Save HTML Form Into Database With Python Flask (Simple Example)

Welcome to a tutorial on how to save an HTML form into the database with Python Flask and SQLite. Just started with Python Flask and want to save a submitted form into the database? Well, it actually pretty easy – Read on for an example!

ⓘ I have included a zip file with all the source code at the start of this tutorial, so you don’t have to copy-paste everything… Or if you just want to dive straight in.

 

 

TLDR – QUICK SLIDES

Fullscreen Mode – Click Here

 

TABLE OF CONTENTS

 

 

QUICK NOTES

• Create a project folder, e.g. D:\save, unzip the code inside this folder.
• Navigate to the project folder in the command line cd D:\save, create a virtual environment to not mess up your other projects.
  • virtualenv venv
  • Windows – venv\scripts\activate
  • Mac/Linux – venv/bin/activate
• Get all the packages – pip install flask
• Create the database python S1B_create.py
• Launch! python S3_server.py and access http://localhost.

If you spot a bug, feel free to comment below. I try to answer short questions too, but it is one person versus the entire world… If you need answers urgently, please check out my list of websites to get help with programming.

 

SCREENSHOT

 

EXAMPLE CODE DOWNLOAD

Click here to download all the example source code, I have released it under the MIT license, so feel free to build on top of it or use it in your own project.

 

 

 

STEP 1) THE DATABASE

1A) DUMMY DATABASE TABLE

CREATE TABLE dummy (
  id INTEGER,
  email TEXT NOT NULL,
  txt TEXT NOT NULL,
  PRIMARY KEY("id" AUTOINCREMENT)
);

Let us start with a dummy database to work with, just a very simple one with 3 fields.

• id Primary key, auto-increment.
• email The user email.
• txt Whatever random text/content.

 

1B) CREATE THE DATABASE

# (A) LOAD PACKAGES
import sqlite3, os
from sqlite3 import Error

# (B) DATABASE + SQL FILE
DBFILE = "dummy.db"
SQLFILE = "S1A_dummy.sql"

# (C) DELETE OLD DATABASE IF EXIST
if os.path.exists(DBFILE):
  os.remove(DBFILE)

# (D) IMPORT SQL
conn = sqlite3.connect(DBFILE)
with open(SQLFILE) as f:
  conn.executescript(f.read())
conn.commit()
conn.close()
print("Database created!")

Next, this should be self-explanatory – We read the SQL file and create the actual database itself.

 

 

STEP 2) HTML FORM

<form method="post">
  <label>Email</label>
  <input type="email" name="email" required value="jon@doe.com">
  <label>Text</label>
  <input type="text" name="txt" required value="It works!">
  <input type="submit" value="Go!">
</form>

Don’t think this needs much explanation… Just a “regular Joe” HTML form.

 

 

STEP 3) FLASK SERVER

# (A) INIT
# (A1) LOAD MODULES
from flask import Flask, render_template, request
import sqlite3
 
# (A2) FLASK SETTINGS + INIT
HOST_NAME = "localhost"
HOST_PORT = 80
app = Flask(__name__)
# app.debug = True

# (B) DUMMY PAGE
@app.route("/", methods=["GET", "POST"])
def index():
  # (B1) SAVE ON FORM SUBMIT
  if request.method == "POST":
    conn = sqlite3.connect("dummy.db")
    cursor = conn.cursor()
    cursor.execute("INSERT INTO dummy (`email`, `txt`) VALUES (?,?)", (request.values.get("email"), request.values.get("txt")))
    conn.commit()
    conn.close()
 
  # (B2) RENDER PAGE
  return render_template("S2_form.html")
  
# (C) START
if __name__ == "__main__":
  app.run(HOST_NAME, HOST_PORT)

1. Load the required modules (Flask and SQLite), plus a bunch of settings.
2. Take note of how this works.
   • (B2) When “accessed normally”, we serve the above HTML form.
   • (B1) When the form is submitted, we save it into the database.
3. Start the Flask server.

 

 

 

A FEW MORE NOTES

Yes, saving an HTML form is that simple, but a couple of things to take note of:

• SQLite is a great tool for learning, but it is better to use a “professional database” for production servers.
• PostgreSQL, MySQL, Redis, or MongoDB – Pick your poison. Best to learn at least one.
• To show a saved/error message in the HTML, we can pass variables into the template. A quick pseudo-code snippet:
  • message = ""
  • try: SAVE INTO DATABASE, THEN message = "OK"
  • except: message = "ERROR MESSAGE"
  • render_template("S2_form.html", message)

 

LINKS & REFERENCES

• Python Flask
• SQLite
• Jinja (HTML Template System)

 

INFOGRAPHIC CHEAT SHEET