fail: 2023/7/14 14:31:33.417 CoreEventId.QueryIterationFailed[10100] (Microsoft.EntityFrameworkCore.Query) An exception occurred while iterating over the results of a query for context type 'iMES.Core.EFDbContext.SysDbContext'. System.InvalidOperationException: There is already an open DataReader associated with this Connection which must be closed first. at Microsoft.Data.SqlClient.SqlInternalConnectionTds.ValidateConnectionForExecute(SqlCommand command) at Microsoft.Data.SqlClient.SqlConnection.ValidateConnectionForExecute(String method, SqlCommand command) at Microsoft.Data.SqlClient.SqlCommand.ValidateCommand(Boolean isAsync, String method) at Microsoft.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry, String method) at Microsoft.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) at Microsoft.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior) at Microsoft.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReader(RelationalCommandParameterObject parameterObject) at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.InitializeReader(Enumerator enumerator) at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.<>c.<MoveNext>b__21_0(DbContext _, Enumerator enumerator) at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded) at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext()
时间: 2024-04-18 22:31:02 浏览: 9
根据您提供的信息,出现了一个异常,提示已经有一个与该连接关联的打开的 DataReader,必须先关闭它。
这个问题通常是由于在使用 Entity Framework 进行查询时,存在未关闭的 DataReader 导致的。DataReaders 是用于读取数据库查询结果的对象,在使用完毕后需要显式地关闭。
要解决这个问题,您可以尝试以下几点:
1. 确保在使用完 DataReader 后,及时调用其 Close() 或 Dispose() 方法来关闭它。可以使用 using 语句来自动处理这个操作,确保 DataReader 在使用完毕后被正确关闭。
2. 检查代码中是否存在嵌套的查询或循环查询,确保每个查询都正确关闭其对应的 DataReader。
3. 如果您的代码中使用了多个数据库连接对象,确保每个连接对象都能正确地关闭和释放资源。
4. 如果您使用的是异步查询,需要注意在异步操作完成后关闭 DataReader。
需要注意的是,以上建议是一般情况下解决该异常的方法。根据具体的代码和业务逻辑,您可能需要进一步检查和调整代码以确保 DataReader 的正确关闭。
希望以上建议对解决您的问题有所帮助!如果您需要更详细的帮助,请提供更多关于您的代码和查询的信息。
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