(更新:如何在sqflite中存储List< String>数据类型)sqflite错误:DatabaseException(java.lang.String无法转换为java.lang.Integer) [英] (UPDATE: How to store List<String> data type in sqflite) sqflite error: DatabaseException(java.lang.String cannot be cast to java.lang.Integer)
问题描述
我有一个sqflite数据库，其中的表设置了所有列，而唯一键设置为BLOB数据类型.目的是将其存储为二进制数据.我对飞镖和扑打非常陌生，所以我将事情变得尽可能简单.我有int，double，String，List<String>，Map<String:String>和DateTime数据进入这些列.我使用的是.insert()函数，而不是.rawInsert()函数.
I have a sqflite database with a table set up with all columns aside form the unique key set to BLOB data type. The intent is to store as binary data. I'm very new to dart and flutter, so I'm keeping things as simple as possible. I have int, double, String, List<String>, Map<String:String>, and DateTime data going into these columns. I am using the .insert() function, not the .rawInsert() function.
在我的 TEST应用程序中，无论是字符串还是int都不会出现在表中BLOB数据类型.我使用完全相同的代码插入，只是具有不同列的不同对象.在要用于生产的应用程序中，它具有更大，更长的字符串(如base 64中的图像)和更大的整数，我得到了错误.
In my TEST application there is no problem whatsoever with either string or int going into the table as BLOB data type. I'm using exactly the same code to insert, just different objects with different columns. In the application I'm building for production, which has much larger, longer strings (like images in base 64), and much larger integers, I'm getting the error.
奇怪的是，我有类型检查代码，将从我从服务器获取的所有整数数据都转换为实际的整数数据……除了整数以外，没有其他方法可以使用整数.每个值都通过一个只能抛出或返回整数的函数.
The strange thing is, I have type checking code that is converting all of the integer data I'm getting from my server in to actual integer data...there's no possible way that the integers could be anything but integers. Every value goes through a function that can only throw, or return an integer.
然后数据库将如何获取要转换为整数的字符串?
How then would the database be getting a string that it is trying to convert into an integer?
我并不是要寻求解决方案，而是要采取其他故障排除步骤，以至于由于大脑疲劳或缺乏经验而可能会失踪.我遇到了各种各样的障碍.
I'm not asking for a solution, so much as additional troubleshooting steps I should take that I might be missing due to brain fatigue or inexperience. I've hit a roadblock of sorts.
这是引发异常的堆栈跟踪:
Here is the stack trace for the exception being raised:
I/flutter ( 6502): #0 wrapDatabaseException (package:sqflite/src/exception_impl.dart:11:7)
I/flutter ( 6502): <asynchronous suspension>
I/flutter ( 6502): #1 SqfliteDatabaseFactoryImpl.wrapDatabaseException (package:sqflite/src/factory_impl.dart:29:7)
I/flutter ( 6502): #2 _SqfliteDatabaseBase&Object&SqfliteDatabaseMixin.safeInvokeMethod (package:sqflite/src/database_mixin.dart:183:15)
I/flutter ( 6502): #3 _SqfliteDatabaseBase&Object&SqfliteDatabaseMixin.txnRawInsert.<anonymous closure> (package:sqflite/src/database_mixin.dart:340:14)
I/flutter ( 6502): #4 _SqfliteDatabaseBase&Object&SqfliteDatabaseMixin.txnSynchronized.<anonymous closure> (package:sqflite/src/database_mixin.dart:290:22)
I/flutter ( 6502): #5 BasicLock.synchronized (package:synchronized/src/basic_lock.dart:31:26)
I/flutter ( 6502): <asynchronous suspension>
I/flutter ( 6502): #6 _SqfliteDatabaseBase&Object&SqfliteDatabaseMixin.txnSynchronized (package:sqflite/src/database_mixin.dart:286:43)
I/flutter ( 6502): <asynchronous suspension>
I/flutter ( 6502): #7 _SqfliteDatabaseBase&Object&SqfliteDatabaseMixin.txnWriteSynchronized (package:sqflite/src/database_mixin.dart:307:7)
I/flutter ( 6502): #8 _SqfliteDatabaseBase&Object&SqfliteDatabaseMixin.txnRawInsert (package:sqflite/src/database_mixin.dart:339:12)
I/flutter ( 6502): #9 _SqfliteDatabaseBase&Object&SqfliteDatabaseMixin&SqfliteDatabaseExecutorMixin.rawInsert (package:sqflite/src/database_mixin.dart:44:15)
I/flutter ( 6502): #10 _SqfliteDatabaseBase&Object&SqfliteDatabaseMixin&SqfliteDatabaseExecutorMixin.insert (package:sqflite/src/database_mixin.dart:54:12)
I/flutter ( 6502): #11 AppPersistenceManager.insertIntoDatabase (package:gogreen_utility_belt/app/AppPersistenceManager.dart:120:37)
I/flutter ( 6502): <asynchronous suspension>
I/flutter ( 6502): #12 AppNetwork._triggerProductFetchAndCacheWith.<anonymous closure> (package:gogreen_utility_belt/app/AppNetwork.dart:167:38)
I/flutter ( 6502): #13 _rootRunUnary (dart:async/zone.dart:1132:38)
I/flutter ( 6502): #14 _CustomZone.runUnary (dart:async/zone.dart:1029:19)
I/flutter ( 6502): #15 _FutureListener.handleValue (dart:async/future_impl.dart:126:18)
I/flutter ( 6502): #16 Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:639:45)
I/flutter ( 6502): #17 Future._propagateToListeners (dart:async/future_impl.dart:668:32)
I/flutter ( 6502): #18 Future._chainCoreFuture (dart:async/future_impl.dart:454:7)
I/flutter ( 6502): #19 Future._complete (dart:async/future_impl.dart:466:9)
I/flutter ( 6502): #20 _SyncCompleter.complete (dart:async/future_impl.dart:51:12)
I/flutter ( 6502): #21 _AsyncAwaitCompleter.complete (dart:async-patch/async_patch.dart:28:18)
I/flutter ( 6502): #22 _completeOnAsyncReturn (dart:async-patch/async_patch.dart:294:13)
I/flutter ( 6502): #23 compute (package:flutter/src/foundation/_isolates_io.dart)
I/flutter ( 6502): <asynchronous suspension>
I/flutter ( 6502): #24 AppNetwork._triggerProductFetchAndCacheWith (package:gogreen_utility_belt/app/AppNetwork.dart:153:55)
I/flutter ( 6502): <asynchronous suspension>
I/flutter ( 6502): #25 AppNetwork.fetchAndCacheAllProducts (package:gogreen_utility_belt/app/AppNetwork.dart:195:9)
I/flutter ( 6502): #26 _asyncThenWrapperHelper.<anonymous closure> (dart:async-patch/async_patch.dart:77:64)
I/flutter ( 6502): #27 _rootRunUnary (dart:async/zone.dart:1132:38)
I/flutter ( 6502): #28 _CustomZone.runUnary (dart:async/zone.dart:1029:19)
I/flutter ( 6502): #29 _FutureListener.handleValue (dart:async/future_impl.dart:126:18)
I/flutter ( 6502): #30 Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:639:45)
I/flutter ( 6502): #31 Future._propagateToListeners (dart:async/future_impl.dart:668:32)
I/flutter ( 6502): #32 Future._complete (dart:async/future_impl.dart:473:7)
I/flutter ( 6502): #33 _cancelAndValue (dart:async/stream_pipe.dart:63:12)
I/flutter ( 6502): #34 Stream.first.<anonymous closure> (dart:async/stream.dart:1190:11)
I/flutter ( 6502): #35 _rootRunUnary (dart:async/zone.dart:1132:38)
I/flutter ( 6502): #36 _CustomZone.runUnary (dart:async/zone.dart:1029:19)
I/flutter ( 6502): #37 _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)
I/flutter ( 6502): #38 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:336:11)
I/flutter ( 6502): #39 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:263:7)
I/flutter ( 6502): #40 _SyncBroadcastStreamController._sendData (dart:async/broadcast_stream_controller.dart:375:20)
I/flutter ( 6502): #41 _BroadcastStreamController.add (dart:async/broadcast_stream_controller.dart:250:5)
I/flutter ( 6502): #42 _AsBroadcastStreamController.add (dart:async/broadcast_stream_controller.dart:474:11)
I/flutter ( 6502): #43 _rootRunUnary (dart:async/zone.dart:1136:13)
I/flutter ( 6502): #44 _CustomZone.runUnary (dart:async/zone.dart:1029:19)
I/flutter ( 6502): #45 _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)
I/flutter ( 6502): #46 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:336:11)
I/flutter ( 6502): #47 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:263:7)
I/flutter ( 6502): #48 _SyncStreamController._sendData (dart:async/stream_controller.dart:764:19)
I/flutter ( 6502): #49 _StreamController._add (dart:async/stream_controller.dart:640:7)
I/flutter ( 6502): #50 _StreamController.add (dart:async/stream_controller.dart:586:5)
I/flutter ( 6502): #51 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:172:12)
以下是其中涉及的一些功能:
Here is what some of the functions involved look like:
initDatabase() async {
print(new Trace.from(StackTrace.current).terse.frames[0]);
Directory documentsDirectory;
print(
'documentsDirectory set to null, about to assign with an await method');
documentsDirectory = await getApplicationDocumentsDirectory();
print('passed doc dir');
String path = join(documentsDirectory.path, "TestDB.db");
print('passed join');
print(Trace.from(StackTrace.current).terse);
return await openDatabase(path, version: 1, onOpen: (db) {
print('in onOpen');
}, onCreate: (Database database, int version) async {
print('in onCreate async');
for (DatabaseTable databaseTable in DatabaseTable.values) {
print(
'reached inside of "for (DatabaseTable databaseTable in DatabaseTable.values)"');
String executionString =
"CREATE TABLE IF NOT EXISTS ${RawValue.databaseTable(databaseTable)}("
"$uniqueRowKey INTEGER PRIMARY KEY,";
JSONSerializable objectExample;
switch (databaseTable) {
case DatabaseTable.Product:
objectExample = Product.example;
}
print('getting parameters');
List<String> parameters = [];
for (String key
in getDatabaseKeyedMapFrom(serialObject: objectExample).keys) {
parameters.add(key);
}
print('getting unique keys');
List<String> uniqueKeys = [];
var rawUniqueProperties = objectExample.uniqueProperties();
for (String property in rawUniqueProperties) {
uniqueKeys.add(getDatabaseKeyFrom(jsonKey: property));
}
print('iterating through parameters');
for (String parameter in parameters) {
if (parameter != parameters.first) {
executionString += ',';
}
if (uniqueKeys.contains(parameter)) {
uniqueKeys.remove(parameter);
executionString += "$parameter BLOB UNIQUE";
continue;
}
executionString += "$parameter BLOB";
}
executionString += ')';
print('executing string on database');
await database.execute(executionString);
}
});
}
/// Attempts to insert the object into its corresponding table.
Future<DatabaseLocation> insertIntoDatabase(JSONSerializable object) async {
print(new Trace.from(StackTrace.current).terse.frames[0]);
final localDatabase = await database;
String tableName = RawValue.databaseTable(getTableFor(object));
try {
Map<String, dynamic> dbKeyedMap =
getDatabaseKeyedMapFrom(serialObject: object);
int row = await localDatabase.insert(tableName, dbKeyedMap,
conflictAlgorithm: ConflictAlgorithm.replace);
return DatabaseLocation(table: tableName, row: row);
} catch (error, trace) {
printWrapped(error.toString());
printWrapped(trace.toString());
rethrow;
}
}
///converts the String keys of any map representing an object into snake_case
Map<String, dynamic> getDatabaseKeyedMapFrom(
{JSONSerializable serialObject}) {
print(new Trace.from(StackTrace.current).terse.frames[0]);
Map<String, dynamic> jsonKeyedMap = serialObject.toJson();
List<String> jsonPropertyNames = serialObject.propertyNames();
Map<String, dynamic> databaseKeyedMap = {};
for (String jsonPropertyName in jsonPropertyNames) {
ReCase reCase = ReCase(jsonPropertyName);
String databasePropertyName = reCase.snakeCase;
databaseKeyedMap[databasePropertyName] = jsonKeyedMap[jsonPropertyName];
}
return databaseKeyedMap;
}
///converts the String keys of any map representing an object into camelCase
Map<String, dynamic> getJSONKeyedMapFrom(
{Map<String, dynamic> databaseKeyedMap}) {
////print(new Trace.from(StackTrace.current).terse.frames[0]);
List<String> databasePropertyNames = databaseKeyedMap.keys;
Map<String, dynamic> jsonKeyedMap = {};
for (String databasePropertyName in databasePropertyNames) {
ReCase reCase = ReCase(databasePropertyName);
String jsonPropertyName = reCase.camelCase;
jsonKeyedMap[jsonPropertyName] = databaseKeyedMap[databasePropertyName];
}
return jsonKeyedMap;
}
这是数据库中使用的产品模型.
我将生产代码模型中表示的所有数据类型添加到我的测试应用程序模型中，并且能够复制该错误.请参阅顶部的测试应用程序链接.我一步一步地删除了新的数据类型，直到错误消失，然后才能够确定是导致此错误的是List数据类型.我仔细检查了地图，发现它不会造成任何麻烦.
I added all of the data types represented in the production code model to my test app model, and was able to duplicate the error. See the test application link at the top. I removed the new data types one by one until the error went away, and was able to find out that it's the List data type that generates this error. I double checked the Map, that one doesn't cause any trouble.
那么，精致的问题是:如何使用sqflite存储字符串列表?我不想只是将其存储为原始JSON字符串...那会很烂...
So, refined question: how do I store a list of strings using sqflite? I don't want to just store it as the original JSON string...that would suck...
推荐答案
您必须展平模型.请参阅支持的类型帮助部分.
You have to flatten your model. See the supported types help section.
基本上仅支持int，double，String和Uint8List(blob)类型.
不幸的是，您必须转换内部的List<String>和Map<String:String>，其中json是一种解决方案.
Basically int, double, String and Uint8List(blob) are the only types supported.
Unfortunately you have to convert your inner List<String> and Map<String:String>, json being one solution.
这篇关于(更新:如何在sqflite中存储List< String>数据类型)sqflite错误:DatabaseException(java.lang.String无法转换为java.lang.Integer)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
