diff --git a/backend/services/chat/chat.py b/backend/services/chat/chat.py
index 75222ba..d28222e 100644
--- a/backend/services/chat/chat.py
+++ b/backend/services/chat/chat.py
@@ -10,6 +10,7 @@
 from services.knowledgebase.knowledgebase_service import KBase
 from fastapi import HTTPException
 import datetime
+import logging
 from typing import List
 from core.utils.utils import GetDeafultLLM_Chat,GetDefaultEmbedding
 class Chat:
@@ -19,6 +20,9 @@ def __init__(self, conversation_id,user_id,rag:RAG_Pipeline):
         self.mysql_session = MysqlClient().SessionLocal()
         self.rag:RAG_Pipeline  = rag
         self.default_llm_config = GetDeafultLLM_Chat()
+        if self.default_llm_config is None:
+            logging.error("GetDeafultLLM_Chat() returned None. No default LLM configuration found.")
+            raise HTTPException(status_code=500, detail="No default LLM configuration found. Please configure a default LLM.")
         self.default_embedding_config = GetDefaultEmbedding()
     def __del__(self):
         self.mysql_session.close()
@@ -32,7 +36,9 @@ def create_conversation(self,knowledgeBaseId:str,username)->Conversation:
             # print("Conversation created successfully")
             return new_conversation
         except Exception as e:
-            print(e)
+            logging.error(f"Error creating conversation: {e}")
+            self.mysql_session.rollback()
+            raise
     
     
     #匹配对话
@@ -56,9 +62,14 @@ def match_knowledgebase(self, conversation_id,username)->KnowledgeBase:
                 return knowledgebase
             
         except Exception as e:
-            print(f"Erreor:{e}")
+            logging.error(f"Error matching knowledgebase: {e}")
+            raise
     # 生成对话标题
     def generate_conversation_title(self, conversation_id,username:str)->str:
+        if self.default_llm_config is None:
+            logging.error("default_llm_config is None in generate_conversation_title")
+            raise HTTPException(status_code=500, detail="No default LLM configuration available")
+        
         llm = LLM_Manager().creatLLM(mode_provider=self.default_llm_config.vendor_type,model=self.default_llm_config.model)
                 
         conversation_messages = self.load_conversation(conversation_id,username=username)
@@ -76,8 +87,10 @@ def generate_conversation_title(self, conversation_id,username:str)->str:
 #########################
             """
         prompt = f"""
-请根据以下对话内容生成一个对话标题，对话内容如下：\n
-{messageLogs_txt}\n
+请根据以下对话内容生成一个对话标题，对话内容如下：
+
+{messageLogs_txt}
+
 请生成一个简洁明了的对话标题，不超过10个字,且仅需要输出标题,如果没有内容则输出:新对话
 """
             
@@ -100,7 +113,8 @@ def get_knowledgebases(self,username:str):
             all_kbse = self.mysql_session.query(KnowledgeBase).filter((KnowledgeBase.created_by == username) | (KnowledgeBase.is_public == True),KnowledgeBase.delete_sign == False)
             return all_kbse
         except Exception as e:
-            print(f"获取知识库失败:{e}")
+            logging.error(f"Error getting knowledgebases: {e}")
+            raise
     # 更改知识库
     def change_knowledgebase(self, conversation_id,knowledgeBaseId,username):
         try:
@@ -110,7 +124,9 @@ def change_knowledgebase(self, conversation_id,knowledgeBaseId,username):
             self.mysql_session.refresh(conversation)
             return conversation
         except Exception as e:
-            print(e)
+            logging.error(f"Error changing knowledgebase: {e}")
+            self.mysql_session.rollback()
+            raise
     # 删除对话
     def delete_conversation(self, conversation_id,username:str)->Conversation:
         try:
@@ -124,7 +140,9 @@ def delete_conversation(self, conversation_id,username:str)->Conversation:
                 return conversation
             
         except Exception as e:
-            print(e)
+            logging.error(f"Error deleting conversation: {e}")
+            self.mysql_session.rollback()
+            raise
     # 重命名对话
     def rename_conversation(self, conversation_id,username, new_name):
         try:
@@ -139,7 +157,9 @@ def rename_conversation(self, conversation_id,username, new_name):
 
                 return conversation
         except Exception as e:
-            print(e)
+            logging.error(f"Error renaming conversation: {e}")
+            self.mysql_session.rollback()
+            raise
     # 加载对话
     def load_conversation(self, conversation_id,username:str)->List[ChatMessageHistory]:
         # 检查对话是否属于用户
@@ -174,7 +194,8 @@ def load_conversation(self, conversation_id,username:str)->List[ChatMessageHisto
 
             return messages_history
         except Exception as e:
-            print(e)
+            logging.error(f"Error loading conversation: {e}")
+            raise
     
     # 格式化对话记录
     def format_conversation_Log(self, messages:List[Chat_Messages]):
@@ -199,12 +220,18 @@ def save_conversation(self, message:Chat_Messages):
             self.mysql_session.commit()
             self.mysql_session.refresh(message)
         except Exception as e:
-            print(e)
+            logging.error(f"Error saving conversation: {e}")
+            self.mysql_session.rollback()
+            raise
     
     # 回答问题
     def answer_question(self, resultByDoc: ResultByDoc,history_message=[],streaming=False):
         # rAG_Pipeline = RAG_Pipeline()
             
+        if self.default_llm_config is None:
+            logging.error("default_llm_config is None in answer_question")
+            raise HTTPException(status_code=500, detail="No default LLM configuration available")
+        
         answer = self.rag.generate_answer_by_knowledgebase(resultByDoc=resultByDoc,history_messages=history_message,streaming=streaming,LLM_Provider=self.default_llm_config.vendor_type,LLM_Model=self.default_llm_config.model)
         if isinstance(answer, str):
             print(answer)
@@ -226,7 +253,8 @@ def get_retrieve_documents(self, question,knowledgebase_id,rag_model:int,is_rera
             resultByDoc:ResultByDoc =  self.rag.retrieve_documents(question=question,knowledge_base_id=knowledgebase_id,rag_model=rag_model,is_rerank=is_rerank)
             return resultByDoc
         except Exception as e:
-            print(e)
+            logging.error(f"Error retrieving documents: {e}")
+            raise
     # 处理用户输入
     def run(self, chatMessageRequest: ChatMessageRequest,username, streaming=False):
         # 获取用户输入
@@ -262,7 +290,8 @@ def run(self, chatMessageRequest: ChatMessageRequest,username, streaming=False):
                 knowledgeBaseId=knowledgebase.knowledgeBaseId,
                 timeStamp=datetime.datetime.now()
             )
-            self.save_conversation(new_message)
+            self.mysql_session.add(new_message)
+            self.mysql_session.flush()
 
             # 保存检索文档
             for doc in resultByDoc.source:
@@ -273,23 +302,29 @@ def run(self, chatMessageRequest: ChatMessageRequest,username, streaming=False):
                     messageId=new_message.id
                 )
                 self.mysql_session.add(retriever_doc)
-            self.mysql_session.commit()
 
             answer = ""
             # 生成回答
             if streaming:
                 answer_generator  = self.answer_question(resultByDoc=resultByDoc,  history_message=messageLog, streaming=True)
                 if isinstance(answer_generator, str):
-                    pass
-                else:
-                    
-                    for item in answer_generator :
-                        yield item
-                        answer+=item
-                    # 流式输出完成后更新答案到数据库
+                    answer = answer_generator
                     new_message.answer = answer
-                    self.mysql_session.commit()  # 更新数据库
+                    self.mysql_session.commit()
                     self.mysql_session.refresh(new_message)
+                else:
+                    try:
+                        for item in answer_generator :
+                            yield item
+                            answer+=item
+                        # 流式输出完成后更新答案到数据库
+                        new_message.answer = answer
+                        self.mysql_session.commit()  # 更新数据库
+                        self.mysql_session.refresh(new_message)
+                    except Exception as e:
+                        logging.error(f"Error during streaming chat: {e}")
+                        self.mysql_session.rollback()
+                        raise
             else:
                 answer = self.answer_question(resultByDoc=resultByDoc,  history_message=messageLog, streaming=False)
                 if isinstance(answer, str):
@@ -300,17 +335,27 @@ def run(self, chatMessageRequest: ChatMessageRequest,username, streaming=False):
                     
                     return answer
                 else:
-                    for item in answer:
-                        yield item
+                    try:
+                        for item in answer:
+                            yield item
+                            answer+=item
+                        new_message.answer = answer
+                        self.mysql_session.commit()
+                        self.mysql_session.refresh(new_message)
+                    except Exception as e:
+                        logging.error(f"Error during non-streaming chat: {e}")
+                        self.mysql_session.rollback()
+                        raise
 
         except Exception as e:
-            print(f"Error Chat Run: {e}")
+            logging.error(f"Error Chat Run: {e}")
+            self.mysql_session.rollback()
+            raise
 
     
 
 
 
-
 """
 临时梳理逻辑
 
@@ -326,4 +371,4 @@ def run(self, chatMessageRequest: ChatMessageRequest,username, streaming=False):
 
 所以需要有一个创建对话的接口，不能根据判断对话id是否为空来创建对话
 
-"""
\ No newline at end of file
+"""