cancel
Showing results for 
Search instead for 
Did you mean: 
Generative AI
Explore discussions on generative artificial intelligence techniques and applications within the Databricks Community. Share ideas, challenges, and breakthroughs in this cutting-edge field.
cancel
Showing results for 
Search instead for 
Did you mean: 

DatabaseError (databricks.sql.exc.DatabaseError) Invalid SessionHandle in LangChain SQL chain

JUNNIE_J
New Contributor II

When creating a SQL Chatbot with LangChain SQLDatabase chain, Databricks database, and OpenAI model, I got a "Invalid SessionHandle" Error.

Code of creating the SQL Chain:

<code>

llm = ChatOpenAI(temperature=0, openai_api_key=api_key, model_name='gpt-4-0125-preview')
def get_db(_=None😞
    db = SQLDatabase.from_databricks(catalog="_", schema="_", host="_", api_token="_", cluster_id="_", sample_rows_in_table_info=3)
    return db
db = get_db()
def get_chain():
    db = get_db()
    chain = SQLDatabaseChain.from_llm(llm=llm, db=db, verbose=True)
    return chain
chain = get_chain()
</code>
 
Code of deploying on MLflow:
<code>
mlflow.set_registry_uri("databricks-uc")
model_name = f"SQL_chain"

with mlflow.start_run(run_name="sql_chain") as run:
    user_query = "..."
    answer = chain.invoke(user_query)
    answer_json = json.dumps(answer)
    signature = infer_signature(user_query, answer_json)
    model_info = mlflow.langchain.log_model(
        chain,
        loader_fn=get_db,
        artifact_path="chain",
        registered_model_name=model_name,
        pip_requirements=[
            f"mlflow=={mlflow.__version__}",
            f"langchain=={langchain.__version__}",
            f"langchain_community=={langchain_community.__version__}",
            f"langchain_experimental=={langchain_experimental.__version__}",
            f"openai=={openai.__version__}",
            f"langchain_core=={langchain_core.__version__}",
            f"databricks",
            f"databricks-sql-connector==2.9.3",
            ],
        input_example=user_query,
        signature=signature
    )
</code>
2 REPLIES 2

Kaniz_Fatma
Community Manager
Community Manager

Hi @JUNNIE_J,

I have tried the solutions. But they don't work.

When i tried :

from pyspark.sql import SparkSession
from databricks import sql

def get_db(_=None):
db = SQLDatabase.from_databricks(...)

spark = SparkSession.builder.appName("NewSession").getOrCreate()
sql_context = sql.Context(spark.sparkContext)
sql_context.sessionState().newSession()

return db

 

 

It returned : AttributeError: module 'databricks.sql' has no attribute 'Context'.

When I tried :

def get_chain():
global db
if db is None or not db.is_valid():
db = get_db()
chain = SQLDatabaseChain.from_llm(llm=llm, db=db, verbose=True)
return chain

 

 

It returned: AttributeError: 'SQLDatabase' object has no attribute 'is_valid'.

Join 100K+ Data Experts: Register Now & Grow with Us!

Excited to expand your horizons with us? Click here to Register and begin your journey to success!

Already a member? Login and join your local regional user group! If there isn’t one near you, fill out this form and we’ll create one for you to join!