entity framework6 – 定时查询

我正在使用Entity Framework 6，它是非常棒的数据库拦截器function，用于记录从应用程序数据库发送的查询。 但是，我正在努力为这些查询计时，我有一个长时间运行的查询，返回数十万到数百万行，因此需要大约6到15秒，具体取决于此查询将返回的数据量。 entity framework返回一个SqlDataReader，因为我无法获得获取结果所需的确切时间。 我想知道从查询发送到读取最后一行的时间的完整执行时间。 有没有办法可以做到。

Answer 1

这是我通常用于EF的记录器。

public class EFLoggerForTesting : IDbCommandInterceptor { static readonly ConcurrentDictionary m_StartTime = new ConcurrentDictionary(); public void ReaderExecuted(DbCommand command, DbCommandInterceptionContext interceptionContext) { Log(command, interceptionContext); } public void NonQueryExecuted(DbCommand command, DbCommandInterceptionContext interceptionContext) { Log(command, interceptionContext); } public void ScalarExecuted(DbCommand command, DbCommandInterceptionContext 

不幸的是，文档不存在，所以我不知道这是否适用于您的场景。

Answer 2

如果您使用的是Web应用程序，可以试试Glimpse： http ： //getglimpse.com/ 。 否则，请尝试MiniProfiler： http ： //miniprofiler.com/ 。

Answer 3

正如@Ricardo Peres的回答所暗示的那样，Glimpse对此很有好处。 它附带了Glimpse.Ado插件，可用于轻松分析任何DbConnection ，这是在此扩展的主要类。

Glimpse中ADO的手动集成点是将DbConnection包装在GlimpseDbConnection ，如本博客文章中所示： http ： GlimpseDbConnection 。 像EF这样的其他提供商会自动与Glimpse.Ef软件包集成。

如果你仍然决定要手动实现这一点，我建议你自己包装DbConneciton并使用它来代替常规DbConnection 。 你可以做这个简单的计时。

你可以看看Glimpse如何在他们的github上做到这一点： https ： //github.com/Glimpse/Glimpse/tree/master/source/Glimpse.Ado/AlternateType

或者，始终可以选择在存储库级别或方法级别添加此类日志记录，具体取决于您需要多少日志记录。

Answer 4

相当简单，但你不能使用System.Timers.Timer对象？ 在EF代码之前调用start，在EF代码之后调用end。 如果你有异步代码，你可以调用.Result并删除等待，以便同步运行代码并计时。 除此之外，如果您使用SQL分析器并从另一个中减去一个值（Timer – Profiler），您将了解EF代码执行的时间。

Answer 5

下面是我原始DatabaseLogFormatter简化版本。 主要的区别是这个没有过滤，我没有记录实际的SQL查询或它的参数（因为我只对查询计时感兴趣）。 它在打开连接，执行查询以及何时再次关闭连接时进行记录。 正如@ aske-b 上面注意到使用DateTime （正如接受的答案所做的那样）并不是很准确。

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 public class CustomDatabaseLogFormatter : IDbCommandInterceptor, IDbConnectionInterceptor { private readonly Action _writeAction; private readonly Stopwatch _stopwatch = new Stopwatch(); /// 
 /// Creates a formatter that will log every command from any context and also commands that do not originate from a context. /// 
 ///  /// This constructor is not used when a delegate is set on . Instead it can be /// used by setting the formatter directly using . ///  /// The delegate to which output will be sent. public CustomDatabaseLogFormatter(Action writeAction) { Check.NotNull(writeAction, "writeAction"); _writeAction = writeAction; } internal Action WriteAction { get { return _writeAction; } } /// 
 /// Writes the given string to the underlying write delegate. /// 
 /// The string to write. protected virtual void Write(string output) { _writeAction(output); } /// 
 /// The stopwatch used to time executions. This stopwatch is started at the end of /// , , and  /// methods and is stopped at the beginning of the , , /// and  methods. If these methods are overridden and the stopwatch is being used /// then the overrides should either call the base method or start/stop the stopwatch themselves. /// 
 /// The stopwatch. protected internal Stopwatch Stopwatch { get { return _stopwatch; } } private void RestartStopwatch() { Stopwatch.Restart(); } private void StopStopwatch() { Stopwatch.Stop(); } #region IDbCommandInterceptor /// 
 /// This method is called before a call to  or /// one of its async counterparts is made. /// Starts the stopwatch returned from . /// 
 /// The command being executed. /// Contextual information associated with the call. public virtual void NonQueryExecuting(DbCommand command, DbCommandInterceptionContext interceptionContext) { Check.NotNull(command, "command"); Check.NotNull(interceptionContext, "interceptionContext"); RestartStopwatch(); } /// 
 /// This method is called after a call to  or /// one of its async counterparts is made. /// Stops the stopwatch returned from  and calls . /// 
 /// The command being executed. /// Contextual information associated with the call. public virtual void NonQueryExecuted(DbCommand command, DbCommandInterceptionContext interceptionContext) { Check.NotNull(command, "command"); Check.NotNull(interceptionContext, "interceptionContext"); StopStopwatch(); Executed(command, interceptionContext); } /// 
 /// This method is called before a call to  or /// one of its async counterparts is made. /// Starts the stopwatch returned from . /// 
 /// The command being executed. /// Contextual information associated with the call. public virtual void ReaderExecuting(DbCommand command, DbCommandInterceptionContext interceptionContext) { Check.NotNull(command, "command"); Check.NotNull(interceptionContext, "interceptionContext"); RestartStopwatch(); } /// 
 /// This method is called after a call to  or /// one of its async counterparts is made. /// Stops the stopwatch returned from  and calls . /// 
 /// The command being executed. /// Contextual information associated with the call. public virtual void ReaderExecuted(DbCommand command, DbCommandInterceptionContext interceptionContext) { Check.NotNull(command, "command"); Check.NotNull(interceptionContext, "interceptionContext"); StopStopwatch(); Executed(command, interceptionContext); } /// 
 /// This method is called before a call to  or /// one of its async counterparts is made. /// Starts the stopwatch returned from . /// 
 /// The command being executed. /// Contextual information associated with the call. public virtual void ScalarExecuting(DbCommand command, DbCommandInterceptionContext 

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 internal class Check { public static T NotNull(T value, string parameterName) where T : class { if (value == null) { throw new ArgumentNullException(parameterName); } return value; } } 

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 StringResources.resx: CommandLogCanceled Canceled in {0} ms{1} CommandLogComplete Completed in {0} ms with result: {1} CommandLogFailed Failed in {0} ms with error: {1} ConnectionClosedLog Closed connection at {0} ConnectionCloseErrorLog Failed to close connection at {0} with error: {1} ConnectionOpenCanceledLog Cancelled open connection at {0} ConnectionOpenedLog Opened connection at {0} ConnectionOpenedLogAsync Opened connection asynchronously at {0} ConnectionOpenErrorLog Failed to open connection at {0} with error: {1} ConnectionOpenErrorLogAsync Failed to open connection asynchronously at {0} with error: {1} 

Answer 6

您可以尝试这里解释的示例

在这个例子中，我们在命令开始执行时启动Stopwatch ，并在命令完成时停止Stopwatch ，这样我们就可以识别慢速查询并记录它们。

 public class SqlMonitorInterceptor : IDbCommandInterceptor { private static readonly ILog logger = LogManager.GetCurrentClassLogger(); private static readonly int sqlWarningThresholdMs = int.Parse(ConfigurationManager.AppSettings["sqlPerformance_warningThresholdMilliseconds"]); private readonly Stopwatch _stopwatch = new Stopwatch(); public void NonQueryExecuting(DbCommand command, DbCommandInterceptionContext interceptionContext) { CommandExecuting(); } public void NonQueryExecuted(DbCommand command, DbCommandInterceptionContext interceptionContext) { CommandExecuted(command, interceptionContext); } public void ReaderExecuting(DbCommand command, DbCommandInterceptionContext interceptionContext) { CommandExecuting(); } public void ReaderExecuted(DbCommand command, DbCommandInterceptionContext interceptionContext) { CommandExecuted(command, interceptionContext); } public void ScalarExecuting(DbCommand command, DbCommandInterceptionContext