对我来说，使用EF6和Visual Studio 2015，我在即时窗口中输入查询，它给了我生成的SQL语句

对于那些使用Entity Framework 6及以上版本的用户，如果你想在Visual Studio中查看输出SQL(就像我做的那样)，你必须使用新的日志/拦截功能。

添加下面这行代码将在Visual Studio输出面板中输出生成的SQL(以及其他与执行相关的详细信息):

using (MyDatabaseEntities context = new MyDatabaseEntities())
{
    context.Database.Log = s => System.Diagnostics.Debug.WriteLine(s);
    // query the database using EF here.
}

有关登录EF6的更多信息，请参阅这个漂亮的博客系列:http://blog.oneunicorn.com/2013/05/08/ef6-sql-logging-part-1-simple-logging/

注意:确保在DEBUG模式下运行项目。

虽然这里有很好的答案，但没有一个完全解决了我的问题(我希望从任何IQueryable DbContext中获得整个SQL语句，包括参数)。下面的代码就是这样做的。它是来自谷歌的代码片段的组合。我只用EF6+测试过。

说句题外话，这项任务花的时间比我想象的要长得多。恕我直言，实体框架中的抽象有点太多了。

首先是使用。您需要显式引用'System.Data.Entity.dll'。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;
using System.Data.Common;
using System.Data.Entity.Core.Objects;
using System.Data.Entity;
using System.Data;
using System.Data.Entity.Infrastructure;
using System.Reflection;

下面的类将一个IQueryable转换为一个DataTable。根据您的需要修改:

public class EntityFrameworkCommand
{
    DbContext Context;

    string SQL;

    ObjectParameter[] Parameters;

    public EntityFrameworkCommand Initialize<T>(DbContext context, IQueryable<T> query)
    {
        Context = context;
        var dbQuery = query as DbQuery<T>;
        // get the IInternalQuery internal variable from the DbQuery object
        var iqProp = dbQuery.GetType().GetProperty("InternalQuery", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public);
        var iq = iqProp.GetValue(dbQuery, null);
        // get the ObjectQuery internal variable from the IInternalQuery object
        var oqProp = iq.GetType().GetProperty("ObjectQuery", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public);
        var objectQuery = oqProp.GetValue(iq, null) as ObjectQuery<T>;
        SQL = objectQuery.ToTraceString();
        Parameters = objectQuery.Parameters.ToArray();
        return this;
    }

    public DataTable GetData()
    {
        DataTable dt = new DataTable();
        var connection = Context.Database.Connection;
        var state = connection.State;
        if (!(state == ConnectionState.Open))
            connection.Open();
        using (var cmd = connection.CreateCommand())
        {
            cmd.CommandText = SQL;
            foreach (var p in Parameters)
            {
                var param = cmd.CreateParameter();
                param.Name = "@" + p.Name;
                param.Value = p.Value;
                cmd.Parameters.Add(param);
            }
            using (var da = DbProviderFactories.GetFactory(connection).CreateDataAdapter())
            {
                da.SelectCommand = cmd;
                da.Fill(dt);
            }
        }
        if (!(state == ConnectionState.Open))
            connection.Close();
        return dt;
    }
}

要使用，只需如下所示调用它:

var context = new MyContext();
var data = ....//Query, return type can be anonymous
    .AsQueryable();
var dt = new EntityFrameworkCommand()
    .Initialize(context, data)
    .GetData();

SQL Management Studio => Tools => SQL Server分析器

File =>新建跟踪…

使用Template =>空白

事件选择=> T-SQL

左侧检查:SP.StmtComplete

列筛选器可用于选择特定的ApplicationName或DatabaseName

启动该概要文件运行，然后触发查询。

点击这里获取来源信息

我的答案是针对EF core的。我参考了这个github问题，以及配置DbContext的文档:

简单的

重写DbContext类(YourCustomDbContext)的onconfiguration方法，如下所示使用ConsoleLoggerProvider;你的查询应该记录到控制台:

public class YourCustomDbContext : DbContext
{
    #region DefineLoggerFactory
    public static readonly LoggerFactory MyLoggerFactory
        = new LoggerFactory(new[] {new ConsoleLoggerProvider((_, __) => true, true)});
    #endregion


    #region RegisterLoggerFactory
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder
            .UseLoggerFactory(MyLoggerFactory); // Warning: Do not create a new ILoggerFactory instance each time                
    #endregion
}

复杂的

这个Complex case避免覆盖DbContext onconfiguration方法。，这在文档中是不鼓励的:“这种方法不适合测试，除非测试的目标是整个数据库。”

这个复杂的案例使用:

启动类ConfigureServices方法中的IServiceCollection (而不是重写onconfiguration方法;好处是DbContext和你想要使用的ILoggerProvider之间的耦合更松散) ILoggerProvider的实现(而不是使用上面所示的ConsoleLoggerProvider实现;好处是我们的实现展示了我们如何将日志记录到文件(我没有看到一个文件日志记录提供程序与EF核心))

是这样的:

public class Startup

    public void ConfigureServices(IServiceCollection services)
    {
        ...
        var lf = new LoggerFactory();
        lf.AddProvider(new MyLoggerProvider());

        services.AddDbContext<YOUR_DB_CONTEXT>(optionsBuilder => optionsBuilder
                .UseSqlServer(connection_string)
                //Using the LoggerFactory 
                .UseLoggerFactory(lf));
        ...
    }
}

这里是MyLoggerProvider的实现(以及它的MyLogger，它将其日志附加到您可以配置的文件中;您的EF Core查询将出现在文件中。)

public class MyLoggerProvider : ILoggerProvider
{
    public ILogger CreateLogger(string categoryName)
    {
        return new MyLogger();
    }

    public void Dispose()
    { }

    private class MyLogger : ILogger
    {
        public bool IsEnabled(LogLevel logLevel)
        {
            return true;
        }

        public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
        {
            File.AppendAllText(@"C:\temp\log.txt", formatter(state, exception));
            Console.WriteLine(formatter(state, exception));
        }

        public IDisposable BeginScope<TState>(TState state)
        {
            return null;
        }
    } 
}

有两种方法:

To view the SQL that will be generated, simply call ToTraceString(). You can add it into your watch window and set a breakpoint to see what the query would be at any given point for any LINQ query. You can attach a tracer to your SQL server of choice, which will show you the final query in all its gory detail. In the case of MySQL, the easiest way to trace the queries is simply to tail the query log with tail -f. You can learn more about MySQL's logging facilities in the official documentation. For SQL Server, the easiest way is to use the included SQL Server profiler.