通过游标从mySQL中选择记录将返回None对象

Question

我正在使用mysqlconnector在python 3.x中编写脚本。 我现在想要实现的是检查我的数据库中是否有记录，这可能与我正在分析的记录重复。 我提出了这样的代码：

SELECT op.OrganisationID
    , (CASE WHEN ProductPAID = 5 THEN op.PersonnelID ELSE NULL END) AS [if not ProductPAID =5]
    , t.Name
    , p.FirstName
    , p.MiddleName
    , p.LastName
    , op.ActualJobTitle
    , (CASE WHEN ProductPAID < 3 THEN ph.Number ELSE NULL END) AS [if ProductPAID <3]
    , (CASE WHEN ProductPAID = 2 OR ProductPAID = 5 THEN e.Email ELSE NULL END) AS [if ProductPAID =2 or 5]
    , p.ProductDPAID
    , dpa.Name
FROM DB.OrganisationPersonnel op
JOIN DB.Person p ON op.PersonnelID = p.ID
JOIN DB.Title t ON p.TitleID = t.ID
JOIN DB.ProductDPA dpa ON p.ProductDPAID = dpa.ID
LEFT JOIN DB.Email e ON op.EmailID = e.ID
LEFT JOIN DB.Phone ph ON op.PhoneID = op.PhoneID
WHERE op.EmployedToDate IS NULL
ORDER BY op.OrganisationID;

虽然我仍然将isDuplicate作为None对象。我试图通过 cursor.statement 检查传递给我的数据库的语句：事实证明，在脚本中我得到无obj，而在db中传递查询工作正常。 我也尝试了 SELECT COUNT（1）FROM db_name ，这也给了我不同的结果。

我没有想法：也许你们可以帮助我？

更新

对我有用的解决方案是：

def fill_data(self, db_name, data):
    cursor = self.cnx.cursor(buffered=True)
    isDuplicate = cursor.execute(("SELECT destination FROM {0} WHERE destination = '{1}';")
                                 .format(db_name, data['destination']))

    print(cursor.statement)
    self.commit()
    print(isDuplicate is None)

所以在一天结束时，一切都是从光标中获取数据：）

Answer 1

您的问题可能与您使用org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:compileReleaseJavaWithJavac'. at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:100) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:70) at org.gradle.api.internal.tasks.execution.OutputDirectoryCreatingTaskExecuter.execute(OutputDirectoryCreatingTaskExecuter.java:51) at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:62) at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54) at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:60) at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:97) at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:87) at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:52) at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52) at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54) at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43) at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34) at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:248) at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336) at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328) at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199) at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110) at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:241) at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:230) at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.processTask(DefaultTaskPlanExecutor.java:123) at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.access$200(DefaultTaskPlanExecutor.java:79) at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:104) at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:98) at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:626) at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:581) at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:98) at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java:59) at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:128) at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:37) at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:37) at org.gradle.execution.DefaultBuildExecuter.access$000(DefaultBuildExecuter.java:23) at org.gradle.execution.DefaultBuildExecuter$1.proceed(DefaultBuildExecuter.java:43) at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:46) at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:37) at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:30) at org.gradle.initialization.DefaultGradleLauncher$ExecuteTasks.run(DefaultGradleLauncher.java:314) at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336) at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328) at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199) at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110) at org.gradle.initialization.DefaultGradleLauncher.runTasks(DefaultGradleLauncher.java:204) at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:134) at org.gradle.initialization.DefaultGradleLauncher.executeTasks(DefaultGradleLauncher.java:109) at org.gradle.internal.invocation.GradleBuildController$1.call(GradleBuildController.java:78) at org.gradle.internal.invocation.GradleBuildController$1.call(GradleBuildController.java:75) at org.gradle.internal.work.DefaultWorkerLeaseService.withLocks(DefaultWorkerLeaseService.java:152) at org.gradle.internal.invocation.GradleBuildController.doBuild(GradleBuildController.java:100) at org.gradle.internal.invocation.GradleBuildController.run(GradleBuildController.java:75) at org.gradle.tooling.internal.provider.runner.BuildModelActionRunner.run(BuildModelActionRunner.java:53) at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35) at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35) at org.gradle.tooling.internal.provider.ValidatingBuildActionRunner.run(ValidatingBuildActionRunner.java:32) at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner$1.run(RunAsBuildOperationBuildActionRunner.java:43) at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336) at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328) at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199) at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110) at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.run(RunAsBuildOperationBuildActionRunner.java:40) at org.gradle.tooling.internal.provider.SubscribableBuildActionRunner.run(SubscribableBuildActionRunner.java:51) at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:47) at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:30) at org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:39) at org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:25) at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:80) at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:53) at org.gradle.tooling.internal.provider.ServicesSetupBuildActionExecuter.execute(ServicesSetupBuildActionExecuter.java:57) at org.gradle.tooling.internal.provider.ServicesSetupBuildActionExecuter.execute(ServicesSetupBuildActionExecuter.java:32) at org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:36) at org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:25) at org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:43) at org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:29) at org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:69) at org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:30) at org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:59) at org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:44) at org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:45) at org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:30) at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:67) at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122) at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:37) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122) at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:26) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122) at org.gradle.launcher.daemon.server.exec.RequestStopIfSingleUsedDaemon.execute(RequestStopIfSingleUsedDaemon.java:34) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122) at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:74) at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:72) at org.gradle.util.Swapper.swap(Swapper.java:38) at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:72) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122) at org.gradle.launcher.daemon.server.exec.LogAndCheckHealth.execute(LogAndCheckHealth.java:55) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122) at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:62) at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122) at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:82) at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122) at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:50) at org.gradle.launcher.daemon.server.DaemonStateCoordinator$1.run(DaemonStateCoordinator.java:295) at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63) at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55) at java.lang.Thread.run(Thread.java:748) Caused by: org.gradle.api.internal.tasks.compile.CompilationFailedException: Compilation failed; see the compiler error output for details. at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:50) at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:35) at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:98) at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:51) at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:37) at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:35) at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:25) at org.gradle.api.internal.tasks.compile.incremental.IncrementalCompilationFinalizer.execute(IncrementalCompilationFinalizer.java:39) at org.gradle.api.internal.tasks.compile.incremental.IncrementalCompilationFinalizer.execute(IncrementalCompilationFinalizer.java:24) at org.gradle.api.tasks.compile.JavaCompile.performCompilation(JavaCompile.java:207) at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:133) at com.android.build.gradle.tasks.factory.AndroidJavaCompile.compile(AndroidJavaCompile.java:125) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73) at org.gradle.api.internal.project.taskfactory.IncrementalTaskAction.doExecute(IncrementalTaskAction.java:46) at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:39) at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:26) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.run(ExecuteActionsTaskExecuter.java:121) at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336) at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328) at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199) at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:110) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:92) ... 107 more method的方式有关。

尝试进行一些更改，看看打印出来的内容：

execute()

Why should I provide query parameters this way?（文章在def fill_data(self, db_name, data): cursor = self.cnx.cursor(buffered=True) q = 'SELECT count(*) FROM {} WHERE destination = %s'.format(db_name) duplicate_count = cursor.execute(q, (data['destination'], )).fetchall() print(duplicate_count) ，但核心原则与psql中相同）

更新

如果您仍在接收mysql，则错误可能在此处：

"NoneType" object has no atribute "fetchall"

您似乎根本没有创建cursor = self.cnx.cursor(buffered=True) 。如果您发布一些关于cursor创建的代码，我可以看看它。