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。

好吧，目前我正在使用Express分析器，缺点是它只适用于MS SQL Server。你可以在这里找到这个工具:https://expressprofiler.codeplex.com/

使用实体框架核心3.x进行日志记录

实体框架核心通过日志系统发出SQL。只有一些小技巧。您必须指定一个ILoggerFactory和一个筛选器。下面是本文中的一个例子

创建工厂:

var loggerFactory = LoggerFactory.Create(builder =>
{
    builder
    .AddConsole((options) => { })
    .AddFilter((category, level) =>
        category == DbLoggerCategory.Database.Command.Name
        && level == LogLevel.Information);
});

告诉DbContext在onconfigure方法中使用工厂:

optionsBuilder.UseLoggerFactory(_loggerFactory);

从这里，您可以获得更复杂的信息，并与Log方法挂钩以提取有关执行SQL的详细信息。有关完整讨论，请参阅文章。

public class EntityFrameworkSqlLogger : ILogger
{
    #region Fields
    Action<EntityFrameworkSqlLogMessage> _logMessage;
    #endregion
    #region Constructor
    public EntityFrameworkSqlLogger(Action<EntityFrameworkSqlLogMessage> logMessage)
    {
        _logMessage = logMessage;
    }
    #endregion
    #region Implementation
    public IDisposable BeginScope<TState>(TState state)
    {
        return default;
    }
    public bool IsEnabled(LogLevel logLevel)
    {
        return true;
    }
    public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
    {
        if (eventId.Id != 20101)
        {
            //Filter messages that aren't relevant.
            //There may be other types of messages that are relevant for other database platforms...
            return;
        }
        if (state is IReadOnlyList<KeyValuePair<string, object>> keyValuePairList)
        {
            var entityFrameworkSqlLogMessage = new EntityFrameworkSqlLogMessage
            (
                eventId,
                (string)keyValuePairList.FirstOrDefault(k => k.Key == "commandText").Value,
                (string)keyValuePairList.FirstOrDefault(k => k.Key == "parameters").Value,
                (CommandType)keyValuePairList.FirstOrDefault(k => k.Key == "commandType").Value,
                (int)keyValuePairList.FirstOrDefault(k => k.Key == "commandTimeout").Value,
                (string)keyValuePairList.FirstOrDefault(k => k.Key == "elapsed").Value
            );
            _logMessage(entityFrameworkSqlLogMessage);
        }
    }
    #endregion
}

您可以执行以下操作:

IQueryable query = from x in appEntities
             where x.id == 32
             select x;

var sql = ((System.Data.Objects.ObjectQuery)query).ToTraceString();

或EF6:

var sql = ((System.Data.Entity.Core.Objects.ObjectQuery)query)
            .ToTraceString();

或EF6.3+:

var sql = ((dynamic)flooringStoresProducts).Sql;

这将为您提供生成的SQL。

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.

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