Update app.py

app.py

@@ -9,7 +9,7 @@ from langchain.agents import create_sql_agent
 from langchain import OpenAI
 from langchain import PromptTemplate, OpenAI, LLMChain
 from langchain.chains import SimpleSequentialChain
-from langchain import SQLDatabaseChain
+from langchain_experimental.sql import SQLDatabaseChain
 from langchain.agents.agent_toolkits import create_python_agent
 from langchain.tools.python.tool import PythonREPLTool
 from langchain.python import PythonREPL