优化数据库模型与关系

models/source_link.py

@@ -1,7 +1,7 @@
 # my_project/models/source_link.py
 
 from typing import TYPE_CHECKING, Optional
-from sqlmodel import Field, Relationship, Column, func, DateTime
+from sqlmodel import Field, Relationship, Index
 from .base import TableBase
 from datetime import datetime
 
@@ -10,6 +10,9 @@ if TYPE_CHECKING:
 
 class SourceLink(TableBase, table=True):
     __tablename__ = 'source_links'
+    __table_args__ = (
+        Index("ix_sourcelink_file_name", "file_id", "name"),
+    )
 
     name: str = Field(max_length=255, description="链接名称")
     downloads: int = Field(default=0, sa_column_kwargs={"server_default": "0"}, description="通过此链接的下载次数")