feat(db): 初始化数据库并创建 APIProvider 表

- 新增 init_db.py 文件，实现数据库初始化和 APIProvider 表的创建
- 新增 dataset_generation.py 文件，定义 LLMRequest、LLMResponse 和 APIProvider 模型
- 在初始化数据库时，如果环境变量中存在 API_KEY、BASE_URL 和 MODEL_ID，会自动添加一条 APIProvider 记录

db/init_db.py

@@ -0,0 +1,52 @@
+from sqlmodel import SQLModel, create_engine, Session
+from sqlmodel import select
+from typing import Optional
+import os
+from pathlib import Path
+import sys
+from dotenv import load_dotenv
+from sqlalchemy.engine import Engine
+
+# 项目路径配置
+sys.path.append(str(Path(__file__).resolve().parent.parent))
+from schema.dataset_generation import APIProvider
+
+# 全局引擎实例（可选）
+_engine: Optional[Engine] = None
+
+def get_engine(workdir: str) -> Engine:
+    global _engine
+    if not _engine:
+        db_dir = os.path.join(workdir, "db")
+        os.makedirs(db_dir, exist_ok=True)
+        db_path = os.path.join(db_dir, "db.sqlite")
+        db_url = f"sqlite:///{db_path}"
+        _engine = create_engine(db_url)
+    return _engine
+
+def initialize_db(engine: Engine) -> None:
+    SQLModel.metadata.create_all(engine)
+    load_dotenv()
+    api_key = os.getenv("API_KEY")
+    base_url = os.getenv("BASE_URL")
+    model_id = os.getenv("MODEL_ID")
+    
+    if api_key and base_url and model_id:
+        with Session(engine) as session:
+            # 使用新的 select() 语法查询
+            statement = select(APIProvider).limit(1)
+            existing_provider = session.exec(statement).first()
+            
+            if not existing_provider:
+                provider = APIProvider(
+                    base_url=base_url,
+                    model_id=model_id,
+                    api_key=api_key
+                )
+                session.add(provider)
+                session.commit()
+
+if __name__ == "__main__":
+    workdir = os.path.join(os.path.dirname(__file__), "..", "workdir")
+    engine = get_engine(workdir)
+    initialize_db(engine)

schema/dataset_generation.py

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+from datetime import datetime, timezone
+from typing import Optional
+from sqlmodel import SQLModel, Relationship, Field
+
+class APIProvider(SQLModel, table=True):
+    id: Optional[int] = Field(default=None, primary_key=True)
+    base_url: str = Field(..., description="API的基础URL")
+    model_id: str = Field(..., description="API使用的模型ID")
+    api_key: Optional[str] = Field(default=None, description="用于身份验证的API密钥")
+    created_at: datetime = Field(
+        default_factory=lambda: datetime.now(timezone.utc),
+        description="记录创建时间"
+    )
+
+class LLMResponse(SQLModel):
+    timestamp: datetime  = Field(
+        default_factory=lambda: datetime.now(timezone.utc),
+        description="响应的时间戳"
+    )
+    response_id: str = Field(..., description="响应的唯一ID")
+    tokens_usage: dict = Field(default_factory=lambda: {
+        "prompt_tokens": 0,
+        "completion_tokens": 0,
+        "prompt_cache_hit_tokens": None,
+        "prompt_cache_miss_tokens": None
+    }, description="token使用信息")
+    response_content: dict = Field(default_factory=dict, description="API响应的内容")
+    total_duration: float = Field(default=0.0, description="请求的总时长，单位为秒")
+    llm_parameters: dict = Field(default_factory=lambda: {
+        "temperature": None,
+        "max_tokens": None,
+        "top_p": None,
+        "frequency_penalty": None,
+        "presence_penalty": None,
+        "seed": None
+    }, description="API的生成参数")
+
+class LLMRequest(SQLModel):
+    prompt: str = Field(..., description="发送给API的提示词") 
+    provider_id: int = Field(foreign_key="apiprovider.id")
+    provider: APIProvider = Relationship()
+    format: Optional[str] = Field(default=None, description="API响应的格式")
+    response: list[LLMResponse] = Field(default_factory=list, description="API响应列表")
+    error: Optional[list[str]] = Field(default=None, description="API请求过程中发生的错误信息")
+    total_duration: float = Field(default=0.0, description="请求的总时长，单位为秒")
+    total_tokens_usage: dict = Field(default_factory=lambda: {
+        "prompt_tokens": 0,
+        "completion_tokens": 0,
+        "prompt_cache_hit_tokens": None,
+        "prompt_cache_miss_tokens": None
+    }, description="token使用信息")