删掉杂项

backend/database.py

@@ -1,22 +1,32 @@
-from sqlalchemy import create_engine, MetaData, Table
+from sqlalchemy import create_engine, MetaData, Table, event
+from pgvector.sqlalchemy import Vector  # 必须导入这个
 from .config import settings
 
 class Database:
     def __init__(self):
+        # 1. 创建引擎
         self.engine = create_engine(settings.DATABASE_URL, pool_pre_ping=True)
+        
+        # 2. 【核心修复】手动注册 vector 类型，让反射能识别它
+        # 这告诉 SQLAlchemy：如果在数据库里看到名为 "vector" 的类型，请使用 pgvector 库的 Vector 类来处理
+        self.engine.dialect.ischema_names['vector'] = Vector
+        
         self.metadata = MetaData()
         self.tasks = None
         self.queue = None
         self.chunks = None
+        
         self._reflect_tables()
 
     def _reflect_tables(self):
         try:
             # 自动从数据库加载表结构
+            # 因为上面注册了 ischema_names，现在 chunks_table.c.embedding 就能被正确识别为 Vector 类型了
             self.tasks = Table('crawl_tasks', self.metadata, autoload_with=self.engine)
             self.queue = Table('crawl_queue', self.metadata, autoload_with=self.engine)
             self.chunks = Table('knowledge_chunks', self.metadata, autoload_with=self.engine)
         except Exception as e:
             print(f"❌ 数据库表加载失败: {e}")
 
+# 全局单例
 db_instance = Database()