关于EF6的记录Sql语句 与 EntityFramework.Extend 的诟病

1、关于EF6的记录Sql语句，一个老生长谈的问题。 他生成的sql语句实在是烂，大家都这样说

2、EF6 更新删除不方便，没有批量操作。所以，有人出了EF6.Extend  大家用起来也很爽

基于以上两点，我也尝试着使用 EF6.Extend 。本以为可以很好的，很美好。没有想到我遇到了一个大问题。

我需要 通过程序记录 EF执行的Sql语句，当然也包括 EF6.Extend 执行的Sql语句。（不是通过SqlProfiler）

在网上查找，发现 了一篇文章，我就这样抄下来了。（太匆忙解决问题，忘记了哪一篇）

继承了 System.Data.Entity.Infrastructure.Interception.DbCommandInterceptor  ，实现相关方法。  然后在Main方法（程序入口）进行添加  DbInterception.Add(new EFIntercepterLogging());

 using System;
 using System.Collections.Generic;
 using System.Data.Entity.Infrastructure.Interception;
 using System.Diagnostics;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;

 namespace EF_Sqlite
 {
     class EFIntercepterLogging : DbCommandInterceptor
     {
         private readonly Stopwatch _stopwatch = new Stopwatch();
         public override void ScalarExecuting(System.Data.Common.DbCommand command, DbCommandInterceptionContext<object> interceptionContext)
         {
             base.ScalarExecuting(command, interceptionContext);
             _stopwatch.Restart();
         }
         public override void ScalarExecuted(System.Data.Common.DbCommand command, DbCommandInterceptionContext<object> interceptionContext)
         {
             _stopwatch.Stop();
             if (interceptionContext.Exception != null)
             {
                 Trace.TraceError("Exception:{1} \r\n --> Error executing command: {0}", command.CommandText, interceptionContext.Exception.ToString());
             }
             else
             {
                 string txt=string.Format("\r\n执行时间:{0} 毫秒\r\n-->ScalarExecuted.Command:{1}\r\n", _stopwatch.ElapsedMilliseconds, command.CommandText);
                 Console.WriteLine(txt);
                 Trace.TraceInformation(txt);
             }
             base.ScalarExecuted(command, interceptionContext);
         }
         public override void NonQueryExecuting(System.Data.Common.DbCommand command, DbCommandInterceptionContext<int> interceptionContext)
         {
             base.NonQueryExecuting(command, interceptionContext);
             _stopwatch.Restart();
         }
         public override void NonQueryExecuted(System.Data.Common.DbCommand command, DbCommandInterceptionContext<int> interceptionContext)
         {

             _stopwatch.Stop();
             if (interceptionContext.Exception != null)
             {
                 Trace.TraceError("Exception:{1} \r\n --> Error executing command:\r\n {0}", command.CommandText, interceptionContext.Exception.ToString());
             }
             else
             {   

                 string txt = string.Format("\r\n执行时间:{0} 毫秒\r\n-->ScalarExecuted.Command:{1}\r\n", _stopwatch.ElapsedMilliseconds, command.CommandText);
                 Console.WriteLine(txt);
                 Trace.TraceInformation(txt);
             }
             base.NonQueryExecuted(command, interceptionContext);
         }
         public override void ReaderExecuting(System.Data.Common.DbCommand command, DbCommandInterceptionContext<System.Data.Common.DbDataReader> interceptionContext)
         {
             base.ReaderExecuting(command, interceptionContext);
             _stopwatch.Restart();
         }
         public override void ReaderExecuted(System.Data.Common.DbCommand command, DbCommandInterceptionContext<System.Data.Common.DbDataReader> interceptionContext)
         {
             _stopwatch.Stop();
             if (interceptionContext.Exception != null)
             {
                 Trace.TraceError("Exception:{1} \r\n --> Error executing command:\r\n {0}", command.CommandText, interceptionContext.Exception.ToString());
             }
             else
             {
                 string txt = string.Format("\r\n执行时间:{0} 毫秒\r\n-->ScalarExecuted.Command:{1}\r\n", _stopwatch.ElapsedMilliseconds, command.CommandText);
                 Console.WriteLine(txt);
                 Trace.TraceInformation(txt);
             }
             base.ReaderExecuted(command, interceptionContext);
         }

     }
 }

日志记录类完整代码

通过EF正常的操作是可以记录到SQL语句的，而通过EF.Extend执行的删除操作是无法获取sql的。我想，是不是我写错了，可网上根本没有关于EF.Extend 记录生成SQL的只言片语，可能大家都没有遇到这样的问题。

只能硬着头皮，翻源码。

经过翻看EF.Extend的源码，发现他是直接用Command执行的sql，再翻 EF的源码发现，EF是绕了很大一圈来执行的SQL

找到EF的这里，我明白了

 public virtual int NonQuery(DbCommand command, DbCommandInterceptionContext interceptionContext)
 {
 Check.NotNull(command, "command");
 Check.NotNull(interceptionContext, "interceptionContext");

 return _internalDispatcher.Dispatch(
 command,
 (t, c) => t.ExecuteNonQuery(),
 new DbCommandInterceptionContext<int>(interceptionContext),
 (i, t, c) => i.NonQueryExecuting(t, c),
 (i, t, c) => i.NonQueryExecuted(t, c));
 }

EF的执行代码

而，EF.Extend的代码是这样写的

 private int InternalDelete<TEntity>(ObjectContext objectContext, EntityMap entityMap, ObjectQuery<TEntity> query)
             where TEntity : class
 #endif
         {
             DbConnection deleteConnection = null;
             DbTransaction deleteTransaction = null;
             DbCommand deleteCommand = null;
             bool ownConnection = false;
             bool ownTransaction = false;

             try
             {
                 // get store connection and transaction
                 var store = GetStore(objectContext);
                 deleteConnection = store.Item1;
                 deleteTransaction = store.Item2;

                 if (deleteConnection.State != ConnectionState.Open)
                 {
                     deleteConnection.Open();
                     ownConnection = true;
                 }

                 if (deleteTransaction == null)
                 {
                     deleteTransaction = deleteConnection.BeginTransaction();
                     ownTransaction = true;
                 }

                 deleteCommand = deleteConnection.CreateCommand();
                 deleteCommand.Transaction = deleteTransaction;
                 if (objectContext.CommandTimeout.HasValue)
                     deleteCommand.CommandTimeout = objectContext.CommandTimeout.Value;

                 var innerSelect = GetSelectSql(query, entityMap, deleteCommand);

                 var sqlBuilder = new StringBuilder(innerSelect.Length * );

                 sqlBuilder.Append("DELETE ");
                 sqlBuilder.Append(entityMap.TableName);
                 sqlBuilder.AppendLine();

                 sqlBuilder.AppendFormat("FROM {0} AS j0 INNER JOIN (", entityMap.TableName);
                 sqlBuilder.AppendLine();
                 sqlBuilder.AppendLine(innerSelect);
                 sqlBuilder.Append(") AS j1 ON (");

                 bool wroteKey = false;
                 foreach (var keyMap in entityMap.KeyMaps)
                 {
                     if (wroteKey)
                         sqlBuilder.Append(" AND ");

                     sqlBuilder.AppendFormat("j0.[{0}] = j1.[{0}]", keyMap.ColumnName);
                     wroteKey = true;
                 }
                 sqlBuilder.Append(")");

                 deleteCommand.CommandText = sqlBuilder.ToString();

 #if NET45
                 int result = async
                     ? await deleteCommand.ExecuteNonQueryAsync().ConfigureAwait(false)
                     : deleteCommand.ExecuteNonQuery();
 #else
                 int result = deleteCommand.ExecuteNonQuery();
 #endif
                 // only commit if created transaction
                 if (ownTransaction)
                     deleteTransaction.Commit();

                 return result;
             }
             finally
             {
                 if (deleteCommand != null)
                     deleteCommand.Dispose();

                 if (deleteTransaction != null && ownTransaction)
                     deleteTransaction.Dispose();

                 if (deleteConnection != null && ownConnection)
                     deleteConnection.Close();
             }
         }

EF.Extend的执行代码

经过分析，是这个道理，按照这个逻辑，EF.Extend没有按照EF的逻辑写，所以，他不能通过这种方式记录Sql。

恍然大悟后，我这样执行的Sql

System.Data.Common.DbConnection con = t.Database.Connection;
System.Data.Common.DbCommand command = con.CreateCommand();
con.Open();
command.CommandText = "delete from area where 1=2 and 4=9";
DbInterception.Dispatch.Command.NonQuery(command, new DbCommandInterceptionContext());

EF 自定义的SQL执行

就这样，我 通过统一的方式，获取到了我自己执行的Sql语句，和EF执行的Sql语句

本来是打算用EF.Extend的，看到这里，我决定不用了，有点杀鸡用牛刀。（其实，EF.Extend 不仅扩展了修改和删除的方法，还扩展了 EF没有的二级缓存，等等。如果只是用到修改删除的扩展方法，那可以放弃Extend了。）

修改后的DLL文件