基础功能

lib/utils/note_dao.dart

@@ -0,0 +1,69 @@
+import 'package:sqflite/sqflite.dart';
+import '../models/data_models.dart';
+import 'database_helper.dart';
+
+/// 笔记数据访问对象
+class NoteDao {
+  final DatabaseHelper _dbHelper = DatabaseHelper.instance;
+
+  // 获取所有笔记
+  Future<List<Note>> getAllNotes() async {
+    final db = await _dbHelper.database;
+    final List<Map<String, dynamic>> maps = await db.query(
+      'notes',
+      orderBy: 'updated_at DESC',
+    );
+
+    return List.generate(maps.length, (i) {
+      return Note(
+        id: maps[i]['id'].toString(),
+        title: maps[i]['title'],
+        content: maps[i]['content'],
+        tags: maps[i]['tags'] != null 
+            ? List<String>.from(maps[i]['tags'].split(',')) 
+            : [],
+        createdAt: DateTime.parse(maps[i]['created_at']),
+        updatedAt: DateTime.parse(maps[i]['updated_at']),
+      );
+    });
+  }
+
+  // 添加笔记
+  Future<int> insertNote(Note note) async {
+    final db = await _dbHelper.database;
+    return await db.insert('notes', {
+      'id': note.id,
+      'title': note.title,
+      'content': note.content,
+      'tags': note.tags.join(','),
+      'created_at': note.createdAt.toIso8601String(),
+      'updated_at': note.updatedAt.toIso8601String(),
+    });
+  }
+
+  // 更新笔记
+  Future<int> updateNote(Note note) async {
+    final db = await _dbHelper.database;
+    return await db.update(
+      'notes',
+      {
+        'title': note.title,
+        'content': note.content,
+        'tags': note.tags.join(','),
+        'updated_at': note.updatedAt.toIso8601String(),
+      },
+      where: 'id = ?',
+      whereArgs: [note.id],
+    );
+  }
+
+  // 删除笔记
+  Future<int> deleteNote(String id) async {
+    final db = await _dbHelper.database;
+    return await db.delete(
+      'notes',
+      where: 'id = ?',
+      whereArgs: [id],
+    );
+  }
+}