Thursday, October 16, 2025

From JSON to Dashboard: Visualizing DuckDB Queries in Streamlit with Plotly


From JSON to Dashboard: Visualizing DuckDB Queries in Streamlit with Plotly
Picture by Editor | ChatGPT

 

Introduction

 
Information is an organization’s most important useful resource, and insights from knowledge may make the distinction between revenue and failure. Nevertheless, uncooked knowledge is difficult to know, so we visualize it in dashboards so non-technical folks can higher navigate it.

Constructing a dashboard shouldn’t be easy, particularly when working with JSON knowledge. Fortunately, many Python libraries could be mixed to create a useful device.

On this article, we are going to learn to develop a dashboard utilizing Streamlit and Plotly to visualise DuckDB queries on knowledge from a JSON file.

Curious? Let’s get into it.

 

Dashboard Growth

 
Earlier than growing our dashboard, let’s be taught a bit concerning the instruments we are going to use.

First, JSON, or JavaScript Object Notation, is a text-based format for storing and transmitting knowledge utilizing key-value pairs and arrays. It’s a generally used format for APIs and knowledge interchange between techniques.

Subsequent, DuckDB is an open-source RDBMS (Relational Database Administration System) designed for analytical workloads. It’s an in-process on-line analytical processing (OLAP) SQL database that runs immediately within the Python course of with out the necessity to handle a separate server. It’s additionally optimized for quick execution, ultimate for knowledge evaluation with massive datasets.

Streamlit is usually used for dashboard growth. It’s an open-source framework for growing interactive knowledge net functions utilizing Python. To develop the dashboard, we don’t want to know HTML, CSS, or JavaScript.

We may even use pandas, a robust library for knowledge manipulation and evaluation in Python.

Lastly, Plotly is an open-source library for growing interactive graphs and charts. It may be built-in with dashboard growth libraries comparable to Streamlit.

That’s the essential rationalization of the instruments we are going to use. Let’s begin growing our JSON Dashboard. We’ll use the next construction, so attempt to create it as follows.

JSON_Dashboard/
├── knowledge/
│   └── pattern.json
├── app.py
└── necessities.txt

 

Subsequent, let’s fill the information with all of the required data. First, let’s have our JSON instance knowledge just like the one under. You possibly can all the time use your personal knowledge, however right here is an instance you should utilize.

[
  {"id": 1, "category": "Electronics", "region": "North", "sales": 100, "profit": 23.5, "date": "2024-01-15"},
  {"id": 2, "category": "Furniture", "region": "South", "sales": 150, "profit": 45.0, "date": "2024-01-18"},
  {"id": 3, "category": "Electronics", "region": "East", "sales": 70, "profit": 12.3, "date": "2024-01-20"},
  {"id": 4, "category": "Clothing", "region": "West", "sales": 220, "profit": 67.8, "date": "2024-01-25"},
  {"id": 5, "category": "Furniture", "region": "North", "sales": 130, "profit": 38.0, "date": "2024-02-01"},
  {"id": 6, "category": "Clothing", "region": "South", "sales": 180, "profit": 55.2, "date": "2024-02-05"},
  {"id": 7, "category": "Electronics", "region": "West", "sales": 90, "profit": 19.8, "date": "2024-02-10"},
  {"id": 8, "category": "Furniture", "region": "East", "sales": 160, "profit": 47.1, "date": "2024-02-12"},
  {"id": 9, "category": "Clothing", "region": "North", "sales": 200, "profit": 62.5, "date": "2024-02-15"},
  {"id": 10, "category": "Electronics", "region": "South", "sales": 110, "profit": 30.0, "date": "2024-02-20"}
]

 

Subsequent, we are going to fill the necessities.txt file with the libraries we are going to use for our dashboard growth.

streamlit
duckdb
pandas
plotly

 

Then, run the next code to put in the required libraries. It’s endorsed to make use of a digital surroundings when establishing the surroundings.

pip set up -r necessities.txt

 

As soon as every little thing is prepared, we are going to develop our dashboard. We’ll discover the appliance code step-by-step so you’ll be able to comply with the logic.

Let’s begin by importing the required libraries for our dashboard.

import streamlit as st
import duckdb
import pandas as pd
import plotly.categorical as px

 

Subsequent, we are going to arrange the connection we have to DuckDB.

@st.cache_resource
def get_conn():
    return duckdb.join()

 

The code above will cache the DuckDB connection so the Streamlit dashboard doesn’t have to reconnect when the dashboard reruns, which avoids any efficiency lag.

Then, we put together the code to learn the JSON knowledge utilizing the next code.

@st.cache_data
def load_data(path):
    df = pd.read_json(path, convert_dates=["date"])
    return df

 

Within the code above, we rework the JSON file right into a pandas DataFrame and cache the information so we don’t have to learn it once more when the filter modifications.

After the information loading and connection are prepared, we are going to hook up with DuckDB to retailer the JSON knowledge. You possibly can all the time change the information location and desk title.

conn = get_conn()
df_full = load_data("knowledge/pattern.json")
conn.execute("CREATE OR REPLACE TABLE gross sales AS SELECT * FROM df_full")

 

Within the code above, we register the DataFrame as an SQL desk named gross sales inside DuckDB. The desk can be refreshed from reminiscence on each rerun, as we’re not establishing persistence in a separate script.

That’s all for the backend; let’s put together the Streamlit dashboard. First, let’s put together the dashboard title and the sidebar filters.

st.title("From JSON to Dashboard: DuckDB SQL Visualizer")

st.sidebar.header("Filter Choices")
class = st.sidebar.multiselect("Choose Class:", df_full['category'].distinctive())
area = st.sidebar.multiselect("Choose Area:", df_full['region'].distinctive())
date_range = st.sidebar.date_input("Choose Date Vary:", [df_full['date'].min(), df_full['date'].max()])

 

The sidebar above will turn into a dynamic filter for the loaded knowledge, the place we are able to change the SQL question primarily based on these filters.

We then construct the SQL question based on the filters with the next code.

question = "SELECT * FROM gross sales WHERE TRUE"
if class:
    question += f" AND class IN {tuple(class)}"
if area:
    question += f" AND area IN {tuple(area)}"
question += f" AND date BETWEEN '{date_range[0]}' AND '{date_range[1]}'"

 

The question above is constructed dynamically primarily based on the consumer’s choice. We begin with a WHERE TRUE situation to simplify appending extra filters with AND.

With the question era prepared, we are going to present the question and the ensuing knowledge with the next code.

st.subheader("Generated SQL Question")
st.code(question, language="sql")

df = conn.execute(question).df()
st.subheader(f"Question Outcomes: {len(df)} rows")
st.dataframe(df)

 

The code above exhibits the SQL question used to retrieve knowledge from DuckDB and converts the end result right into a pandas DataFrame to show the filtered desk.

Lastly, we are going to put together the Plotly visualizations utilizing the filtered knowledge.

if not df.empty:
    col1, col2 = st.columns(2)

    with col1:
        st.markdown("### Scatter Plot: Gross sales vs Revenue by Area")
        scatter_fig = px.scatter(df, x="gross sales", y="revenue", colour="area", hover_data=["category", "date"])
        st.plotly_chart(scatter_fig, use_container_width=True)

    with col2:
        st.markdown("### Bar Chart: Complete Gross sales by Class")
        bar_fig = px.bar(df.groupby("class", as_index=False)["sales"].sum(), x="class", y="gross sales", text_auto=True)
        st.plotly_chart(bar_fig, use_container_width=True)

    st.markdown("### Line Chart: Every day Gross sales Pattern")
    line_fig = px.line(df.groupby("date", as_index=False)["sales"].sum(), x="date", y="gross sales")
    st.plotly_chart(line_fig, use_container_width=True)
else:
    st.warning("No knowledge discovered for the chosen filters.")

 

Within the code above, we create three completely different plots: a scatter plot, a bar chart, and a line chart. You possibly can all the time swap the chart kind based on your wants.

With all of the code prepared, we are going to run the next command to launch our Streamlit dashboard.

 

Now you can entry the dashboard, which appears just like the picture under.

Overview of the Streamlit dashboard interface with filter optionsOverview of the Streamlit dashboard interface with filter options
 

The plots will seem like the picture under.

Scatter plot and bar chart visualizations in the Streamlit dashboardScatter plot and bar chart visualizations in the Streamlit dashboard
 

Because the visualizations use Plotly, you’ll be able to navigate them interactively, as proven within the line chart under.

Interactive line chart showing daily sales trend in the Streamlit dashboardInteractive line chart showing daily sales trend in the Streamlit dashboard
 

That’s all it’s essential know. You possibly can all the time add extra complexity to the dashboard and even deploy it in what you are promoting.

 

Conclusion

 
Information is essentially the most useful useful resource an organization can have, and visualizing it in a dashboard is a manner for enterprise folks to realize insights. On this article, we discovered how one can develop a easy dashboard with Streamlit and Plotly whereas connecting to knowledge from a JSON file saved in DuckDB.

I hope this has helped!
 
 

Cornellius Yudha Wijaya is a knowledge science assistant supervisor and knowledge author. Whereas working full-time at Allianz Indonesia, he likes to share Python and knowledge suggestions through social media and writing media. Cornellius writes on a wide range of AI and machine studying matters.

Related Articles

LEAVE A REPLY

Please enter your comment!
Please enter your name here

Latest Articles

PHP Code Snippets Powered By : XYZScripts.com