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.

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

如果您正在使用DbContext，您可以执行以下操作来获取SQL:

var result = from i in myContext.appEntities
             select new Model
             {
                 field = i.stuff,
             };
var sql = result.ToString();

在我的EF 6+的情况下，而不是在立即窗口中使用这个来查找查询字符串:

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

我最终不得不使用这个来获得生成的SQL命令:

var sql = ((System.Data.Entity.Infrastructure.DbQuery<<>f__AnonymousType3<string,string,string,short,string>>)query).ToString();

当然，您的匿名类型签名可能有所不同。

HTH.

IQueryable query = from x in appEntities
                   where x.id = 32
                   select x;
var queryString = query.ToString();

将返回sql查询。使用EntityFramework的数据上下文进行工作

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
}