

# Introduction
Information has grow to be an indispensable useful resource for any profitable enterprise, because it gives helpful insights for knowledgeable decision-making. Given the significance of information, many corporations are constructing techniques to retailer and analyze it. Nonetheless, there are lots of instances when it’s onerous to accumulate and analyze the required information, particularly with the rising complexity of the info system.
With the appearance of generative AI, information work has grow to be considerably simpler, as we are able to now use easy pure language to obtain principally correct output that carefully follows the enter we offer. It’s additionally relevant to information processing and evaluation with SQL, the place we are able to ask for question improvement.
On this article, we are going to develop a easy API utility that interprets pure language into SQL queries that our database understands. We are going to use three essential instruments: OpenAI, FastAPI, and SQLite.
Right here’s the plan.
# Textual content-to-SQL App Growth
First, we’ll put together every part wanted for our undertaking. All it is advisable to present is the OpenAI API key, which we’ll use to entry the generative mannequin. To containerize the appliance, we are going to use Docker, which you’ll be able to purchase for the native implementation utilizing Docker Desktop.
Different parts, resembling SQLite, will already be out there if you set up Python, and FastAPI might be put in later.
For the general undertaking construction, we are going to use the next:
text_to_sql_app/
├── app/
│ ├── __init__.py
│ ├── database.py
│ ├── openai_utils.py
│ └── essential.py
├── demo.db
├── init_db.sql
├── necessities.txt
├── Dockerfile
├── docker-compose.yml
├── .env
Create the construction like above, or you should utilize the next repository to make issues simpler. We are going to nonetheless undergo every file to achieve an understanding of the best way to develop the appliance.
Let’s begin by populating the .env
file with the OpenAI API key we beforehand acquired. You are able to do that with the next code:
OPENAI_API_KEY=YOUR-API-KEY
Then, go to the necessities.txt
to fill within the vital libraries we are going to use for
fastapi
uvicorn
sqlalchemy
openai
pydantic
python-dotenv
Subsequent, we transfer on to the __init__.py
file, and we are going to put the next code inside:
from pathlib import Path
from dotenv import load_dotenv
load_dotenv(dotenv_path=Path(__file__).resolve().father or mother.father or mother / ".env", override=False)
The code above ensures that the setting accommodates all the required keys we want.
Then, we are going to develop Python code within the database.py
file to connect with the SQLite database we are going to create later (referred to asdemo.db
) and supply a method to run SQL queries.
from sqlalchemy import create_engine, textual content
from sqlalchemy.orm import Session
ENGINE = create_engine("sqlite:///demo.db", future=True, echo=False)
def run_query(sql: str) -> record[dict]:
with Session(ENGINE) as session:
rows = session.execute(textual content(sql)).mappings().all()
return [dict(r) for r in rows]
After that, we are going to put together the openai_utils.py
file that can settle for the database schema and the enter questions. The output might be JSON containing the SQL question (with a guard to forestall any write operations).
import os
import json
from openai import OpenAI
shopper = OpenAI(api_key=os.getenv("OPENAI_API_KEY"))
_SYSTEM_PROMPT = """
You exchange natural-language questions into read-only SQLite SQL.
By no means output INSERT / UPDATE / DELETE.
Return JSON: { "sql": "..." }.
"""
def text_to_sql(query: str, schema: str) -> str:
response = shopper.chat.completions.create(
mannequin="gpt-4o-mini",
temperature=0.1,
response_format={"sort": "json_object"},
messages=[
{"role": "system", "content": _SYSTEM_PROMPT},
{"role": "user",
"content": f"schema:n{schema}nnquestion: {question}"}
]
)
payload = json.masses(response.selections[0].message.content material)
return payload["sql"]
With each the code and the connection prepared, we are going to put together the appliance utilizing FastAPI. The applying will settle for pure language questions and the database schema, convert them into SQL SELECT
queries, run them via the SQLite database, and return the outcomes as JSON. The applying might be an API we are able to entry through the CLI.
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from sqlalchemy import examine
from .database import ENGINE, run_query
from .openai_utils import text_to_sql
app = FastAPI(title="Textual content-to-SQL Demo")
class NLRequest(BaseModel):
query: str
@app.on_event("startup")
def capture_schema() -> None:
insp = examine(ENGINE)
world SCHEMA_STR
SCHEMA_STR = "n".be a part of(
f"CREATE TABLE {t} ({', '.be a part of(c['name'] for c in insp.get_columns(t))});"
for t in insp.get_table_names()
)
@app.submit("/question")
def question(req: NLRequest):
strive:
sql = text_to_sql(req.query, SCHEMA_STR)
if not sql.lstrip().decrease().startswith("choose"):
increase ValueError("Solely SELECT statements are allowed")
return {"sql": sql, "outcome": run_query(sql)}
besides Exception as e:
increase HTTPException(status_code=400, element=str(e))
That’s every part we want for the primary utility. The following factor we are going to put together is the database. Use the database under within the init_db.sql
for instance functions, however you’ll be able to all the time change it if you would like.
DROP TABLE IF EXISTS order_items;
DROP TABLE IF EXISTS orders;
DROP TABLE IF EXISTS funds;
DROP TABLE IF EXISTS merchandise;
DROP TABLE IF EXISTS prospects;
CREATE TABLE prospects (
id INTEGER PRIMARY KEY,
title TEXT NOT NULL,
nation TEXT,
signup_date DATE
);
CREATE TABLE merchandise (
id INTEGER PRIMARY KEY,
title TEXT NOT NULL,
class TEXT,
worth REAL
);
CREATE TABLE orders (
id INTEGER PRIMARY KEY,
customer_id INTEGER,
order_date DATE,
complete REAL,
FOREIGN KEY (customer_id) REFERENCES prospects(id)
);
CREATE TABLE order_items (
order_id INTEGER,
product_id INTEGER,
amount INTEGER,
unit_price REAL,
PRIMARY KEY (order_id, product_id),
FOREIGN KEY (order_id) REFERENCES orders(id),
FOREIGN KEY (product_id) REFERENCES merchandise(id)
);
CREATE TABLE funds (
id INTEGER PRIMARY KEY,
order_id INTEGER,
payment_date DATE,
quantity REAL,
methodology TEXT,
FOREIGN KEY (order_id) REFERENCES orders(id)
);
INSERT INTO prospects (id, title, nation, signup_date) VALUES
(1,'Alice','USA','2024-01-05'),
(2,'Bob','UK','2024-03-10'),
(3,'Choi','KR','2024-06-22'),
(4,'Dara','ID','2025-01-15');
INSERT INTO merchandise (id, title, class, worth) VALUES
(1,'Laptop computer Professional','Electronics',1500.00),
(2,'Noise-Canceling Headphones','Electronics',300.00),
(3,'Standing Desk','Furnishings',450.00),
(4,'Ergonomic Chair','Furnishings',250.00),
(5,'Monitor 27"','Electronics',350.00);
INSERT INTO orders (id, customer_id, order_date, complete) VALUES
(1,1,'2025-02-01',1850.00),
(2,2,'2025-02-03',600.00),
(3,3,'2025-02-05',350.00),
(4,1,'2025-02-07',450.00);
INSERT INTO order_items (order_id, product_id, amount, unit_price) VALUES
(1,1,1,1500.00),
(1,2,1,300.00),
(1,5,1,350.00),
(2,3,1,450.00),
(2,4,1,250.00),
(3,5,1,350.00),
(4,3,1,450.00);
INSERT INTO funds (id, order_id, payment_date, quantity, methodology) VALUES
(1,1,'2025-02-01',1850.00,'Credit score Card'),
(2,2,'2025-02-03',600.00,'PayPal'),
(3,3,'2025-02-05',350.00,'Credit score Card'),
(4,4,'2025-02-07',450.00,'Financial institution Switch');
Then, run the next code in your CLI to create a SQLite database for our undertaking.
sqlite3 demo.db < init_db.sql
With the database prepared, we are going to create a Dockerfile
to containerize our utility.
FROM python:3.12-slim
WORKDIR /code
COPY necessities.txt .
RUN pip set up --no-cache-dir -r necessities.txt
COPY . .
CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]
We will even create a docker-compose.yml
file for operating the appliance extra easily.
providers:
text2sql:
construct: .
env_file: .env
ports:
- "8000:8000"
restart: unless-stopped
volumes:
- ./demo.db:/code/demo.db
With every part prepared, begin your Docker Desktop and run the next code to construct the appliance.
docker compose construct --no-cache
docker compose up -d
If every part is finished nicely, you’ll be able to check the appliance by utilizing the next code. We are going to ask what number of prospects we’ve within the information.
curl -X POST "http://localhost:8000/question" -H "Content material-Kind: utility/json" -d "{"query":"What number of prospects?"}"
The output will appear like this.
{"sql":"SELECT COUNT(*) AS customer_count FROM prospects;","outcome":[{"customer_count":4}]}
We will strive one thing extra complicated, just like the variety of orders for every buyer:
curl -X POST "http://localhost:8000/question" -H "Content material-Kind: utility/json" -d "{"query":"What's the variety of orders positioned by every buyer"}"
With output like under.
{"sql":"SELECT customer_id, COUNT(*) AS number_of_orders FROM orders GROUP BY customer_id;","outcome":[{"customer_id":1,"number_of_orders":2},{"customer_id":2,"number_of_orders":1},{"customer_id":3,"number_of_orders":1}]}
That’s all it is advisable to construct a fundamental Textual content-to-SQL utility. You may improve it additional with a front-end interface and a extra complicated system tailor-made to your wants.
# Wrapping Up
Information is the center of any information work, and corporations use it to make selections. Many instances, the system we’ve is just too complicated, and we have to depend on generative AI to assist us navigate it.
On this article, we’ve realized the best way to develop a easy Textual content-to-SQL utility utilizing the OpenAI mannequin, FastAPI, and SQLite.
I hope this has helped!
Cornellius Yudha Wijaya is an information science assistant supervisor and information author. Whereas working full-time at Allianz Indonesia, he likes to share Python and information ideas through social media and writing media. Cornellius writes on a wide range of AI and machine studying subjects.