抛出参数错误( "nullColumnHack required when inserting no data" );颤振中的异常

Question

我正在处理SqFlite程序，但它显示ArgumentError异常。我的代码不起作用，这表明我无法将数据插入数据库。请有人帮我做这个。未执行类似CRUD的SQFlite操作。

异常，如ArgumentError异常，如出现某些带有异常显示的默认dart文件。异常抛出ArgumentError("不插入数据时需要nullColumnHack"(；

import 'dart:async';
import 'dart:io';
import 'package:sqflite/sqflite.dart';
import 'package:path_provider/path_provider.dart';
import 'package:sqlite_app/models/note.dart';

class DatabaseHelper {
static DatabaseHelper _databaseHelper;
static Database _database;
String noteTable = 'note_table';
String colId = 'id';
String colTitle = 'title';
String colDescription = 'description';
String colPriority = 'priority';
String colDate = 'date';

DatabaseHelper._createInstance();
factory DatabaseHelper(){
if (_databaseHelper == null) {
_databaseHelper = DatabaseHelper._createInstance();
}
return _databaseHelper;
}

Future<Database> get databse async {
if (_database == null) {
_database = await initalizeDatabase();
}
return _database;
}
Future<Database> initalizeDatabase() async {
Directory directory = await getApplicationDocumentsDirectory();
String path = directory.path + 'note.db';
var noteDatabase = await openDatabase(
path, version: 1, onCreate: _createDb);
return noteDatabase;
}
void _createDb(Database db, int newVersion) async {
await db.execute(
'CREATE TABLE $noteTable ($colId INTEGER PRIMARY KEY AUTOINCREMENT,$colTitle TEXT,'
'$colDescription TEXT,$colPriority INTEGER,$colDate TEXT)');
}

Future<List<Map<String, dynamic>>> getNoteMapList() async {
Database db = await this.databse;
//var result=await db.rawQuery('SELECT * FROM $noteTable order by $colPriority ASC');
var result = await db.query(noteTable, orderBy: '$colPriority ASC');
return result;
}

Future<int> insertNote(Note note) async {
Database db = await this.databse;
var result = await db.insert(noteTable, note.toMap());
return result;
}

Future<int> updateNote(Note note) async {
var db = await this.databse;
var result = await db.update(
noteTable, note.toMap(), where: '$colId=?', whereArgs: [note.id]);
return result;
}
Future<int> deleteNote(int id) async {
var db = await this.databse;
int result = await db.rawDelete('DELETE FROM $noteTable WHERE $colId=$id');
return result;
}

Future<int> getCount() async {
Database db = await this.databse;
List<Map<String, dynamic>> x = await db.rawQuery(
"SELECT COUNT (*) from $noteTable");
int result = Sqflite.firstIntValue(x);
return result;
}

Future<List<Note>> getNoteList() async {
var noteMapList = await getNoteMapList();
int count = noteMapList.length;
List<Note> noteList = List<Note>();
for (int i = 0; i < count; i++) {
noteList.add(Note.fromMapObject(noteMapList[i]));
}
return noteList;
}
}

Answer 1

只需在db.insert(即nullColumnHack(中再传递一个参数，其值等于自动递增ID Integer。。。它会起作用。。。对所有其他操作执行此操作。。。

Future<int> insertNote(Note note) async {
Database db = await this.databse;
var result = await db.insert(noteTable, note.toMap(),nullColumnHack: colId);
return result;
}