Help me with the databricks streamlit application related doubt

[gokkul]

Hi Databricks community ,

Hi I have a doubt regarding databricks streamlit application . I have a databricks streamlit application that takes input values from the user through streamlit UI. Now I want to store these input values in a delta table in Unity catalog . How can I proceed with this ? What are the requirements ? Do I need to  give any specific permissions to my databricks application's service principal inorder access the UC ?

[szymon_dybczak]

Hi @gokkul ,

Your app service principal needs to have a proper permission to write to UC table. You also need to use python databricks sdk to interact with UC object (i.e read/save a table).

You can get some inspiration from following databricks cookbook snippet. Here the app is reading from delta table. If you want to write you just need to use different method from python sdk:

import streamlit as st
from databricks import sql
from databricks.sdk.core import Config


cfg = Config()  # Set the DATABRICKS_HOST environment variable when running locally


@st.cache_resource(ttl="1h") # connection is cached
def get_connection(http_path):
    return sql.connect(
        server_hostname=cfg.host,
        http_path=http_path,
        credentials_provider=lambda: cfg.authenticate,
    )

def read_table(table_name, conn):
    with conn.cursor() as cursor:
        query = f"SELECT * FROM {table_name}"
        cursor.execute(query)
        return cursor.fetchall_arrow().to_pandas()

http_path_input = st.text_input(
    "Enter your Databricks HTTP Path:", placeholder="/sql/1.0/warehouses/xxxxxx"
)

table_name = st.text_input(
    "Specify a Unity Catalog table name:", placeholder="catalog.schema.table"
)

if http_path_input and table_name:
    conn = get_connection(http_path_input)
    df = read_table(table_name, conn)
    st.dataframe(df)