Duplicate entry '???' for key 'unq_lwr_username'

[doushuo]

2019-10-16 20:21:33,984 ERROR [Long running task: Importing data] [confluence.importexport.actions.ImportLongRunningTask] runInternal Failure during import
-- url: /longrunningtaskxml.action | referer: http://192.168.9.159:8090/admin/restore-local-file.action | traceId: 205f53eb7420b3eb | userName: admin | action: longrunningtaskxml
com.atlassian.confluence.importexport.ImportExportException: com.atlassian.confluence.importexport.ImportExportException: Unable to complete import because the data does not match the constraints in the Confluence schema. Cause: MySQLIntegrityConstraintViolationException: Duplicate entry '???' for key 'unq_lwr_username'
at com.atlassian.confluence.importexport.xmlimport.BackupImporter.importEntities(BackupImporter.java:406)
at com.atlassian.confluence.importexport.xmlimport.BackupImporter.importEverything(BackupImporter.java:367)
at com.atlassian.confluence.importexport.xmlimport.FileBackupImporter.importEverything(FileBackupImporter.java:169)
at com.atlassian.confluence.importexport.xmlimport.BackupImporter$1.doInTransactionWithoutResult(BackupImporter.java:259)
at org.springframework.transaction.support.TransactionCallbackWithoutResult.doInTransaction(TransactionCallbackWithoutResult.java:36)
at com.atlassian.confluence.importexport.xmlimport.RestorePluginStateStoreTransactionCallbackDecorator.doInTransaction(RestorePluginStateStoreTransactionCallbackDecorator.java:47)
at com.atlassian.confluence.importexport.xmlimport.RestoreBandanaValuesTransactionCallbackDecorator.doInTransaction(RestoreBandanaValuesTransactionCallbackDecorator.java:50)
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140)
at com.atlassian.confluence.importexport.xmlimport.BackupImporter.doImportInternal(BackupImporter.java:221)
at com.atlassian.confluence.importexport.Importer.doImport(Importer.java:73)
at com.atlassian.confluence.importexport.DefaultImportExportManager.performImportInternal(DefaultImportExportManager.java:118)
at com.atlassian.confluence.importexport.DefaultImportExportManager.doPerformImport(DefaultImportExportManager.java:106)
at com.atlassian.confluence.importexport.DefaultImportExportManager.performImport(DefaultImportExportManager.java:101)
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.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:343)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:295)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)

I performed a manual upgrade on version 6.11 to update to version 7.0.2, and then manually backed up the XML files on version 7.0.2.

When I restored the XML backup file on the clean Data Center7.0.2 version, the above error occurred. Before that, I consulted the user_mapping table in mysql, and found that the values of username and lower_username fields were unique. The duplicate fields had been modified before the XML backup.

For help! thank you

[doushuo]

Oh,,,,,,Such a low-level error, I should think is the problem of mysql coding, because there is a question mark in the error message!

（The character_set_server value defaults to Latin characters, which I did not change to utf8.）

MariaDB [(none)]> show variables like 'character%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | latin |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)

MariaDB [(none)]>