Langchain+chain+数据库操作

作者：CSDN博客
chain或agents实现。Agents可以多次循环查询。
思路：用户问题—转换—SQL查询——执行SQL——回答问题。

初始化

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1. import os
2. from operator import itemgetter
4. import bs4
5. from langchain.chains.combine_documents import create_stuff_documents_chain
6. from langchain.chains.history_aware_retriever import create_history_aware_retriever
7. from langchain.chains.retrieval import create_retrieval_chain
8. from langchain.chains.sql_database.query import create_sql_query_chain
9. from langchain_chroma import Chroma
10. from langchain_community.document_loaders import WebBaseLoader
11. from langchain_community.tools import QuerySQLDataBaseTool
12. from langchain_community.utilities import SQLDatabase
13. from langchain_core.output_parsers import StrOutputParser
14. from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder, PromptTemplate
15. from langchain_core.runnables import RunnableWithMessageHistory, RunnablePassthrough
16. from langchain_text_splitters import RecursiveCharacterTextSplitter
17. from langchain_community.chat_message_histories import ChatMessageHistory
18. from langchain_openai import ChatOpenAI, OpenAIEmbeddings
20. os.environ['http_proxy'] = '127.0.0.1:7890'
21. os.environ['https_proxy'] = '127.0.0.1:7890'
23. os.environ["LANGCHAIN_TRACING_V2"] = "true"
24. os.environ["LANGCHAIN_PROJECT"] = "LangchainDemo"
25. os.envi

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原文地址：https://blog.csdn.net/qq_52241167/article/details/147332838