完毕,接下来进到DbContext构造函数的源码讲解,这里设计内容稍微多一些。
DBContext构造
构造函数的代码是整体是没多少的,但是最重要的还是在于GetOrAdd的方法。所以这里我会只讲这个方法的内部
- public DbContext(DbContextOptions options)
- {
- Check.NotNull(options, nameof(options));
- if (!options.ContextType.IsAssignableFrom(GetType()))
- {
- throw new InvalidOperationException(CoreStrings.NonGenericOptions(GetType().ShortDisplayName()));
- }
- _options = options;
- // This service is not stored in _setInitializer as this may not be the service provider that will be used
- // as the internal service provider going forward, because at this time OnConfiguring has not yet been called.
- // Mostly that isn't a problem because set initialization is done by our internal services, but in the case
- // where some of those services are replaced, this could initialize set using non-replaced services.
- // In this rare case if this is a problem for the app, then the app can just not use this mechanism to create
- // DbSet instances, and this code becomes a no-op. However, if this set initializer is then saved and used later
- // for the Set method, then it makes the problem bigger because now an app is using the non-replaced services
- // even when it doesn't need to.
- ServiceProviderCache.Instance.GetOrAdd(options, providerRequired: false)
- .GetRequiredService<IDbSetInitializer>()
- .InitializeSets(this);
- EntityFrameworkEventSource.Log.DbContextInitializing();
- }
下面是ServiceProviderCache的全部源码,在GetOrAdd方法,先获取了CoreOptionsExtension,这个我们在AddDbContext的时候,已经添加过了,并且设置了ApplicationProvider,在往下走,判断InternalServiceProvider,这里我们没有设置,就会继续往下走,判断了一个ServiceProviderCachingEnabled 这个默认是true,然后下面获取CoreOptionsExtension的ApplicationServiceProvider,还记得我们在最初的时候AddDbContext的时候,创建DbContextOptionsBuilder的时候,我们UseApplicationServiceProvider方法,就是设置了一个公用的Provider,现在把他在设置为null,如果说这个Provider有啥作用,哈哈哈哈,我认为他就是创建Options的时候需要用,然后给一个有东西的不为空的CoreOptionsExtension,这个方法,实际上我觉得微软设置为internal最好了,这样可能会存在误解开发者,而InternalServiceProvider是很有用,可以和我们的web共用一个ioc容器,在本文的最后,我会将ef的ioc容器托管到web的。
ServiceProviderCachingEnabled参数代表是否将GetOrAdd通过BuildServiceProvider创建的ServiceProvider缓存到_configuration中去,不缓存的话,每次都是一个新的Provider,对性能有影响,如果缓存,则第一次创建后面都是从那里面取。
接下来就到了GetOrAdd最后,要调用BuildServiceProvider方法来创建一个ServiceProvider,下面的方法,我们着重看几个关键点一个是ApplyService,一个是new ServiceCollection(说明web的ioc和ef的ioc不是同一个),ReplaceService。
- public class ServiceProviderCache
- {
- private readonly ConcurrentDictionary<IDbContextOptions, (IServiceProvider ServiceProvider, IDictionary<string, string> DebugInfo)>
- _configurations = new();
- /// <summary>
- /// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
- /// the same compatibility standards as public APIs. It may be changed or removed without notice in
- /// any release. You should only use it directly in your code with extreme caution and knowing that
- /// doing so can result in application failures when updating to a new Entity Framework Core release.
- /// </summary>
- public static ServiceProviderCache Instance { get; } = new();
- /// <summary>
- /// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
- /// the same compatibility standards as public APIs. It may be changed or removed without notice in
- /// any release. You should only use it directly in your code with extreme caution and knowing that
- /// doing so can result in application failures when updating to a new Entity Framework Core release.
- /// </summary>
- public virtual IServiceProvider GetOrAdd(IDbContextOptions options, bool providerRequired)
- {
- var coreOptionsExtension = options.FindExtension<CoreOptionsExtension>();
- var internalServiceProvider = coreOptionsExtension?.InternalServiceProvider;
- if (internalServiceProvider != null)
- {
- ValidateOptions(options);
- var optionsInitializer = internalServiceProvider.GetService<ISingletonOptionsInitializer>();
- if (optionsInitializer == null)
- {
- throw new InvalidOperationException(CoreStrings.NoEfServices);
- }
- if (providerRequired)
- {
- optionsInitializer.EnsureInitialized(internalServiceProvider, options);
- }
- return internalServiceProvider;
- }
- if (coreOptionsExtension?.ServiceProviderCachingEnabled == false)
- {
- return BuildServiceProvider(options, (_configurations, options)).ServiceProvider;
- }
- var cacheKey = options;
- var extension = options.FindExtension<CoreOptionsExtension>();
- if (extension?.ApplicationServiceProvider != null)
- {
- cacheKey = ((DbContextOptions)options).WithExtension(extension.WithApplicationServiceProvider(null));
- }
- return _configurations.GetOrAdd(
- cacheKey,
- static (contextOptions, tuples) => BuildServiceProvider(contextOptions, tuples), (_configurations, options))
- .ServiceProvider;
- static (IServiceProvider ServiceProvider, IDictionary<string, string> DebugInfo) BuildServiceProvider(
- IDbContextOptions _,
- (ConcurrentDictionary<IDbContextOptions, (IServiceProvider ServiceProvider, IDictionary<string, string> DebugInfo)>,
- IDbContextOptions) arguments)
- {
- var (configurations, options) = arguments;
- ValidateOptions(options);
- var debugInfo = new Dictionary<string, string>();
- foreach (var optionsExtension in options.Extensions)
- {
- optionsExtension.Info.PopulateDebugInfo(debugInfo);
- }
- debugInfo = debugInfo.OrderBy(_ => debugInfo.Keys).ToDictionary(d => d.Key, v => v.Value);
- var services = new ServiceCollection();
- var hasProvider = ApplyServices(options, services);
- var replacedServices = options.FindExtension<CoreOptionsExtension>()?.ReplacedServices;
- if (replacedServices != null)
- {
- var updatedServices = new ServiceCollection();
- foreach (var descriptor in services)
- {
- if (replacedServices.TryGetValue((descriptor.ServiceType, descriptor.ImplementationType), out var replacementType))
- {
- ((IList<ServiceDescriptor>)updatedServices).Add(
- new ServiceDescriptor(descriptor.ServiceType, replacementType, descriptor.Lifetime));
- }
- else if (replacedServices.TryGetValue((descriptor.ServiceType, null), out replacementType))
- {
- ((IList<ServiceDescriptor>)updatedServices).Add(
- new ServiceDescriptor(descriptor.ServiceType, replacementType, descriptor.Lifetime));
- }
- else
- {
- ((IList<ServiceDescriptor>)updatedServices).Add(descriptor);
- }
- }
- services = updatedServices;
- }
- var serviceProvider = services.BuildServiceProvider();
- if (hasProvider)
- {
- serviceProvider
- .GetRequiredService<ISingletonOptionsInitializer>()
- .EnsureInitialized(serviceProvider, options);
- }
- using (var scope = serviceProvider.CreateScope())
- {
- var scopedProvider = scope.ServiceProvider;
- // If loggingDefinitions is null, then there is no provider yet
- var loggingDefinitions = scopedProvider.GetService<LoggingDefinitions>();
- if (loggingDefinitions != null)
- {
- // Because IDbContextOptions cannot yet be resolved from the internal provider
- var logger = new DiagnosticsLogger<DbLoggerCategory.Infrastructure>(
- ScopedLoggerFactory.Create(scopedProvider, options),
- scopedProvider.GetRequiredService<ILoggingOptions>(),
- scopedProvider.GetRequiredService<DiagnosticSource>(),
- loggingDefinitions,
- new NullDbContextLogger());
- if (configurations.IsEmpty)
- {
- logger.ServiceProviderCreated(serviceProvider);
- }
- else
- {
- logger.ServiceProviderDebugInfo(
- debugInfo,
- configurations.Values.Select(v => v.DebugInfo).ToList());
- if (configurations.Count >= 20)
- {
- logger.ManyServiceProvidersCreatedWarning(
- configurations.Values.Select(e => e.ServiceProvider).ToList());
- }
- }
- var applicationServiceProvider = options.FindExtension<CoreOptionsExtension>()?.ApplicationServiceProvider;
- if (applicationServiceProvider?.GetService<IRegisteredServices>() != null)
- {
- logger.RedundantAddServicesCallWarning(serviceProvider);
- }
- }
- }
- return (serviceProvider, debugInfo);
- }
- }
- private static void ValidateOptions(IDbContextOptions options)
- {
- foreach (var extension in options.Extensions)
- {
- extension.Validate(options);
- }
- }
- private static bool ApplyServices(IDbContextOptions options, ServiceCollection services)
- {
- var coreServicesAdded = false;
- foreach (var extension in options.Extensions)
- {
- extension.ApplyServices(services);
- if (extension.Info.IsDatabaseProvider)
- {
- coreServicesAdded = true;
- }
- }
- if (coreServicesAdded)
- {
- return true;
- }
- new EntityFrameworkServicesBuilder(services).TryAddCoreServices();
- return false;
- }
- }
我们先看ApplyService,在这个方法我们看到,是传入了Options,ServiceCollection,然后循环遍历Options的Extensions,调用他的ApplyService方法,传入serviceCollection,下图,我们看到默认是有这么多的实现,根据你在对DBContextOptionsBuilder提供的方法的使用,会给Options的Extensions添加不同的Extension,最后调用各自的ApplyService,我们找一个看看具体在做什么事情。哈哈,不用猜,大家也知道,肯定是注入服务,通过options的Extensions附加一些其他关于EF的功能,并且将他们所需要的服务注入到传入的ServiceCollection里面,其他的都是一样,所以在我们没有托管ef的ioc到web的时候可以使用这种方式来实现,后面也会写一个这样的例子。最后调用一下TryAddCoreService方法,这个方法有许多EF需用到重要的服务的注入。
而ReplaceService就是我们在调用DbContextOptionsBuilder的ReplaceService<>方法的时候里面保存的我们要替换的类型,以及实现,在这里重新注入到容器里,用上面的代码结合看,就是ApplyService先注入一遍,然后在替换一下,最后调用一下BuildServiceProvider方法生成一个ServiceProvider,在后面的代码就是一些日志相关的配置,此处就不过多讲解。
- public virtual void ApplyServices(IServiceCollection services)
- => services.AddEntityFrameworkProxies();


在上面的讲解中,我们有几个可以自定义的点就是一个是IDbContextOptionsExtension,这个我们可以在不托管ef的ioc到web的ioc的时候,我们可以实现一个这个接口,然后在代码添加到Extension就可以注入EF所需要用到的服务。接下来在下面段落,我会写一个简单的例子来注入我们要的服务。(不托管ioc到web的方式)。
EFCore服务注入
先上代码,代码没有多少,就是实现这个接口,定义一个Inject特性,用来标记从Web的IOC我们需要检索那些接口注入到EF的ioc中去,这样做有一个弊端就是Web的会注入一遍,Ef也会注入一遍,重复注入,在Program.cs里面我们先注入一个返回IServiceCollection的Func,这样在DBContext可以获取到这个 传到ServiceExtension里面,就可以拿到Web的IOC注入的服务。
- builder.Services.AddScoped<IWebGetName, WebGetName>();
- builder.Services.AddSingleton(() => builder.Services);
- [InjectAttribute]
- public interface IWebGetName
- {
- public string GetName();
- }
- [AttributeUsage(AttributeTargets.Interface| AttributeTargets.Class)]
- public class InjectAttribute:Attribute
- {
- public InjectAttribute()
- {
-
- }
- }
- public class ServiceExtension : IDbContextOptionsExtension
- {
- public ServiceExtension(Func<IServiceCollection> func)
- {
- Func = func;
- }
- public DbContextOptionsExtensionInfo Info => new ExtensionInfo(this);
- public Func<IServiceCollection> Func { get; }
- public void ApplyServices(IServiceCollection services)
- {
- var ser=Func();
- var type = ser.Where(s => s.ServiceType?.GetCustomAttribute<InjectAttribute>() != null || s.ImplementationType?.GetCustomAttribute<InjectAttribute>() != null).ToList();
- foreach (var item in type)
- {
- services.TryAdd(new ServiceDescriptor(item.ServiceType, item.ImplementationType, item.Lifetime));
- }
- services.AddScoped<IDBGetName, DBGetName>();
- }
- public void Validate(IDbContextOptions options)
- {
- }
- }
- public class ExtensionInfo: DbContextOptionsExtensionInfo
- {
- public ExtensionInfo(IDbContextOptionsExtension extension):base(extension)
- {
-
- }
- public override bool IsDatabaseProvider => false;
- public override string LogFragment => string.Empty;
- public override int GetServiceProviderHashCode()
- {
- return 0;
- }
- public override void PopulateDebugInfo(IDictionary<string, string> debugInfo)
- {
- }
- public override bool ShouldUseSameServiceProvider(DbContextOptionsExtensionInfo other)
- {
- return true;
- }
- }
接口定义好之后,服务也注入进去,接下来就是在DBContext里面添加这个扩展,因为optionsBuilder.Options只读,所以我们添加Extension就需要用AddOrUpdateExtension的方法来添加,因为Options在DbContextOptionsBuilder的内部字段是可以更改的。接下来扩展添加进去之后,我们运行程序,获取一个DBContext,然后就会走到这里添加我们的扩展,从而注入我们注入的IWebGetName,就可以在EF的IOC获取我们web注入服务。
- builder.Services.AddDbContext<DecodeMicroMsgContext>((a, m) => {
- ((IDbContextOptionsBuilderInfrastructure)m).AddOrUpdateExtension(new ServiceExtension(a.GetService<Func<IServiceCollection>>()));
- m.UseSqlite("Data Source=C:\\Users\\Chenxd\\Desktop\\资料\\CrackMsg\\CrackDb\\CrackDb\\bin\\Debug\\net7.0-windows\\TOOLS\\output\\decode_MicroMsg.db;");
- });
拦截查询
Sql拦截
针对SQL拦截,这里我会直接贴上我之前有一篇文章aop的代码,来作为讲解,其中有用到了DBInterceptor作为拦截器拦截DBCommand进行sql拦截,实现读写分离的方式,下面的代码是我自己实现了DBCommandInterceptor来实现的一个拦截器,在DBContext中将拦截器添加进去,在每次执行查询或者增加删除修改的时候,都会进入这个拦截器,从而实现自己想要的业务逻辑,我在此处是写了一个简单的读写分离,感兴趣的可以看看之前的文章https://www.cnblogs.com/1996-Chinese-Chen/p/15776120.html这个文章的代码地址已经失效,最后我会将本例程的所有代码放在百度网盘,其中包括这个AOP的代码,感兴趣的朋友可以下载看看。
- var list=new List<IInterceptor>();
- list.Add(new DbContextInterceptor());
- optionsBuilder.AddInterceptors(list);
- public class DbContextInterceptor:DbCommandInterceptor
- {
- private DbConnection _connection;
- private DbCommand _command;
- private CommandSource _commandSource;
- public DbContextInterceptor()
- {
- }
- public override DbCommand CommandCreated(CommandEndEventData eventData, DbCommand result)
- {
- return _command;
- }
- public override InterceptionResult<DbCommand> CommandCreating(CommandCorrelatedEventData eventData, InterceptionResult<DbCommand> result)
- {
- _commandSource = eventData.CommandSource;
- if (eventData.CommandSource==CommandSource.LinqQuery)
- {
- _connection = new MySqlConnection(eventData.Connection.ConnectionString);
- _command = new MySqlCommand();
- }
- return InterceptionResult<DbCommand>.SuppressWithResult(_command);
- }
- public override void CommandFailed(DbCommand command, CommandErrorEventData eventData)
- {
- base.CommandFailed(command, eventData);
- }
- public override Task CommandFailedAsync(DbCommand command, CommandErrorEventData eventData, CancellationToken cancellationToken = default)
- {
- return base.CommandFailedAsync(command, eventData, cancellationToken);
- }
- public override InterceptionResult DataReaderDisposing(DbCommand command, DataReaderDisposingEventData eventData, InterceptionResult result)
- {
- return base.DataReaderDisposing(command, eventData, result);
- }
- public override int NonQueryExecuted(DbCommand command, CommandExecutedEventData eventData, int result)
- {
- return base.NonQueryExecuted(command, eventData, result);
- }
- public override ValueTask<int> NonQueryExecutedAsync(DbCommand command, CommandExecutedEventData eventData, int result, CancellationToken cancellationToken = default)
- {
- return base.NonQueryExecutedAsync(command, eventData, result, cancellationToken);
- }
- public override InterceptionResult<int> NonQueryExecuting(DbCommand command, CommandEventData eventData, InterceptionResult<int> result)
- {
- return base.NonQueryExecuting(command, eventData, result);
- }
- public override ValueTask<InterceptionResult<int>> NonQueryExecutingAsync(DbCommand command, CommandEventData eventData, InterceptionResult<int> result, CancellationToken cancellationToken = default)
- {
- return base.NonQueryExecutingAsync(command, eventData, result, cancellationToken);
- }
- public override DbDataReader ReaderExecuted(DbCommand command, CommandExecutedEventData eventData, DbDataReader result)
- {
- return base.ReaderExecuted(command, eventData, result);
- }
- public override ValueTask<DbDataReader> ReaderExecutedAsync(DbCommand command, CommandExecutedEventData eventData, DbDataReader result, CancellationToken cancellationToken = default)
- {
- return base.ReaderExecutedAsync(command, eventData, result, cancellationToken);
- }
- public override InterceptionResult<DbDataReader> ReaderExecuting(DbCommand command, CommandEventData eventData, InterceptionResult<DbDataReader> result)
- {
- command.CommandText = "";
- return base.ReaderExecuting(command, eventData, result);
- }
- public async override ValueTask<InterceptionResult<DbDataReader>> ReaderExecutingAsync(DbCommand command, CommandEventData eventData, InterceptionResult<DbDataReader> result, CancellationToken cancellationToken = default)
- {
- InterceptionResult<DbDataReader> results;
- if (_commandSource == CommandSource.LinqQuery)
- {
- var connect = new MySqlConnection("data source=192.168.21.129;database=MasterSlave; userid=root;pwd=199645; charset=utf8;ConvertZeroDateTime=True;pooling=true; allowuservariables=true;");
- connect.Open();
- _command = new MySqlCommand(command.CommandText, connect);
- var reader = await _command.ExecuteReaderAsync();
- results = InterceptionResult<DbDataReader>.SuppressWithResult(reader);
- }
- else
- {
- results=await base.ReaderExecutingAsync(command, eventData, result, cancellationToken);
- }
- return results;
- }
- public override object ScalarExecuted(DbCommand command, CommandExecutedEventData eventData, object result)
- {
- return base.ScalarExecuted(command, eventData, result);
- }
- public override ValueTask<object> ScalarExecutedAsync(DbCommand command, CommandExecutedEventData eventData, object result, CancellationToken cancellationToken = default)
- {
- return base.ScalarExecutedAsync(command, eventData, result, cancellationToken);
- }
- public override InterceptionResult<object> ScalarExecuting(DbCommand command, CommandEventData eventData, InterceptionResult<object> result)
- {
- return base.ScalarExecuting(command, eventData, result);
- }
- public override ValueTask<InterceptionResult<object>> ScalarExecutingAsync(DbCommand command, CommandEventData eventData, InterceptionResult<object> result, CancellationToken cancellationToken = default)
- {
- return base.ScalarExecutingAsync(command, eventData, result, cancellationToken);
- }
- }
表达式拦截
上面我们讲了SQL拦截,接下来我们讲一下表达式拦截,我们都知道,EF的核心在于表达式树,可以说表达式树构造了整个EF的核心,关于表达式树,我在我的第一篇博客就写了很多关于表达式树的案例,https://www.cnblogs.com/1996-Chinese-Chen/p/14987967.html,感兴趣的朋友可以看看,所以此处表达式树我不会做讲解,只有如何实现自定义的表达式树拦截,
重要的有三个我们需要实现的接口,一个是IQueryable,IQueryCompiler,还有一个IAsyncQueryProvider,通过实现这三个接口,外加IDatabase,IQueryContextFactory需要用到的两个接口,实际上只是表达式拦截,只需要实现一个IQueryCompiler也可以实现,我i自己是实现了这三个,最主要的还是在IQueryCompiler,接下来看看具体的实现代码。
IQueryCompiler
- public class TestQueryCompiler : IQueryCompiler
- {
- public TestQueryCompiler(IDatabase database, IQueryContextFactory queryContextFactory)
- {
- Database = database;
- var a = Database.GetType();
- QueryContextFactory = queryContextFactory;
- }
- public IDatabase Database { get; }
- public IQueryContextFactory QueryContextFactory { get; }
- public Func<QueryContext, TResult> CreateCompiledAsyncQuery<TResult>(Expression query)
- {
- var queryFunc = Database.CompileQuery<TResult>(query, true);
- return queryFunc;
- }
- public Func<QueryContext, TResult> CreateCompiledQuery<TResult>(Expression query)
- {
- var queryFunc = Database.CompileQuery<TResult>(query, false);
- return queryFunc;
- }
- public TResult Execute<TResult>(Expression query)
- {
- var queryFunc = Database.CompileQuery<TResult>(query, false);
- var res = queryFunc(QueryContextFactory.Create());
- return res;
- }
- public TResult ExecuteAsync<TResult>(Expression query, CancellationToken cancellationToken)
- {
- var queryFunc = Database.CompileQuery<TResult>(query, true);
- var res = queryFunc(QueryContextFactory.Create());
- return res;
- }
- }
IAsyncQueryProvider
- public class TestQueryProvider : IAsyncQueryProvider
- {
- public TestQueryProvider(IDBGetName ta, IQueryCompiler query,IWebGetName webGetName)
- {
- Ta = ta;
- Query = query;
- WebGetName = webGetName;
- }
- public IDBGetName Ta { get; }
- public IQueryCompiler Query { get; }
- public IWebGetName WebGetName { get; }
- public IQueryable CreateQuery(Expression expression)
- {
- return new Queryable<object>(this, expression);
- }
- public IQueryable<TElement> CreateQuery<TElement>(Expression expression)
- {
- return new Queryable<TElement>(this, expression);
- }
- public object? Execute(Expression expression)
- {
- return Query.Execute<object>(expression);
- }
- public TResult Execute<TResult>(Expression expression)
- {
- return Query.Execute<TResult>(expression);
- }
- public TResult ExecuteAsync<TResult>(Expression expression, CancellationToken cancellationToken = default)
- {
- return Query.ExecuteAsync<TResult>(expression, cancellationToken);
- }
- }
IQueryable
- public class Queryable<T> : IQueryable<T>
- {
- public Queryable(IAsyncQueryProvider queryProvider, Expression expression)
- {
- QueryProvider = queryProvider;
- Expression = expression;
- }
- public Type ElementType => typeof(T);
- public IAsyncQueryProvider QueryProvider { get; }
- public Expression Expression { get; }
- public IQueryProvider Provider => QueryProvider;
- public IEnumerator GetEnumerator()
- {
- return Provider.Execute<IEnumerable>(Expression).GetEnumerator();
- }
- IEnumerator<T> IEnumerable<T>.GetEnumerator()
- {
- return Provider.Execute<IEnumerable<T>>(Expression).GetEnumerator();
- }
- }
在实现了那三个接口之后,我们就需要将我们的服务使用DBContextOptionsBuilder的ReplaceService替换掉,这样,在执行查询的时候就会走我们创建的TestQueryProvider,然后我们在这个类里调用关于Queryable和TestQueryCompiler来执行查询,如果又需要修改,也可以修改Expression从而达到拦截修改。我们最终是需要借助IDataBase的CompileQuery方法来实现构建查询的委托,从而实现查询,在底层还有Visitor遍历表达式树,当然了,此处我只展示一个拦截表达式树,后续的源码讲解会看到,欢迎大家关注。
如果是使用了EF的IOC托管到了Web的IOC,只需要正常注入服务就行,生命周期是Scope,
- #未接管
optionsBuilder.ReplaceService<IAsyncQueryProvider,TestQueryProvider >(); - optionsBuilder.ReplaceService<IQueryCompiler,TestQueryCompiler>();
#接管IOC
builder.Services.AddScoped<IAsyncQueryProvider, TestQueryProvider>();
builder.Services.AddScoped<IQueryCompiler, TestQueryCompiler>(s =>
{
var database = s.GetService<IDatabase>();
var factory = s.GetService<IQueryContextFactory>();
return new TestQueryCompiler(database, factory);
});



缓存查询方法
在上面的代码中,我们可以看到我们调用了一个ComileQuery方法,构建了一个委托,实际上,我们在业务编码中,也可以使用缓存查询,来提升业务系统的性能,虽然我们不能使用IDataBase的这个发给发,但是EF提供了一个静态类,里面的ComileQuery方法支持构建查询的委托,
看下面代码,我们可以调用这个方法缓存一个查询的方法,后面就不会再去调用很多的类,很多的方法来实现我们的查询,可以缓存起来,来提升我们的查询性能,同时这个ComileQuery方法最终也会调用到我们上面自定义的TestQueryCompiler的ComileQuery方法去,并且同步对同步,异步对异步.
- public class WeatherForecastController : ControllerBase
- {
- private static readonly string[] Summaries = new[]
- {
- "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
- };
- private Func<DecodeMicroMsgContext, IQueryable<Contact>> Func;
- private readonly ILogger<WeatherForecastController> _logger;
- private readonly IWebGetName webGetName;
- public WeatherForecastController(ILogger<WeatherForecastController> logger,IWebGetName webGetName, DecodeMicroMsgContext dbContext)
- {
- _logger = logger;
- this.webGetName = webGetName;
- DbContext = dbContext;
- }
- public DecodeMicroMsgContext DbContext { get; }
- [HttpGet(Name = "GetWeatherForecast")]
- public List<Contact> Get()
- {
- Func = EF.CompileQuery<DecodeMicroMsgContext, IQueryable<Contact>>(s => s.Contacts.Take(10));
- return DbContext.Contacts.Take(10).ToList();
- }
EF的IOC托管到WEB的IOC
在上面讲源码的时候,我们提到了一个方法,叫UseInternalServiceProvider,我们需要借助这个方法来把EF的ioc托管到web,同样是DBContextOptionsBuilder的方法,将web的ServiceProvider获取到并且调用这个方法,同时,我们还需要在Program.cs调用一个方法 builder.Services.AddEntityFrameworkSqlite();如果是其他数据库也是一样的道理,需要调用这样的方法,可以看第三方提供的库源码,或者文档,这里我是SQLITE数据库,就调用这个方法,这个方法是将SqlLite的一些服务注入到容器里,并且将我们的web容器传入到EF里面去,这样EF注入的服务是和Web注入的服务是在一起的,然后在调用UseInternalServiceProvider指定ServiceProvider就可以实现EF和WEB共用一个IOC。
下面是Program的Main方法的所有代码。
- public static void Main(string[] args)
- {
- var builder = WebApplication.CreateBuilder(args);
- builder.Services.AddScoped<IWebGetName,WebGetName>();
- builder.Services.AddScoped<IAsyncQueryProvider, TestQueryProvider>();
- builder.Services.AddScoped<IQueryCompiler, TestQueryCompiler>(s =>
- {
- var database = s.GetService<IDatabase>();
- var factory = s.GetService<IQueryContextFactory>();
- return new TestQueryCompiler(database, factory);
- });
- builder.Services.AddScoped<IDBGetName, DBGetName>();
- builder.Services.AddEntityFrameworkSqlite();
- builder.Services.AddDbContext<DecodeMicroMsgContext>((a, m) => {
- m.UseSqlite("Data Source=C:\\Users\\Chenxd\\Desktop\\资料\\CrackMsg\\CrackDb\\CrackDb\\bin\\Debug\\net7.0-windows\\TOOLS\\output\\decode_MicroMsg.db;");
- });
- builder.Services.AddControllers();
- // Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
- builder.Services.AddEndpointsApiExplorer();
- builder.Services.AddSwaggerGen();
- builder.Services.AddSingleton(() => builder.Services);
- var app = builder.Build();
- // Configure the HTTP request pipeline.
- if (app.Environment.IsDevelopment())
- {
- app.UseSwagger();
- app.UseSwaggerUI();
- }
- app.UseAuthorization();
- app.MapControllers();
- app.Run();
- }
- public static IServiceCollection AddEntityFrameworkSqlite(this IServiceCollection serviceCollection)
- {
- var builder = new EntityFrameworkRelationalServicesBuilder(serviceCollection)
- .TryAdd<LoggingDefinitions, SqliteLoggingDefinitions>()
- .TryAdd<IDatabaseProvider, DatabaseProvider<SqliteOptionsExtension>>()
- .TryAdd<IRelationalTypeMappingSource, SqliteTypeMappingSource>()
- .TryAdd<ISqlGenerationHelper, SqliteSqlGenerationHelper>()
- .TryAdd<IRelationalAnnotationProvider, SqliteAnnotationProvider>()
- .TryAdd<IModelValidator, SqliteModelValidator>()
- .TryAdd<IProviderConventionSetBuilder, SqliteConventionSetBuilder>()
- .TryAdd<IModificationCommandBatchFactory, SqliteModificationCommandBatchFactory>()
- .TryAdd<IRelationalConnection>(p => p.GetRequiredService<ISqliteRelationalConnection>())
- .TryAdd<IMigrationsSqlGenerator, SqliteMigrationsSqlGenerator>()
- .TryAdd<IRelationalDatabaseCreator, SqliteDatabaseCreator>()
- .TryAdd<IHistoryRepository, SqliteHistoryRepository>()
- .TryAdd<IRelationalQueryStringFactory, SqliteQueryStringFactory>()
- .TryAdd<IMethodCallTranslatorProvider, SqliteMethodCallTranslatorProvider>()
- .TryAdd<IAggregateMethodCallTranslatorProvider, SqliteAggregateMethodCallTranslatorProvider>()
- .TryAdd<IMemberTranslatorProvider, SqliteMemberTranslatorProvider>()
- .TryAdd<IQuerySqlGeneratorFactory, SqliteQuerySqlGeneratorFactory>()
- .TryAdd<IQueryableMethodTranslatingExpressionVisitorFactory, SqliteQueryableMethodTranslatingExpressionVisitorFactory>()
- .TryAdd<IRelationalSqlTranslatingExpressionVisitorFactory, SqliteSqlTranslatingExpressionVisitorFactory>()
- .TryAdd<IQueryTranslationPostprocessorFactory, SqliteQueryTranslationPostprocessorFactory>()
- .TryAdd<IUpdateSqlGenerator>(
- sp =>
- {
- // Support for the RETURNING clause on INSERT/UPDATE/DELETE was added in Sqlite 3.35.
- // Detect which version we're using, and fall back to the older INSERT/UPDATE+SELECT behavior on legacy versions.
- var dependencies = sp.GetRequiredService<UpdateSqlGeneratorDependencies>();
- return new Version(new SqliteConnection().ServerVersion) < new Version(3, 35)
- ? new SqliteLegacyUpdateSqlGenerator(dependencies)
- : new SqliteUpdateSqlGenerator(dependencies);
- })
- .TryAdd<ISqlExpressionFactory, SqliteSqlExpressionFactory>()
- .TryAddProviderSpecificServices(
- b => b.TryAddScoped<ISqliteRelationalConnection, SqliteRelationalConnection>());
- builder.TryAddCoreServices();
- return serviceCollection;
- }
- using EfDemo.Models;
- using Microsoft.EntityFrameworkCore.Infrastructure;
- using Microsoft.EntityFrameworkCore.Query.Internal;
- using Microsoft.EntityFrameworkCore.Query;
- using Microsoft.EntityFrameworkCore;
- using EfDemo.QueryableExtension;
- using EfDemo.DBExtension;
- using Microsoft.EntityFrameworkCore.Diagnostics;
- namespace EfDemo.DB
- {
- public partial class DecodeMicroMsgContext : DbContext
- {
- public DecodeMicroMsgContext(Func<IServiceCollection> func, IServiceProvider serviceProvider)
- {
- Func = func;
- ServiceProvider = serviceProvider;
- }
- public DecodeMicroMsgContext(DbContextOptions<DecodeMicroMsgContext> options, Func<IServiceCollection> func,IServiceProvider serviceProvider)
- : base(options)
- {
- Func = func;
- ServiceProvider = serviceProvider;
- }
- public virtual DbSet<AppInfo> AppInfos { get; set; }
- public virtual DbSet<BizInfo> BizInfos { get; set; }
- public virtual DbSet<BizName2Id> BizName2Ids { get; set; }
- public virtual DbSet<BizProfileInfo> BizProfileInfos { get; set; }
- public virtual DbSet<BizProfileV2> BizProfileV2s { get; set; }
- public virtual DbSet<BizSessionNewFeed> BizSessionNewFeeds { get; set; }
- public virtual DbSet<ChatInfo> ChatInfos { get; set; }
- public virtual DbSet<ChatLiveInfo> ChatLiveInfos { get; set; }
- public virtual DbSet<ChatRoom> ChatRooms { get; set; }
- public virtual DbSet<ChatRoomInfo> ChatRoomInfos { get; set; }
- public virtual DbSet<ChatroomTool> ChatroomTools { get; set; }
- public virtual DbSet<Contact> Contacts { get; set; }
- public virtual DbSet<ContactHeadImgUrl> ContactHeadImgUrls { get; set; }
- public virtual DbSet<ContactLabel> ContactLabels { get; set; }
- public virtual DbSet<DelayDownLoad> DelayDownLoads { get; set; }
- public virtual DbSet<FtschatroomTran> FtschatroomTrans { get; set; }
- public virtual DbSet<FtscontactTran> FtscontactTrans { get; set; }
- public virtual DbSet<MainConfig> MainConfigs { get; set; }
- public virtual DbSet<OpLog> OpLogs { get; set; }
- public virtual DbSet<PatInfo> PatInfos { get; set; }
- public virtual DbSet<RevokeMsgStorage> RevokeMsgStorages { get; set; }
- public virtual DbSet<Session> Sessions { get; set; }
- public virtual DbSet<TicketInfo> TicketInfos { get; set; }
- public virtual DbSet<TopStoryReddotInfo> TopStoryReddotInfos { get; set; }
- public IServiceProvider ServiceProvider { get; }
- public IServiceCollection ServiceDescriptors { get; }
- public Func<IServiceCollection> Func { get; }
- protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
- {
- optionsBuilder.UseInternalServiceProvider(ServiceProvider);
- // optionsBuilder.ReplaceService<IAsyncQueryProvider, TestQueryProvider>();
- // optionsBuilder.ReplaceService<IQueryCompiler, TestQueryCompiler>();
- // ((IDbContextOptionsBuilderInfrastructure)s).AddOrUpdateExtension(new Extension());
- //var interceptor = new List<IInterceptor>();
- //optionsBuilder.AddInterceptors();
- ((IDbContextOptionsBuilderInfrastructure)optionsBuilder).AddOrUpdateExtension(new ServiceExtension(Func));
- base.OnConfiguring(optionsBuilder);
- }
- protected override void OnModelCreating(ModelBuilder modelBuilder)
- {
- modelBuilder.Entity<AppInfo>(entity =>
- {
- entity.HasKey(e => e.InfoKey);
- entity.ToTable("AppInfo");
- entity.Property(e => e.Description4EnUs).HasColumnName("Description4EnUS");
- entity.Property(e => e.Description4ZhTw).HasColumnName("Description4ZhTW");
- entity.Property(e => e.Name4EnUs).HasColumnName("Name4EnUS");
- entity.Property(e => e.Name4ZhTw).HasColumnName("Name4ZhTW");
- entity.Property(e => e.Version).HasColumnType("INT");
- });
- modelBuilder.Entity<BizInfo>(entity =>
- {
- entity.HasKey(e => e.UserName);
- entity.ToTable("BizInfo");
- entity.Property(e => e.AcceptType).HasDefaultValueSql("0");
- entity.Property(e => e.BrandFlag).HasDefaultValueSql("0");
- entity.Property(e => e.BrandIconUrl).HasColumnName("BrandIconURL");
- entity.Property(e => e.Reserved1).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved3).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved5).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved7).HasDefaultValueSql("0");
- entity.Property(e => e.Type).HasDefaultValueSql("0");
- entity.Property(e => e.UpdateTime).HasDefaultValueSql("0");
- });
- modelBuilder.Entity<BizName2Id>(entity =>
- {
- entity.HasKey(e => e.UsrName);
- entity.ToTable("BizName2ID");
- });
- modelBuilder.Entity<BizProfileInfo>(entity =>
- {
- entity.HasKey(e => e.TableIndex);
- entity.ToTable("BizProfileInfo");
- entity.HasIndex(e => e.TableIndex, "versionIdx");
- entity.Property(e => e.TableIndex)
- .ValueGeneratedNever()
- .HasColumnName("tableIndex");
- entity.Property(e => e.TableDesc).HasColumnName("tableDesc");
- entity.Property(e => e.TableVersion)
- .HasColumnType("INTERGER")
- .HasColumnName("tableVersion");
- });
- modelBuilder.Entity<BizProfileV2>(entity =>
- {
- entity.HasKey(e => e.TalkerId);
- entity.ToTable("BizProfileV2");
- entity.HasIndex(e => e.TimeStamp, "BizProfileV2TimeIdx");
- entity.Property(e => e.TalkerId).ValueGeneratedNever();
- });
- modelBuilder.Entity<BizSessionNewFeed>(entity =>
- {
- entity.HasKey(e => e.TalkerId);
- entity.HasIndex(e => e.CreateTime, "BizSessionNewFeedsCreateTimeIdx");
- entity.HasIndex(e => e.UpdateTime, "BizSessionNewFeedsUpdateTimeIdx");
- entity.Property(e => e.TalkerId).ValueGeneratedNever();
- });
- modelBuilder.Entity<ChatInfo>(entity =>
- {
- entity
- .HasNoKey()
- .ToTable("ChatInfo");
- entity.HasIndex(e => e.Username, "ChatInfoUserNameIndex");
- });
- modelBuilder.Entity<ChatLiveInfo>(entity =>
- {
- entity
- .HasNoKey()
- .ToTable("ChatLiveInfo");
- entity.HasIndex(e => new { e.RoomName, e.LiveId }, "IX_ChatLiveInfo_RoomName_LiveId").IsUnique();
- entity.HasIndex(e => e.LiveId, "ChatLiveInfoLiveIdIdx");
- entity.HasIndex(e => e.RoomName, "ChatLiveInfoRoomNamex");
- });
- modelBuilder.Entity<ChatRoom>(entity =>
- {
- entity.HasKey(e => e.ChatRoomName);
- entity.ToTable("ChatRoom");
- entity.Property(e => e.ChatRoomFlag)
- .HasDefaultValueSql("0")
- .HasColumnType("INT");
- entity.Property(e => e.IsShowName).HasDefaultValueSql("0");
- entity.Property(e => e.Owner).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved1).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved3).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved5).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved7).HasDefaultValueSql("0");
- });
- modelBuilder.Entity<ChatRoomInfo>(entity =>
- {
- entity.HasKey(e => e.ChatRoomName);
- entity.ToTable("ChatRoomInfo");
- entity.Property(e => e.AnnouncementPublishTime).HasDefaultValueSql("0");
- entity.Property(e => e.ChatRoomStatus).HasDefaultValueSql("0");
- entity.Property(e => e.InfoVersion).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved1).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved3).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved5).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved7).HasDefaultValueSql("0");
- });
- modelBuilder.Entity<ChatroomTool>(entity =>
- {
- entity
- .HasNoKey()
- .ToTable("ChatroomTool");
- entity.HasIndex(e => e.ChatroomUsername, "IX_ChatroomTool_ChatroomUsername").IsUnique();
- });
- modelBuilder.Entity<Contact>(entity =>
- {
- entity.HasKey(e => e.UserName);
- entity.ToTable("Contact");
- entity.HasIndex(e => e.Reserved2, "Contact_Idx0");
- entity.Property(e => e.ChatRoomNotify).HasDefaultValueSql("0");
- entity.Property(e => e.ChatRoomType).HasColumnType("INT");
- entity.Property(e => e.DelFlag).HasDefaultValueSql("0");
- entity.Property(e => e.LabelIdlist).HasColumnName("LabelIDList");
- entity.Property(e => e.Pyinitial).HasColumnName("PYInitial");
- entity.Property(e => e.RemarkPyinitial).HasColumnName("RemarkPYInitial");
- entity.Property(e => e.Reserved1).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved2).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved5).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved8).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved9).HasDefaultValueSql("0");
- entity.Property(e => e.Type).HasDefaultValueSql("0");
- entity.Property(e => e.VerifyFlag).HasDefaultValueSql("0");
- });
- modelBuilder.Entity<ContactHeadImgUrl>(entity =>
- {
- entity.HasKey(e => e.UsrName);
- entity.ToTable("ContactHeadImgUrl");
- entity.HasIndex(e => e.Reverse0, "reverse0Index");
- entity.Property(e => e.UsrName).HasColumnName("usrName");
- entity.Property(e => e.BigHeadImgUrl).HasColumnName("bigHeadImgUrl");
- entity.Property(e => e.HeadImgMd5).HasColumnName("headImgMd5");
- entity.Property(e => e.Reverse0)
- .HasColumnType("INT")
- .HasColumnName("reverse0");
- entity.Property(e => e.Reverse1).HasColumnName("reverse1");
- entity.Property(e => e.SmallHeadImgUrl).HasColumnName("smallHeadImgUrl");
- });
- modelBuilder.Entity<ContactLabel>(entity =>
- {
- entity.HasKey(e => e.LabelId);
- entity.ToTable("ContactLabel");
- entity.Property(e => e.LabelId).ValueGeneratedNever();
- });
- modelBuilder.Entity<DelayDownLoad>(entity =>
- {
- entity
- .HasNoKey()
- .ToTable("DelayDownLoad");
- entity.HasIndex(e => e.MessageServId, "IX_DelayDownLoad_MessageServId").IsUnique();
- });
- modelBuilder.Entity<FtschatroomTran>(entity =>
- {
- entity
- .HasNoKey()
- .ToTable("FTSChatroomTrans");
- entity.Property(e => e.DisplayName).HasColumnName("displayName");
- entity.Property(e => e.GroupUsername).HasColumnName("groupUsername");
- entity.Property(e => e.Nickname).HasColumnName("nickname");
- entity.Property(e => e.Operation).HasColumnName("operation");
- entity.Property(e => e.Reserve1).HasColumnName("reserve1");
- entity.Property(e => e.Reserve2).HasColumnName("reserve2");
- entity.Property(e => e.Username).HasColumnName("username");
- });
- modelBuilder.Entity<FtscontactTran>(entity =>
- {
- entity
- .HasNoKey()
- .ToTable("FTSContactTrans");
- entity.Property(e => e.Reserve1).HasColumnName("reserve1");
- entity.Property(e => e.Reserve2).HasColumnName("reserve2");
- entity.Property(e => e.Username).HasColumnName("username");
- });
- modelBuilder.Entity<MainConfig>(entity =>
- {
- entity.HasKey(e => e.Key);
- entity.ToTable("MainConfig");
- entity.HasIndex(e => e.Reserved0, "MainConfigReserved0Idx");
- entity.HasIndex(e => e.Reserved1, "MainConfigReserved1Idx");
- entity.Property(e => e.Reserved0).HasColumnType("INT");
- entity.Property(e => e.Reserved1).HasColumnType("INT");
- });
- modelBuilder.Entity<OpLog>(entity =>
- {
- entity.ToTable("OpLog");
- entity.Property(e => e.Id)
- .ValueGeneratedNever()
- .HasColumnName("ID");
- entity.Property(e => e.CmditemBuffer).HasColumnName("CMDItemBuffer");
- });
- modelBuilder.Entity<PatInfo>(entity =>
- {
- entity.HasKey(e => e.Username);
- entity.ToTable("PatInfo");
- entity.Property(e => e.Username).HasColumnName("username");
- entity.Property(e => e.Reserved1)
- .HasDefaultValueSql("0")
- .HasColumnName("reserved1");
- entity.Property(e => e.Reserved2)
- .HasDefaultValueSql("0")
- .HasColumnName("reserved2");
- entity.Property(e => e.Reserved3)
- .HasDefaultValueSql("0")
- .HasColumnName("reserved3");
- entity.Property(e => e.Reserved4)
- .HasDefaultValueSql("0")
- .HasColumnName("reserved4");
- entity.Property(e => e.Reserved5).HasColumnName("reserved5");
- entity.Property(e => e.Reserved6).HasColumnName("reserved6");
- entity.Property(e => e.Reserved7).HasColumnName("reserved7");
- entity.Property(e => e.Reserved8).HasColumnName("reserved8");
- entity.Property(e => e.Reserved9).HasColumnName("reserved9");
- entity.Property(e => e.Suffix).HasColumnName("suffix");
- });
- modelBuilder.Entity<RevokeMsgStorage>(entity =>
- {
- entity.HasKey(e => e.CreateTime);
- entity.ToTable("RevokeMsgStorage");
- entity.HasIndex(e => e.MsgSvrId, "MsgSvrId_Idx");
- entity.HasIndex(e => e.RevokeSvrId, "RevokeSvrID_Idx");
- entity.Property(e => e.CreateTime).ValueGeneratedNever();
- entity.Property(e => e.MsgSvrId)
- .HasColumnType("INTERGER")
- .HasColumnName("MsgSvrID");
- entity.Property(e => e.RevokeSvrId)
- .HasColumnType("INTERGER")
- .HasColumnName("RevokeSvrID");
- });
- modelBuilder.Entity<Session>(entity =>
- {
- entity.HasKey(e => e.StrUsrName);
- entity.ToTable("Session");
- entity.HasIndex(e => e.NOrder, "nOrderIndex");
- entity.Property(e => e.StrUsrName).HasColumnName("strUsrName");
- entity.Property(e => e.BytesXml).HasColumnName("bytesXml");
- entity.Property(e => e.EditContent).HasColumnName("editContent");
- entity.Property(e => e.NIsSend).HasColumnName("nIsSend");
- entity.Property(e => e.NMsgLocalId).HasColumnName("nMsgLocalID");
- entity.Property(e => e.NMsgStatus).HasColumnName("nMsgStatus");
- entity.Property(e => e.NMsgType).HasColumnName("nMsgType");
- entity.Property(e => e.NOrder)
- .HasDefaultValueSql("0")
- .HasColumnType("INT")
- .HasColumnName("nOrder");
- entity.Property(e => e.NStatus).HasColumnName("nStatus");
- entity.Property(e => e.NTime).HasColumnName("nTime");
- entity.Property(e => e.NUnReadCount)
- .HasDefaultValueSql("0")
- .HasColumnName("nUnReadCount");
- entity.Property(e => e.OthersAtMe)
- .HasColumnType("INT")
- .HasColumnName("othersAtMe");
- entity.Property(e => e.ParentRef).HasColumnName("parentRef");
- entity.Property(e => e.Reserved0).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved2).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved4).HasDefaultValueSql("0");
- entity.Property(e => e.StrContent).HasColumnName("strContent");
- entity.Property(e => e.StrNickName).HasColumnName("strNickName");
- });
- modelBuilder.Entity<TicketInfo>(entity =>
- {
- entity.HasKey(e => e.UserName);
- entity.ToTable("TicketInfo");
- entity.Property(e => e.Reserved1).HasDefaultValueSql("0");
- entity.Property(e => e.Reserved3).HasDefaultValueSql("0");
- });
- modelBuilder.Entity<TopStoryReddotInfo>(entity =>
- {
- entity.HasKey(e => e.MsgId);
- entity.ToTable("TopStoryReddotInfo");
- entity.Property(e => e.H5version).HasColumnName("H5Version");
- });
- OnModelCreatingPartial(modelBuilder);
- }
- partial void OnModelCreatingPartial(ModelBuilder modelBuilder);
- }
- }
结尾
在本文中,我们一共讲了AddDbContext做了什么,DBContext的构造函数又做了那些事情,在写了不托管EF的ioc到WEB的ioc的场景下如果注入服务到EF的ioc中,以及如何拦截增删改查的方式,提升查询性能的方式,以及最后的EF的ioc托管到WEB的ioc,本文作为源码讲解的第一章,觉得写的有点多,如果又看不懂的地方,或者代码下载下来没办法运行或者保存的地方可以随时联系我,QQ934550201.我们下次再见。数据库是我破解的我本地的微信数据的一部分,emmm作为了本次的例子,我希望大家能够合理看待我的这个数据库的数据,不要做一些不好的事情,谢谢大家。
本次的代码例子地址
链接:https://pan.baidu.com/s/1w6kFG5MCJYE0jzEBxjQTKw
提取码:foin
之前AOP的代码例子
链接:https://pan.baidu.com/s/1AJe4-KhjIESbDtFNqM968Q
提取码:jp20