Implement follow-up detection in dialog context to prevent context pollution in multi-topic conversations. Introduce is_likely_follow_up function to determine when to inject session history based on user input. Adjust _load_session_text2sql_context to conditionally include context based on follow-up status, enhancing SQL generation accuracy. Update relevant API endpoints to pass user text for improved context handling.

api_server.py

@@ -35,6 +35,7 @@ from utils.dialog_classifier import DialogIntent, classify_dialog
 from utils.dialog_context import (
     last_assistant_was_data_query,
     messages_to_text2sql_context,
+    is_likely_follow_up,
 )
 
 logging.basicConfig(
@@ -246,6 +247,7 @@ def _conversation_nl_dict(reply: str) -> Dict[str, Any]:
 
 async def _load_session_text2sql_context(
     request: NLChatRequest,
+    user_text: str,
 ) -> tuple[str, bool]:
     """
     在写入本轮之前读取会话历史，构造 Text2SQL 上文，并判断上一轮助手是否为数据查询。
@@ -266,7 +268,9 @@ async def _load_session_text2sql_context(
     if not items:
         return "", False
     last_data = last_assistant_was_data_query(items)
-    block, _n = messages_to_text2sql_context(items)
+    # 方案A：仅在“续问/沿用口径”时注入少量上文；新话题直接清空，避免上下文污染 SQL。
+    max_pairs = 2 if is_likely_follow_up(user_text) else 0
+    block, _n = messages_to_text2sql_context(items, max_pairs=max_pairs)
     return block, last_data
 
 
@@ -377,7 +381,7 @@ async def _chat_stream_events(request: NLChatRequest) -> AsyncIterator[bytes]:
         return
     text = request.message.strip()
     orch = get_orchestrator()
-    dialog_block, last_data = await _load_session_text2sql_context(request)
+    dialog_block, last_data = await _load_session_text2sql_context(request, text)
     classified = await asyncio.to_thread(
         classify_dialog,
         text,
@@ -461,7 +465,7 @@ async def nl_chat(request: NLChatRequest):
         text = request.message.strip()
         logger.info(f"[API] 问题: {text[:100]}...")
         orch = get_orchestrator()
-        dialog_block, last_data = await _load_session_text2sql_context(request)
+        dialog_block, last_data = await _load_session_text2sql_context(request, text)
         classified = await asyncio.to_thread(
             classify_dialog,
             text,