从 Entity Framework Core IQueryable<T> 获取 SQL 代码
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【中文标题】从 Entity Framework Core IQueryable<T> 获取 SQL 代码【英文标题】:Get SQL code from an Entity Framework Core IQueryable<T> 【发布时间】:2016-09-28 09:48:21 【问题描述】:我正在使用 Entity Framework Core,我需要查看正在生成哪些 SQL 代码。在以前版本的实体框架中,我可以使用以下内容:
string sql = ((System.Data.Objects.ObjectQuery)query).ToTraceString();
其中 query 是一个 IQueryable 对象...但 ToTraceString 在 EF Core 中不可用。
如何在 EF Core 中做类似的事情?
【问题讨论】:
How to log queries using Entity Framework 7?的可能重复 你可以试试这个:rion.io/2016/10/19/…. 【参考方案1】:EF 核心 5/6 / 网络 5/6
query.ToQueryString()
见Documentation ToQueryString()和What's New in EF Core 5.0
var query = _context.Widgets.Where(w => w.IsReal && w.Id == 42);
var sql = query.ToQueryString();
对于较旧的网络核心框架,可以使用扩展。
核心 2.1.2
using System.Linq;
using System.Reflection;
using Microsoft.EntityFrameworkCore.Query;
using Microsoft.EntityFrameworkCore.Query.Internal;
using Microsoft.EntityFrameworkCore.Query.Expressions;
using Microsoft.EntityFrameworkCore.Query.Sql;
using static Microsoft.EntityFrameworkCore.DbLoggerCategory;
public static class QueryableExtensions
private static readonly TypeInfo QueryCompilerTypeInfo = typeof(QueryCompiler).GetTypeInfo();
private static readonly FieldInfo QueryCompilerField = typeof(EntityQueryProvider).GetTypeInfo().DeclaredFields.First(x => x.Name == "_queryCompiler");
private static readonly FieldInfo QueryModelGeneratorField = typeof(QueryCompiler).GetTypeInfo().DeclaredFields.First(x => x.Name == "_queryModelGenerator");
private static readonly FieldInfo DataBaseField = QueryCompilerTypeInfo.DeclaredFields.Single(x => x.Name == "_database");
private static readonly PropertyInfo DatabaseDependenciesField = typeof(Database).GetTypeInfo().DeclaredProperties.Single(x => x.Name == "Dependencies");
public static string ToSql<TEntity>(this IQueryable<TEntity> query)
var queryCompiler = (QueryCompiler) QueryCompilerField.GetValue(query.Provider);
var queryModelGenerator = (QueryModelGenerator)QueryModelGeneratorField.GetValue(queryCompiler);
var queryModel = queryModelGenerator.ParseQuery(query.Expression);
var database = DataBaseField.GetValue(queryCompiler);
var databaseDependencies = (DatabaseDependencies) DatabaseDependenciesField.GetValue(database);
var queryCompilationContext = databaseDependencies.QueryCompilationContextFactory.Create(false);
var modelVisitor = (RelationalQueryModelVisitor) queryCompilationContext.CreateQueryModelVisitor();
modelVisitor.CreateQueryExecutor<TEntity>(queryModel);
var sql = modelVisitor.Queries.First().ToString();
return sql;
EF Core 3.0
public static string ToSql<TEntity>(this IQueryable<TEntity> query)
using var enumerator = query.Provider.Execute<IEnumerable<TEntity>>(query.Expression).GetEnumerator();
var enumeratorType = enumerator.GetType();
var selectFieldInfo = enumeratorType.GetField("_selectExpression", BindingFlags.NonPublic | BindingFlags.Instance) ?? throw new InvalidOperationException($"cannot find field _selectExpression on type enumeratorType.Name");
var sqlGeneratorFieldInfo = enumeratorType.GetField("_querySqlGeneratorFactory", BindingFlags.NonPublic | BindingFlags.Instance) ?? throw new InvalidOperationException($"cannot find field _querySqlGeneratorFactory on type enumeratorType.Name");
var selectExpression = selectFieldInfo.GetValue(enumerator) as SelectExpression ?? throw new InvalidOperationException($"could not get SelectExpression");
var factory = sqlGeneratorFieldInfo.GetValue(enumerator) as IQuerySqlGeneratorFactory ?? throw new InvalidOperationException($"could not get IQuerySqlGeneratorFactory");
var sqlGenerator = factory.Create();
var command = sqlGenerator.GetCommand(selectExpression);
var sql = command.CommandText;
return sql;
见RosiOli的要点
EF Core 3.1
using System.Linq;
using System.Reflection;
using System.Collections.Generic;
using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
using Microsoft.EntityFrameworkCore.Query;
public static string ToSql<TEntity>(this IQueryable<TEntity> query) where TEntity : class
using var enumerator = query.Provider.Execute<IEnumerable<TEntity>>(query.Expression).GetEnumerator();
var relationalCommandCache = enumerator.Private("_relationalCommandCache");
var selectExpression = relationalCommandCache.Private<SelectExpression>("_selectExpression");
var factory = relationalCommandCache.Private<IQuerySqlGeneratorFactory>("_querySqlGeneratorFactory");
var sqlGenerator = factory.Create();
var command = sqlGenerator.GetCommand(selectExpression);
string sql = command.CommandText;
return sql;
private static object Private(this object obj, string privateField) => obj?.GetType().GetField(privateField, BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(obj);
private static T Private<T>(this object obj, string privateField) => (T)obj?.GetType().GetField(privateField, BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(obj);
EF net core team 也跟踪该问题,并计划在下一个版本中发布。
【讨论】:
您能否举例说明如何编写此代码以使用IQueryable
而不是IQueryable<T>
?
我想你总是有一个IQueryable<T>
。请参阅上面的 widget
示例。你有一个只有 IQueryable 的例子吗?
var relationalCommandCache = enumerator.Private("_relationalCommandCache");返回空
对于EF Core 2.1
,这些是我唯一需要的using
s(以防止引用不明确的问题)。 using System.Linq; using System.Reflection; using Microsoft.EntityFrameworkCore.Query; using Microsoft.EntityFrameworkCore.Query.Internal; using Microsoft.EntityFrameworkCore.Storage;
请注意,如果 Query 包含 Func<T>
,.ToQueryString() 方法确实会引发异常。【参考方案2】:
此答案适用于 EF Core 2.1。
对于 EF Core 3.0 和 3.1,请参阅 @Thom Kiesewetter 的回答
对于 EF Core 5,将在
IQueryable<>
上使用内置方法ToQueryString()
由于 EF 7 已重命名为 Entity Framework Core,我将总结一下 EF Core 的选项。
从IQueryable<>
记录SQL语句有3种方法:
下面是疯狂的反射代码(扩展方法):
public static class IQueryableExtensions
private static readonly TypeInfo QueryCompilerTypeInfo = typeof(QueryCompiler).GetTypeInfo();
private static readonly FieldInfo QueryCompilerField = typeof(EntityQueryProvider).GetTypeInfo().DeclaredFields.First(x => x.Name == "_queryCompiler");
private static readonly FieldInfo QueryModelGeneratorField = QueryCompilerTypeInfo.DeclaredFields.First(x => x.Name == "_queryModelGenerator");
private static readonly FieldInfo DataBaseField = QueryCompilerTypeInfo.DeclaredFields.Single(x => x.Name == "_database");
private static readonly PropertyInfo DatabaseDependenciesField = typeof(Database).GetTypeInfo().DeclaredProperties.Single(x => x.Name == "Dependencies");
public static string ToSql<TEntity>(this IQueryable<TEntity> query) where TEntity : class
var queryCompiler = (QueryCompiler)QueryCompilerField.GetValue(query.Provider);
var modelGenerator = (QueryModelGenerator)QueryModelGeneratorField.GetValue(queryCompiler);
var queryModel = modelGenerator.ParseQuery(query.Expression);
var database = (IDatabase)DataBaseField.GetValue(queryCompiler);
var databaseDependencies = (DatabaseDependencies)DatabaseDependenciesField.GetValue(database);
var queryCompilationContext = databaseDependencies.QueryCompilationContextFactory.Create(false);
var modelVisitor = (RelationalQueryModelVisitor)queryCompilationContext.CreateQueryModelVisitor();
modelVisitor.CreateQueryExecutor<TEntity>(queryModel);
var sql = modelVisitor.Queries.First().ToString();
return sql;
将此扩展方法添加到您的代码后,您可以使用如下方法:
// Build a query using Entity Framework
var query = _context.Widgets.Where(w => w.IsReal && w.Id == 42);
// Get the generated SQL
var sql = query.ToSql();
推荐人:http://rion.io/2016/10/19/accessing-entity-framework-core-queries-behind-the-scenes-in-asp-net-core/ 和 https://gist.github.com/rionmonster/2c59f449e67edf8cd6164e9fe66c545a
【讨论】:
感谢 cmets。我更新了代码,现在它应该可以与 2.1 一起使用。 @SteffenMangold 用于调试目的 :) 它的目的不是为了快速。 @RicardoPeres:不,他们引用了rion.io/2016/10/19/…,这归功于您的帖子。 @Alexei 我开始使用optionsBuilder.UseLoggerFactory(LoggerFactory);
public static readonly LoggerFactory LoggerFactory = new LoggerFactory(new[] new ConsoleLoggerProvider((_, __) => true, true) );
是因为它会生成更漂亮的sql,但不幸的是也有很多垃圾邮件。
.Net Core 3.0 和 EF Core 3.0 现已在 GA 中发布,它对方法进行了重大更改:ToSql。知道如何为 3.0 重新实现它吗?更多信息:github.com/aspnet/EntityFrameworkCore/issues/18029【参考方案3】:
对于任何只想诊断一次性失败的 EF Core 查询或类似问题并且不想更改其代码的人,有两种选择:
使用 SQL Server Management Studio (SSMS) SQL Profiler
如果您已安装 SQL Server Management Studio (SSMS),您只需从 SSMS 的“工具”菜单中fire up the SQL Profiler:
然后在 SQL Profiler 打开后启动一个新的跟踪。
然后您将能够看到来自 EF 的传入 SQL 请求,它们通常格式良好且易于阅读。
在 Visual Studio 中检查输出窗口
在我的 VS2019 副本中,使用 EF2.2 我可以更改输出窗口以显示来自 Web 服务器的输出(在顶部的“显示输出”组合中选择您的应用程序和 Web 服务器的名称)输出窗格)和传出的 SQL 也显示在那里。我检查了我的代码,据我所知,我没有做任何事情来启用它,所以我认为它必须默认这样做:
如果您想在查询中查看发送到 SQL 服务器的参数,您可以在使用 EnableSensitiveDataLogging
方法设置 DBContext 时将其打开,例如
services.AddDbContext<FusionContext>(options => options
.UseSqlServer(connectionString))
//.EnableDetailedErrors()
.EnableSensitiveDataLogging()
@Tich -- Lil3p 在 cmets 中提到,他们还需要使用项目属性页面的 a switch to turn on SQL Debugging in the Debug tab(在 LaunchSettings.json 中设置 "sqlDebugging": true
)。我检查过,我的任何项目都没有启用该功能,但如果上述方法不适合您,那可能也值得尝试。
【讨论】:
不是 Azure Sql 的选项 @batmaci 我添加了另一种可能适用于 Azure 的方法 我确实从 EF Core 获得了输出,但它没有显示它用于 @__p_0 等的变量。 @DaleyKD 如果记忆对我有用,这是一个安全问题 - 我认为 MVC 默认隐藏参数,因为它们可能包含敏感数据。我认为 MVC 的调试选项之一会导致显示参数,但我不记得是哪一个。查看我的代码,我在 Startup.Configure 中有app.UseDeveloperExceptionPage()
,在 Startup.ConfigureServices 中有 services.AddServerSideBlazor() .AddCircuitOptions(options => options.DetailedErrors = true; );
。其中之一可能会显示参数。
这个链接帮助了我 -> thecodebuzz.com/adding-logging-in-entity-framework-core.【参考方案4】:
我的看法基于@nikolay-kostov 的回答。
不同之处在于我得到的 SQL 命令是提取参数而不是硬编码的,这更符合 EF Core 向数据库发送命令的方式。另外,如果要编辑命令并将命令发送到数据库,最好使用参数。
private static class IQueryableUtils
private static readonly TypeInfo QueryCompilerTypeInfo = typeof(QueryCompiler).GetTypeInfo();
private static readonly FieldInfo QueryCompilerField = typeof(EntityQueryProvider).GetTypeInfo().DeclaredFields.First(x => x.Name == "_queryCompiler");
private static readonly FieldInfo QueryModelGeneratorField = QueryCompilerTypeInfo.DeclaredFields.First(x => x.Name == "_queryModelGenerator");
private static readonly FieldInfo queryContextFactoryField = QueryCompilerTypeInfo.DeclaredFields.First(x => x.Name == "_queryContextFactory");
private static readonly FieldInfo loggerField = QueryCompilerTypeInfo.DeclaredFields.First(x => x.Name == "_logger");
private static readonly FieldInfo DataBaseField = QueryCompilerTypeInfo.DeclaredFields.Single(x => x.Name == "_database");
private static readonly PropertyInfo DatabaseDependenciesField = typeof(Database).GetTypeInfo().DeclaredProperties.Single(x => x.Name == "Dependencies");
public static (string sql, IReadOnlyDictionary<string, object> parameters) ToSql<TEntity>(IQueryable<TEntity> query) where TEntity : class
var queryCompiler = (QueryCompiler)QueryCompilerField.GetValue(query.Provider);
var queryContextFactory = (IQueryContextFactory)queryContextFactoryField.GetValue(queryCompiler);
var logger = (Microsoft.EntityFrameworkCore.Diagnostics.IDiagnosticsLogger<DbLoggerCategory.Query>)loggerField.GetValue(queryCompiler);
var queryContext = queryContextFactory.Create();
var modelGenerator = (QueryModelGenerator)QueryModelGeneratorField.GetValue(queryCompiler);
var newQueryExpression = modelGenerator.ExtractParameters(logger, query.Expression, queryContext);
var queryModel = modelGenerator.ParseQuery(newQueryExpression);
var database = (IDatabase)DataBaseField.GetValue(queryCompiler);
var databaseDependencies = (DatabaseDependencies)DatabaseDependenciesField.GetValue(database);
var queryCompilationContext = databaseDependencies.QueryCompilationContextFactory.Create(false);
var modelVisitor = (RelationalQueryModelVisitor)queryCompilationContext.CreateQueryModelVisitor();
modelVisitor.CreateQueryExecutor<TEntity>(queryModel);
var command = modelVisitor.Queries.First().CreateDefaultQuerySqlGenerator()
.GenerateSql(queryContext.ParameterValues);
return (command.CommandText, queryContext.ParameterValues);
【讨论】:
【参考方案5】:实体框架核心 3.x
你可以通过日志获得它。
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
使用哪个工厂:
optionsBuilder.UseLoggerFactory(_loggerFactory);
来自this post
如果您想实现 ILogger,可以获取更多信息:
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
【讨论】:
【参考方案6】:添加此答案是因为此处的所有建议都与新的 EF Core 版本不同(即,此处的所有答案在 EF Core 2.2 上都已失效)。这是第一次尝试对我有用的代码,似乎与 .NET Core 版本无关(到目前为止):https://blogs.msdn.microsoft.com/dbrowne/2017/09/22/simple-logging-for-ef-core/
【讨论】:
【参考方案7】:对于带有变量的 EF Core 3.1,我在上面来自 @Thom Kiesewetter 等人的评论中链接了以下内容(基于一些 GitHub comments from halllo)。
/// <summary>
/// SQL Extension methods to get the SQL and check correctness
/// Class can be removed with EF Core 5 (https://github.com/dotnet/efcore/issues/6482#issuecomment-587605366) (although maybe variable substitution might still be necessary if we want them inline)
/// </summary>
public static class SqlExtensions
private static object Private(this object obj, string privateField) => obj?.GetType().GetField(privateField, BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(obj);
private static T Private<T>(this object obj, string privateField) => (T)obj?.GetType().GetField(privateField, BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(obj);
/// <summary>
/// Gets a SQL statement from an IQueryable
/// </summary>
/// <param name="query">The query to get the SQL statement for</param>
/// <returns>Formatted SQL statement as a string</returns>
public static string ToQueryString<TEntity>(this IQueryable<TEntity> query) where TEntity : class
using var enumerator = query.Provider.Execute<IEnumerable<TEntity>>(query.Expression).GetEnumerator();
var relationalCommandCache = enumerator.Private("_relationalCommandCache");
var selectExpression = relationalCommandCache.Private<SelectExpression>("_selectExpression");
var factory = relationalCommandCache.Private<IQuerySqlGeneratorFactory>("_querySqlGeneratorFactory");
var relationalQueryContext = enumerator.Private<RelationalQueryContext>("_relationalQueryContext");
var sqlGenerator = factory.Create();
var command = sqlGenerator.GetCommand(selectExpression);
var parametersDict = relationalQueryContext.ParameterValues;
return SubstituteVariables(command.CommandText, parametersDict);
private static string SubstituteVariables(string commandText, IReadOnlyDictionary<string, object> parametersDictionary)
var sql = commandText;
foreach (var (key, value) in parametersDictionary)
var placeHolder = "@" + key;
var actualValue = GetActualValue(value);
sql = sql.Replace(placeHolder, actualValue);
return sql;
private static string GetActualValue(object value)
var type = value.GetType();
if (type.IsNumeric())
return value.ToString();
if (type == typeof(DateTime) || type == typeof(DateTimeOffset))
switch (type.Name)
case nameof(DateTime):
return $"'(DateTime)value:u'";
case nameof(DateTimeOffset):
return $"'(DateTimeOffset)value:u'";
return $"'value'";
private static bool IsNullable(this Type type)
return
type != null &&
type.IsGenericType &&
type.GetGenericTypeDefinition() == typeof(Nullable<>);
private static bool IsNumeric(this Type type)
if (IsNullable(type))
type = Nullable.GetUnderlyingType(type);
if (type == null || type.IsEnum)
return false;
return Type.GetTypeCode(type) switch
TypeCode.Byte => true,
TypeCode.Decimal => true,
TypeCode.Double => true,
TypeCode.Int16 => true,
TypeCode.Int32 => true,
TypeCode.Int64 => true,
TypeCode.SByte => true,
TypeCode.Single => true,
TypeCode.UInt16 => true,
TypeCode.UInt32 => true,
TypeCode.UInt64 => true,
_ => false
;
这可能并不能替代所有类型,但大多数类型都已涵盖。随意扩展。
【讨论】:
【参考方案8】:对于EF Core 3.1 solution above,在使用myQueryable.Where(x => ids.Contains(x.Id))
之类的查询时,您可能会遇到System.InvalidCastException
(有关详细信息,请参见下文)。
(产生SELECT ... FROM ... WHERE ID IN (...)
形式的sql语句)
System.InvalidCastException
Message=Unable to cast object of type 'Microsoft.EntityFrameworkCore.Query.SqlExpressions.SqlParameterExpression' to type 'Microsoft.EntityFrameworkCore.Query.SqlExpressions.SqlConstantExpression'.
Source=Microsoft.EntityFrameworkCore.Relational
StackTrace:
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitIn(InExpression inExpression) in /_/src/EFCore.Relational/Query/QuerySqlGenerator.cs:line 577
at Microsoft.EntityFrameworkCore.Query.SqlExpressionVisitor.VisitExtension(Expression extensionExpression) in /_/src/EFCore.Relational/Query/SqlExpressionVisitor.cs:line 37
at System.Linq.Expressions.Expression.Accept(ExpressionVisitor visitor) in /_/src/System.Linq.Expressions/src/System/Linq/Expressions/Expression.cs:line 164
at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node) in /_/src/System.Linq.Expressions/src/System/Linq/Expressions/ExpressionVisitor.cs:line 34
为了解决这个问题,请将代码调整为:
EF Core 3.1
using System.Linq;
using System.Reflection;
using System.Collections.Generic;
using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
using Microsoft.EntityFrameworkCore.Query;
public static string ToSql<TEntity>(this IQueryable<TEntity> query) where TEntity : class
using var enumerator = query.Provider.Execute<IEnumerable<TEntity>>(query.Expression).GetEnumerator();
var relationalCommandCache = enumerator.Private("_relationalCommandCache");
var selectExpression = relationalCommandCache.Private<SelectExpression>("_selectExpression");
var factory = relationalCommandCache.Private<IQuerySqlGeneratorFactory>("_querySqlGeneratorFactory");
var relationalQueryContext = enumerator.Private<RelationalQueryContext>("_relationalQueryContext");
var parameterValueBasedSelectExpressionOptimizer = relationalCommandCache.Private<ParameterValueBasedSelectExpressionOptimizer>("_parameterValueBasedSelectExpressionOptimizer");
(selectExpression, _) = parameterValueBasedSelectExpressionOptimizer.Optimize(selectExpression, relationalQueryContext.ParameterValues);
var sqlGenerator = factory.Create();
var command = sqlGenerator.GetCommand(selectExpression);
string sql = command.CommandText;
return sql;
private static object Private(this object obj, string privateField) => obj?.GetType().GetField(privateField, BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(obj);
private static T Private<T>(this object obj, string privateField) => (T)obj?.GetType().GetField(privateField, BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(obj);
【讨论】:
【参考方案9】:对于 EF Core 3 及更高版本,EFCore.BulkExtensions 有一个 ToParametrizedSql 方法。我唯一的抱怨是它以 Microsoft.Data.SqlClient 的形式返回参数,所以如果那是我的连接类型,有时我必须将它们转换为 System.Data.SqlClient。
https://github.com/borisdj/EFCore.BulkExtensions
EFCore.BulkExtensions.IQueryableExtensions.ToParametrizedSql
【讨论】:
【参考方案10】:作为公共服务:
var someQuery = (
from projects in _context.projects
join issues in _context.issues on projects.Id equals issues.ProjectId into tmpMapp
from issues in tmpMapp.DefaultIfEmpty()
select issues
) //.ToList()
;
// string sql = someQuery.ToString();
// string sql = Microsoft.EntityFrameworkCore.IQueryableExtensions.ToSql(someQuery);
// string sql = Microsoft.EntityFrameworkCore.IQueryableExtensions1.ToSql(someQuery);
// using Microsoft.EntityFrameworkCore;
string sql = someQuery.ToSql();
System.Console.WriteLine(sql);
然后是这些扩展方法(.NET Core 1.0 的 IQueryableExtensions1,.NET Core 2.0 的 IQueryableExtensions):
using System;
using System.Linq;
using System.Reflection;
using Microsoft.EntityFrameworkCore.Internal;
using Microsoft.EntityFrameworkCore.Query;
using Microsoft.EntityFrameworkCore.Query.Internal;
using Microsoft.EntityFrameworkCore.Storage;
using Remotion.Linq.Parsing.Structure;
namespace Microsoft.EntityFrameworkCore
// https://***.com/questions/1412863/how-do-i-view-the-sql-generated-by-the-entity-framework
// http://rion.io/2016/10/19/accessing-entity-framework-core-queries-behind-the-scenes-in-asp-net-core/
public static class IQueryableExtensions
private static readonly TypeInfo QueryCompilerTypeInfo = typeof(QueryCompiler).GetTypeInfo();
private static readonly FieldInfo QueryCompilerField = typeof(EntityQueryProvider).GetTypeInfo().DeclaredFields
.First(x => x.Name == "_queryCompiler");
private static readonly PropertyInfo NodeTypeProviderField =
QueryCompilerTypeInfo.DeclaredProperties.Single(x => x.Name == "NodeTypeProvider");
private static readonly MethodInfo CreateQueryParserMethod =
QueryCompilerTypeInfo.DeclaredMethods.First(x => x.Name == "CreateQueryParser");
private static readonly FieldInfo DataBaseField =
QueryCompilerTypeInfo.DeclaredFields.Single(x => x.Name == "_database");
private static readonly PropertyInfo DatabaseDependenciesField =
typeof(Database).GetTypeInfo().DeclaredProperties.Single(x => x.Name == "Dependencies");
public static string ToSql<TEntity>(this IQueryable<TEntity> query) where TEntity : class
if (!(query is EntityQueryable<TEntity>) && !(query is InternalDbSet<TEntity>))
throw new ArgumentException("Invalid query");
var queryCompiler = (QueryCompiler) QueryCompilerField.GetValue(query.Provider);
var nodeTypeProvider = (INodeTypeProvider) NodeTypeProviderField.GetValue(queryCompiler);
var parser = (IQueryParser) CreateQueryParserMethod.Invoke(queryCompiler, new object[] nodeTypeProvider);
var queryModel = parser.GetParsedQuery(query.Expression);
var database = DataBaseField.GetValue(queryCompiler);
var databaseDependencies = (DatabaseDependencies) DatabaseDependenciesField.GetValue(database);
var queryCompilationContext = databaseDependencies.QueryCompilationContextFactory.Create(false);
var modelVisitor = (RelationalQueryModelVisitor) queryCompilationContext.CreateQueryModelVisitor();
modelVisitor.CreateQueryExecutor<TEntity>(queryModel);
var sql = modelVisitor.Queries.First().ToString();
return sql;
public class IQueryableExtensions1
private static readonly TypeInfo QueryCompilerTypeInfo = typeof(QueryCompiler).GetTypeInfo();
private static readonly FieldInfo QueryCompilerField = typeof(EntityQueryProvider).GetTypeInfo()
.DeclaredFields
.First(x => x.Name == "_queryCompiler");
private static readonly PropertyInfo NodeTypeProviderField =
QueryCompilerTypeInfo.DeclaredProperties.Single(x => x.Name == "NodeTypeProvider");
private static readonly MethodInfo CreateQueryParserMethod =
QueryCompilerTypeInfo.DeclaredMethods.First(x => x.Name == "CreateQueryParser");
private static readonly FieldInfo DataBaseField =
QueryCompilerTypeInfo.DeclaredFields.Single(x => x.Name == "_database");
private static readonly FieldInfo QueryCompilationContextFactoryField = typeof(Database).GetTypeInfo()
.DeclaredFields.Single(x => x.Name == "_queryCompilationContextFactory");
public static string ToSql<TEntity>(IQueryable<TEntity> query) where TEntity : class
if (!(query is EntityQueryable<TEntity>) && !(query is InternalDbSet<TEntity>))
throw new ArgumentException("Invalid query");
var queryCompiler = (IQueryCompiler) QueryCompilerField.GetValue(query.Provider);
var nodeTypeProvider = (INodeTypeProvider) NodeTypeProviderField.GetValue(queryCompiler);
var parser =
(IQueryParser) CreateQueryParserMethod.Invoke(queryCompiler, new object[] nodeTypeProvider);
var queryModel = parser.GetParsedQuery(query.Expression);
var database = DataBaseField.GetValue(queryCompiler);
var queryCompilationContextFactory =
(IQueryCompilationContextFactory) QueryCompilationContextFactoryField.GetValue(database);
var queryCompilationContext = queryCompilationContextFactory.Create(false);
var modelVisitor = (RelationalQueryModelVisitor) queryCompilationContext.CreateQueryModelVisitor();
modelVisitor.CreateQueryExecutor<TEntity>(queryModel);
var sql = modelVisitor.Queries.First().ToString();
return sql;
【讨论】:
使用最新的 EF Core 2.1.1 ,这不再起作用。私有静态只读 PropertyInfo NodeTypeProviderField = QueryCompilerTypeInfo.DeclaredProperties.Single(x => x.Name == "NodeTypeProvider"); 时出错 @Stef Heyenrath:我认为我的回答清楚地说明了 .NET Core 1.0 和 2.0,而不是 2.1 或 2.2。其他人已经给出了 2.2、3.0 和 3.1 的代码。在我写这个答案的时候,.NET Core 2.1 还没有发布。它对 .NET Core 2.0 和 1.0 完全有效以上是关于从 Entity Framework Core IQueryable<T> 获取 SQL 代码的主要内容,如果未能解决你的问题,请参考以下文章
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