tomevault-io Streamlit Snowflake connection
Connect your Streamlit app to Snowflake the right way.
Use st.connection
Always use st.connection("snowflake") instead of raw connectors.
import streamlit as st
conn = st.connection("snowflake")
# Query data
df = conn.query("SELECT * FROM my_table LIMIT 100")
st.dataframe(df)
Why st.connection:
- Automatic connection pooling
- Built-in caching
- Handles reconnection
- Works with st.secrets
Caller's rights connection (Streamlit 1.53+)
For apps running in Snowflake, use caller's rights to run queries with the viewer's permissions instead of the app owner's:
conn = st.connection("snowflake", type="snowflake-callers-rights")
This is useful when:
- Different users should see different data based on their Snowflake roles
- You want row-level security to apply based on the viewer
- You don't want the app to have elevated permissions
Cached queries
Use the built-in ttl parameter to cache query results:
from datetime import timedelta
conn = st.connection("snowflake")
# Cache for 10 minutes
df = conn.query("SELECT * FROM metrics", ttl=timedelta(minutes=10))
# Cache for 1 hour
df = conn.query("SELECT * FROM reference_data", ttl=3600)
Configure with st.secrets
Store credentials in .streamlit/secrets.toml (never commit this file).
CRITICAL: Derive the account and host values from the user's Snowflake CLI connection config. Run snow connection list and use the exact values. A wrong account will redirect to the wrong login page.
# .streamlit/secrets.toml
[connections.snowflake]
account = "ORGNAME-ACCTNAME" # from `snow connection list`
host = "myaccount.snowflakecomputing.com" # from `snow connection list` (include if present)
user = "your_user"
authenticator = "externalbrowser"
warehouse = "your_warehouse"
database = "your_database"
schema = "your_schema"
Add to .gitignore:
.streamlit/secrets.toml
Parameterized queries
Use parameters to prevent SQL injection:
conn = st.connection("snowflake")
# Safe: parameterized
df = conn.query(
"SELECT * FROM users WHERE region = :region",
params={"region": selected_region}
)
# UNSAFE: string formatting - don't do this
# df = conn.query(f"SELECT * FROM users WHERE region = '{selected_region}'")
Write data
Use the session for write operations:
conn = st.connection("snowflake")
session = conn.session()
# Write a dataframe
session.write_pandas(df, "MY_TABLE", auto_create_table=True)
# Execute statements
session.sql("INSERT INTO logs VALUES (:ts, :msg)", params={...}).collect()
Multiple connections
Define multiple connections in secrets:
# .streamlit/secrets.toml
[connections.snowflake]
account = "prod_account"
# ... prod credentials
[connections.snowflake_staging]
account = "staging_account"
# ... staging credentials
prod_conn = st.connection("snowflake")
staging_conn = st.connection("snowflake_staging")
Chat with Cortex
Build a chat interface using Snowflake Cortex LLMs:
import streamlit as st
from snowflake.cortex import complete
st.set_page_config(page_title="AI Assistant", page_icon=":sparkles:")
if "messages" not in st.session_state:
st.session_state.messages = []
for msg in st.session_state.messages:
with st.chat_message(msg["role"]):
st.write(msg["content"])
if prompt := st.chat_input("Ask anything"):
st.session_state.messages.append({"role": "user", "content": prompt})
with st.chat_message("user"):
st.write(prompt)
with st.chat_message("assistant"):
response = st.write_stream(
complete(
"claude-3-5-sonnet",
prompt,
session=st.connection("snowflake").session(),
stream=True,
)
)
st.session_state.messages.append({"role": "assistant", "content": response})
See building-streamlit-chat-ui for more chat patterns (avatars, suggestions, history management).
Python 3.12+ dependency caveat
streamlit[snowflake] gates snowflake-connector-python on python_version < "3.12". On Python 3.12+, the connector is silently skipped and you get No module named 'snowflake' at runtime. Always add snowflake-connector-python>=3.3.0 as an explicit dependency in pyproject.toml:
dependencies = [
"snowflake-connector-python>=3.3.0",
"streamlit[snowflake]>=1.54.0",
]
References
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