error در sqlite

سلام استاد من سعی کردم دیتابیس رو اجرا کنم ولی نشد این خطا رو برام آورد در ضمن آیدی رو خطا میداد که به صورت لیزی تعریف کردم Error: Unexpected null value. at Object.throw_ [as throw] (http://localhost:43403/dart_sdk.js:5041:11) at Object.nullCheck (http://localhost:43403/dart_sdk.js:5366:30) at platform_channel.MethodChannel.new.get binaryMessenger [as binaryMessenger] (http://localhost:43403/packages/flutter/src/services/system_channels.dart.l ib.js:931:32) at platform_channel.MethodChannel.new._invokeMethod (http://localhost:43403/packages/flutter/src/services/system_channels.dart.l ib.js:938:34) at _invokeMethod.next () at runBody (http://localhost:43403/dart_sdk.js:37422:34) at Object._async [as async] (http://localhost:43403/dart_sdk.js:37453:7) at platform_channel.MethodChannel.new.[_invokeMethod] (http://localhost:43403/packages/flutter/src/services/system_channels.dart.l ib.js:936:20) at platform_channel.MethodChannel.new.invokeMethod (http://localhost:43403/packages/flutter/src/services/system_channels.dart.l ib.js:949:33) at method_channel_path_provider.MethodChannelPathProvider.new.getApplicationDoc umentsPath (http://localhost:43403/packages/path_provider_platform_interface/src/method _channel_path_provider.dart.lib.js:122:33) at getApplicationDocumentsDirectory (http://localhost:43403/packages/path_provider/path_provider.dart.lib.js:91: 49) at getApplicationDocumentsDirectory.next () at runBody (http://localhost:43403/dart_sdk.js:37422:34) at Object._async [as async] (http://localhost:43403/dart_sdk.js:37453:7) at Object.getApplicationDocumentsDirectory (http://localhost:43403/packages/path_provider/path_provider.dart.lib.js:90: 18) at myDb.MyDB.local.initDb (http://localhost:43403/packages/mysqlite2/myDb.dart.lib.js:67:55) at initDb.next () at runBody (http://localhost:43403/dart_sdk.js:37422:34) at Object._async [as async] (http://localhost:43403/dart_sdk.js:37453:7) at myDb.MyDB.local.initDb (http://localhost:43403/packages/mysqlite2/myDb.dart.lib.js:66:20) at myDb.MyDB.local.database (http://localhost:43403/packages/mysqlite2/myDb.dart.lib.js:61:55) at database.next () at runBody (http://localhost:43403/dart_sdk.js:37422:34) at Object._async [as async] (http://localhost:43403/dart_sdk.js:37453:7) at myDb.MyDB.local.get database [as database] (http://localhost:43403/packages/mysqlite2/myDb.dart.lib.js:57:20) at myDb.MyDB.local.insert (http://localhost:43403/packages/mysqlite2/myDb.dart.lib.js:81:30) at insert.next () at runBody (http://localhost:43403/dart_sdk.js:37422:34) at Object._async [as async] (http://localhost:43403/dart_sdk.js:37453:7) at myDb.MyDB.local.insert (http://localhost:43403/packages/mysqlite2/myDb.dart.lib.js:80:20) at main (http://localhost:43403/packages/mysqlite2/main.dart.lib.js:147:25) at main.next () at runBody (http://localhost:43403/dart_sdk.js:37422:34) at Object._async [as async] (http://localhost:43403/dart_sdk.js:37453:7) at main$ (http://localhost:43403/packages/mysqlite2/main.dart.lib.js:145:18) at main (http://localhost:43403/web_entrypoint.dart.lib.js:33:29) at main.next () at http://localhost:43403/dart_sdk.js:37403:33 at _RootZone.runUnary (http://localhost:43403/dart_sdk.js:37274:59) at _FutureListener.thenAwait.handleValue (http://localhost:43403/dart_sdk.js:32530:29) at handleValueCallback (http://localhost:43403/dart_sdk.js:33057:49) at Function._propagateToListeners (http://localhost:43403/dart_sdk.js:33095:17) at _Future.new.[_completeWithValue] (http://localhost:43403/dart_sdk.js:32943:23) at http://localhost:43403/dart_sdk.js:32194:46 at _RootZone.runUnary (http://localhost:43403/dart_sdk.js:37274:59) at _FutureListener.then.handleValue (http://localhost:43403/dart_sdk.js:32530:29) at handleValueCallback (http://localhost:43403/dart_sdk.js:33057:49) at Function._propagateToListeners (http://localhost:43403/dart_sdk.js:33095:17) at _Future.new.[_completeWithValue] (http://localhost:43403/dart_sdk.js:32943:23) at async._AsyncCallbackEntry.new.callback (http://localhost:43403/dart_sdk.js:32964:35) at Object._microtaskLoop (http://localhost:43403/dart_sdk.js:37526:13) at _startMicrotaskLoop (http://localhost:43403/dart_sdk.js:37532:13) at http://localhost:43403/dart_sdk.js:33303:9