如何查看实体框架生成的SQL ?
(在我的特殊情况下，我使用mysql提供商-如果它重要)
当前回答
Necromancing。 当搜索任何。net框架的解决方案时，这个页面是第一个搜索结果，所以这里作为一个公共服务，它是如何在EntityFrameworkCore(用于。net Core 1和2)中完成的:
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);
然后这些扩展方法(IQueryableExtensions1用于。net Core 1.0, IQueryableExtensions用于。net Core 2.0):
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://stackoverflow.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;
}
}
}
其他回答
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
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/
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;
}
}
}
Necromancing。 当搜索任何。net框架的解决方案时，这个页面是第一个搜索结果，所以这里作为一个公共服务，它是如何在EntityFrameworkCore(用于。net Core 1和2)中完成的:
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);
然后这些扩展方法(IQueryableExtensions1用于。net Core 1.0, IQueryableExtensions用于。net Core 2.0):
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://stackoverflow.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;
}
}
}
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。
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