改用mysql

backend/app/core/config.py

@@ -1,8 +1,8 @@
 """全局配置：pydantic-settings，全部来自环境变量 / .env。
 
-规则（docs/technical-review.md §1.3）：
+规则：
 - 密钥不得硬编码；SECRET_KEY 缺失或仍为模板值时，生产环境拒绝启动。
-- DATABASE_URL 可切换 PostgreSQL（扩展接口 1）。
+- DATABASE_URL 支持 MySQL / SQLite。
 """
 
 from functools import lru_cache
@@ -22,7 +22,7 @@ class Settings(BaseSettings):
     secret_key: str = Field(min_length=16)
 
     # --- 数据库 ---
-    database_url: str = "sqlite:///./data/app.db"
+    database_url: str = "mysql+pymysql://admin:Lzcc6-01@47.109.98.44:33306/amb_rag?charset=utf8mb4"
 
     # --- 文件存储 ---
     storage_root: str = "./data"
@@ -42,6 +42,14 @@ class Settings(BaseSettings):
     def is_production(self) -> bool:
         return self.environment == "production"
 
+    @property
+    def is_mysql(self) -> bool:
+        return "mysql" in self.database_url
+
+    @property
+    def is_sqlite(self) -> bool:
+        return "sqlite" in self.database_url
+
     @property
     def storage_root_path(self) -> Path:
         return Path(self.storage_root).resolve()
@@ -63,4 +71,4 @@ class Settings(BaseSettings):
 def get_settings() -> Settings:
     s = Settings()  # type: ignore[call-arg]
     s.validate_secrets()
-    return s
+    return s

backend/app/core/db.py

@@ -1,18 +1,17 @@
-"""SQLAlchemy 2.x 同步引擎 + 会话管理（MVP: SQLite）。
+"""SQLAlchemy 2.x 同步引擎 + 会话管理。
 
-切换 PostgreSQL 时（扩展接口 1）：
-1. DATABASE_URL 改为 postgresql+asyncpg://...
-2. 引擎换 create_async_engine + async_sessionmaker
-3. get_session 改 async generator + yield
-4. 业务层 Repository 调用加 await
+支持 MySQL / SQLite，通过 DATABASE_URL 自动切换。
 """
 
 from collections.abc import Generator
 
-from sqlalchemy import create_engine
+from sqlalchemy import create_engine, event, text
 from sqlalchemy.orm import Session, sessionmaker
 
 from app.core.config import get_settings
+from app.core.logging import get_logger
+
+logger = get_logger(__name__)
 
 _engine = None
 _session_factory: sessionmaker[Session] | None = None
@@ -22,24 +21,48 @@ def get_engine():
     global _engine
     if _engine is None:
         settings = get_settings()
-        _engine = create_engine(
-            settings.database_url,
-            pool_pre_ping=True,
-            echo=False,
-            # SQLite 专属：启用 WAL 模式（并发读 + 写串行化）
-            connect_args={"check_same_thread": False} if "sqlite" in settings.database_url else {},
-        )
-        # SQLite: 启用 WAL 模式与外键约束
-        if "sqlite" in settings.database_url:
-            from sqlalchemy import event, text
 
+        engine_kwargs = {
+            "pool_pre_ping": True,
+            "echo": False,
+        }
+
+        if settings.is_mysql:
+            # MySQL 配置
+            engine_kwargs.update({
+                "pool_size": 10,
+                "max_overflow": 20,
+                "pool_recycle": 3600,  # 1 小时回收连接，防止 MySQL 超时断开
+                "connect_args": {
+                    "charset": "utf8mb4",
+                },
+            })
+        elif settings.is_sqlite:
+            # SQLite 配置
+            engine_kwargs["connect_args"] = {"check_same_thread": False}
+
+        _engine = create_engine(settings.database_url, **engine_kwargs)
+
+        # SQLite: 启用 WAL 模式 + 外键约束
+        if settings.is_sqlite:
             @event.listens_for(_engine, "connect")
-            def _set_sqlite_pragma(dbapi_conn, _):  # type: ignore[no-untyped-def]
+            def _set_sqlite_pragma(dbapi_conn, _):
                 cursor = dbapi_conn.cursor()
                 cursor.execute("PRAGMA journal_mode=WAL")
                 cursor.execute("PRAGMA foreign_keys=ON")
                 cursor.close()
 
+        # MySQL: 设置字符集和 SQL 模式
+        if settings.is_mysql:
+            @event.listens_for(_engine, "connect")
+            def _set_mysql_session(dbapi_conn, _):
+                cursor = dbapi_conn.cursor()
+                cursor.execute("SET NAMES utf8mb4")
+                cursor.execute("SET SESSION sql_mode='STRICT_TRANS_TABLES,NO_ZERO_DATE,NO_ZERO_IN_DATE,ERROR_FOR_DIVISION_BY_ZERO'")
+                cursor.close()
+
+        logger.info("Database engine created: %s", "MySQL" if settings.is_mysql else "SQLite")
+
     return _engine
 
 
@@ -73,4 +96,4 @@ def dispose_engine() -> None:
     if _engine is not None:
         _engine.dispose()
     _engine = None
-    _session_factory = None
+    _session_factory = None