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。
代码语言：javascript复制 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，
代码语言：javascript复制 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。
代码语言：javascript复制 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。
代码语言：javascript复制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
代码语言：javascript复制 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。
代码语言：javascript复制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。
代码语言：javascript复制 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。
代码语言：javascript复制 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。
代码语言：javascript复制 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://cloud.tencent.com/developer/article/2153815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。
代码语言：javascript复制 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://cloud.tencent.com/developer/article/2153783，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
代码语言：javascript复制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
代码语言：javascript复制 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
代码语言：javascript复制 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，
代码语言：javascript复制 #未接管
optionsBuilder.ReplaceService<IAsyncQueryProvider,TestQueryProvider >();
optionsBuilder.ReplaceService<IQueryCompiler,TestQueryCompiler>();
#接管IOC
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.
代码语言：javascript复制 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。
代码语言：javascript复制 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。
