自发发生的 Linq IEnumerable 错误
Linq IEnumerable Error which occurs spontaneously
我在执行 Linq 查询然后将其转换为 List 对象时遇到了这个问题。让我补充一点，这个错误只是有时会发生，而且会在生产中发生。当 IEnumerable 对象转换为 List 时，将引发错误。我设置了一个记录器，这是异常类型、堆栈跟踪和内部异常。任何关于如何重构这段代码以使其更稳定的想法都将不胜感激。这是抛出错误的代码
var isMember = db.DN2_Member.Where(m =>
m.Partner_Contract_Nbr.ToLower() == member.DentalMemberId.ToLower()
&& m.Mbr_First_Nm.ToLower() == member.DentalMemberFirstName.ToLower()
//&& m.Mbr_Mid_Nm.ToLower().Trim() == memberMiddleName.ToLower()
&& m.Mbr_Last_Nm.ToLower() == member.DentalMemberLastName.ToLower()
&& m.DW_Rec_End_Dt == null
&& m.Mbr_Suc_Title.ToLower() == membersuffix.ToLower().Replace(".", ""));
//Forces the query to evaluate to a definitive collection; necessary for querying it further
var memberList = isMember.ToList();
第 88 行是 var memberList = isMember.ToList();
这是异常详情。
Exception Type: An error occurred while executing the command
definition. See the inner exception for details.
Stack Trace: at
System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand
entityCommand, CommandBehavior behavior) at
System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext
context, ObjectParameterCollection parameterValues) at
System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1
func, IDbExecutionStrategy executionStrategy, Boolean
startLocalTransaction, Boolean releaseConnectionOnSuccess) at
System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClass3.b__1()
at
System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1
operation) at
System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1
forMergeOption) at
System.Data.Entity.Core.Objects.ObjectQuery`1.b__0()
at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext() at
System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) at
System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source) at
DentalTHSEnrollmentService.WebHost.THSService.GetMember(DentalMember
member) in
e:\GoAgent\pipelines\DentalTHSEnrollmentService_Master\product\app\DentalTHSEnrollmentService.WebHost\THSService.svc.cs:line
88
Inner Exception:
System.Data.Entity.Core.EntityCommandExecutionException: An error
occurred while executing the command definition. See the inner
exception for details. ---> System.Data.SqlClient.SqlException:
Timeout expired. The timeout period elapsed prior to completion of the
operation or the server is not responding. --->
System.ComponentModel.Win32Exception: The wait operation timed out ---
End of inner exception stack trace --- at
System.Data.SqlClient.SqlConnection.OnError(SqlException exception,
Boolean breakConnection, Action`1 wrapCloseInAction) at
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject
stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at
System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior,
SqlCommand cmdHandler, SqlDataReader dataStream,
BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject
stateObj, Boolean& dataReady) at
System.Data.SqlClient.SqlDataReader.TryConsumeMetaData() at
System.Data.SqlClient.SqlDataReader.get_MetaData() at
System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds,
RunBehavior runBehavior, String resetOptionsString) at
System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior
cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean
async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader
ds) at
System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior
cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String
method, TaskCompletionSource`1 completion, Int32 timeout, Task& task,
Boolean asyncWrite) at
System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior
cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String
method) at
System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior
behavior, String method) at
System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior
behavior) at
System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget
target, Func`3 operation, TInterceptionContext interceptionContext,
Action`3 executing, Action`3 executed) at
System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand
command, DbCommandInterceptionContext interceptionContext) at
System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand
entityCommand, CommandBehavior behavior) --- End of inner exception
stack trace --- at
System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand
entityCommand, CommandBehavior behavior) at
System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext
context, ObjectParameterCollection parameterValues) at
System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1
func, IDbExecutionStrategy executionStrategy, Boolean
startLocalTransaction, Boolean releaseConnectionOnSuccess) at
System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClass3.b__1()
at
System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1
operation) at
System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1
forMergeOption) at
System.Data.Entity.Core.Objects.ObjectQuery`1.b__0()
at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext() at
System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) at
System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source) at
DentalTHSEnrollmentService.WebHost.THSService.GetMember(DentalMember
member) in
e:\GoAgent\pipelines\DentalTHSEnrollmentService_Master\product\app\DentalTHSEnrollmentService.WebHost\THSService.svc.cs:line
88
您的错误信息的关键是：
System.Data.SqlClient.SqlException: Timeout expired. The timeout
period elapsed prior to completion of the operation or the server is
not responding.
基本上，您的 sql 查询到 运行 的时间比您的命令超时时间长。您应该为 table / table 添加索引以帮助提高性能。
我在执行 Linq 查询然后将其转换为 List 对象时遇到了这个问题。让我补充一点，这个错误只是有时会发生，而且会在生产中发生。当 IEnumerable 对象转换为 List 时，将引发错误。我设置了一个记录器，这是异常类型、堆栈跟踪和内部异常。任何关于如何重构这段代码以使其更稳定的想法都将不胜感激。这是抛出错误的代码
var isMember = db.DN2_Member.Where(m =>
m.Partner_Contract_Nbr.ToLower() == member.DentalMemberId.ToLower()
&& m.Mbr_First_Nm.ToLower() == member.DentalMemberFirstName.ToLower()
//&& m.Mbr_Mid_Nm.ToLower().Trim() == memberMiddleName.ToLower()
&& m.Mbr_Last_Nm.ToLower() == member.DentalMemberLastName.ToLower()
&& m.DW_Rec_End_Dt == null
&& m.Mbr_Suc_Title.ToLower() == membersuffix.ToLower().Replace(".", ""));
//Forces the query to evaluate to a definitive collection; necessary for querying it further
var memberList = isMember.ToList();
第 88 行是 var memberList = isMember.ToList();
这是异常详情。
Exception Type: An error occurred while executing the command definition. See the inner exception for details.
Stack Trace: at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext context, ObjectParameterCollection parameterValues) at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess) at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClass3.b__1() at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation) at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption) at System.Data.Entity.Core.Objects.ObjectQuery`1.b__0() at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext() at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source) at DentalTHSEnrollmentService.WebHost.THSService.GetMember(DentalMember member) in e:\GoAgent\pipelines\DentalTHSEnrollmentService_Master\product\app\DentalTHSEnrollmentService.WebHost\THSService.svc.cs:line 88
Inner Exception: System.Data.Entity.Core.EntityCommandExecutionException: An error occurred while executing the command definition. See the inner exception for details. ---> System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. ---> System.ComponentModel.Win32Exception: The wait operation timed out --- End of inner exception stack trace --- at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.SqlDataReader.TryConsumeMetaData() at System.Data.SqlClient.SqlDataReader.get_MetaData() at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader ds) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) at System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed) at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext) at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) --- End of inner exception stack trace --- at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext context, ObjectParameterCollection parameterValues) at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess) at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClass3.b__1() at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation) at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption) at System.Data.Entity.Core.Objects.ObjectQuery`1.b__0() at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext() at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source) at DentalTHSEnrollmentService.WebHost.THSService.GetMember(DentalMember member) in e:\GoAgent\pipelines\DentalTHSEnrollmentService_Master\product\app\DentalTHSEnrollmentService.WebHost\THSService.svc.cs:line 88
您的错误信息的关键是：
System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
基本上，您的 sql 查询到 运行 的时间比您的命令超时时间长。您应该为 table / table 添加索引以帮助提高性能。