56 lines
1.6 KiB
Dart
56 lines
1.6 KiB
Dart
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import 'dart:io';
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import 'package:sqflite/sqflite.dart';
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import 'package:path/path.dart';
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import 'package:path_provider/path_provider.dart';
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class DatabaseHelper {
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static final DatabaseHelper _instance = DatabaseHelper._internal();
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factory DatabaseHelper() => _instance;
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static Database? _database;
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DatabaseHelper._internal();
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Future<Database> get database async {
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if (_database != null) return _database!;
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_database = await _initDatabase();
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return _database!;
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}
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Future<Database> _initDatabase() async {
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Directory documentsDirectory = await getApplicationDocumentsDirectory();
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String path = join(documentsDirectory.path, 'chat.db');
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return await openDatabase(
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path,
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version: 1,
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onCreate: _onCreate,
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);
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}
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Future<void> _onCreate(Database db, int version) async {
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await db.execute('''
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CREATE TABLE messages (
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id INTEGER PRIMARY KEY AUTOINCREMENT,
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role TEXT NOT NULL,
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message TEXT NOT NULL,
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timestamp INTEGER DEFAULT (strftime('%s', 'now'))
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''');
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}
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// 插入一条消息
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Future<int> insertMessage(Map<String, dynamic> message) async {
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Database db = await database;
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return await db.insert('messages', message);
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}
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// 获取所有消息（按时间排序）
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Future<List<Map<String, dynamic>>> getMessages() async {
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Database db = await database;
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return await db.query('messages', orderBy: 'timestamp ASC');
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}
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// 删除所有消息
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Future<int> clearMessages() async {
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Database db = await database;
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return await db.delete('messages');
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}
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}
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