【windows】open database crash

[baneyue]

The following error occurs occasionally when opening dB on windows. However, it can be accessed by changing the external SQLite tool of DB

══╡ EXCEPTION CAUGHT BY FLUTTER FRAMEWORK ╞══════════════════════
The following _CastError was thrown:
type 'Null' is not a subtype of type 'String' in type cast

When the exception was thrown, this was the stack:
#0 SqfliteIsolate.handle (package:sqflite_common_ffi/src/isolate.dart:41:33)

#1 FfiMethodCallHandler._isolateHandle (package:sqflite_common_ffi/src/database_factory_ffi.dart:95:12)

#2 FfiMethodCallHandler.handleInIsolate (package:sqflite_common_ffi/src/database_factory_ffi.dart:51:20)

#3 _SqfliteDatabaseFactoryImpl.invokeMethod (package:sqflite_common/src/mixin/factory.dart:20:8)

#4 SqfliteDatabaseMixin.openDatabase (package:sqflite_common/src/database_mixin.dart:556:9)

#5 SqfliteDatabaseMixin.doOpen (package:sqflite_common/src/database_mixin.dart:649:22)

#6 SqfliteDatabaseOpenHelper.openDatabase (package:sqflite_common/src/database.dart:44:7)

#7 SqfliteDatabaseFactoryMixin.openDatabase. (package:sqflite_common/src/factory_mixin.dart:111:18)

#8 ReentrantLock.synchronized. (package:synchronized/src/reentrant_lock.dart:37:18)

#9 BasicLock.synchronized (package:synchronized/src/basic_lock.dart:33:16)

#10 queryAllUser_labelid (package:wxwork_helper/demo/MainViewPage/Tool/MessageQueryDBTool.dart:247:19)

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[alextekartik]

Thanks for the report. I you can manage to show the message where it fails (and the sql statement executed); it would help a a lot in reproducing on my side

[baneyue]

only when open database。the database is exists and can open with other sqlite db tools.

[baneyue]

@alextekartik Is there any progress on this issue

[alextekartik]

I could not manage to reproduce. What could help to try on your side:

• Add some print before to see your path. Build your path (absolute? or relative?) using join only and not a mix of join and \\:

  // instead of var path = join(WechatDbPathString + currentUserModel.vid + '\\', 'user.db');
  var path = join(WechatDbPathString + currentUserModel.vid, 'user.db');
  // instead of  join(DatasavePathString + `\\`, id);
  var path = join(DatasavePathString, id);
  // print for debugging
  print('opening $path');

• You might try to use path_provider for setting the default location of your database.
• Check the database (PRAGMA integrity_check) using desktop tools (https://sqliteviewer.com/blog/database-disk-image-malformed)
• Or good if you can share your database so I can try to open it in a unit test.
• You can add extra logs from sqflite itself to see if more info get printed that help analyzing the issue.
• If you can debug the crash, good if you code see the content of the error map in your first picture (error is Map). It seems to be a map without some expected keys), maybe its content will help.
• Try to use flutter_lints. You are missing some await (setDatabasesPath) and here the content of the path is important to see (it should be absolute).
• Ah also in your report, good if you can copy the code and paste between triple-ticks instead of pasting images. It is easier to make comment on code.

[baneyue]

thanks a lot ,

[baneyue]

We have found the cause of this problem because. Wal. SHM and. DB files are out of sync. Our usage scenario will dynamically replace dB. However, the two runtime intermediate files. Wal and. SHM are not replaced synchronously.