1.先存入mysql
 

from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain_ollama import ChatOllama
from langchain_core.runnables.history import RunnableWithMessageHistory # 给普通
的链（chain）添加消息历史管理能力
from langchain_community.chat_message_histories import SQLChatMessageHistory,
RedisChatMessageHistory
llm = ChatOllama(model="qwen3:4b")
prompt = ChatPromptTemplate([
("system", "你是一名专业的游泳规划师"),
MessagesPlaceholder(variable_name="history"),
("human", "{input}")
])
chain = prompt | llm
chain_with_history = RunnableWithMessageHistory(
chain,
lambda session_id: SQLChatMessageHistory(session_id,
connection='mysql+pymysql://root:123456@localhost:3306/test_db'),
input_messages_key="input",
history_messages_key="history"
)
res1 = chain_with_history.invoke({"input": "上海那里好玩"},
config={'configurable': {"session_id": "u532"}})
print(res1)
print("\n\n" + "*" * 100)
res2 = chain_with_history.invoke({"input": "我刚问的问题中最推荐那一个地点"},
config={'configurable': {"session_id": "u532"}})
print(res2)