Creating Tables

Now that you have a database, you need a place to store data.

This is done using tables.

What is a Table?

A table is where your data is stored.

Think of it like a spreadsheet with columns and rows.

You will now create your first table.

What You Will Do

You will:

• Create a table called users
• Define columns for the data
• Save the table in your database

Step 1: Open database.py

Update your file to this:

import sqlite3

conn = sqlite3.connect("database.db")
cursor = conn.cursor()

# create table
cursor.execute("""
CREATE TABLE users (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT
)
""")

conn.commit()
conn.close()

print("Table created successfully")

Step 2: Run the File

python database.py

What Just Happened?

• A table named users was created

• It has two columns:

  • id → unique number for each user
  • name → stores the user’s name

Important Concepts

PRIMARY KEY

• Uniquely identifies each row
• No two rows can have the same id

AUTOINCREMENT

• Automatically increases the id
• You don’t need to set it manually

Step 3: Avoid Duplicate Errors

If you run the script again, you may get an error:

table already exists

Fix this by updating your code:

cursor.execute("""
CREATE TABLE IF NOT EXISTS users (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT
)
""")

Why This Matters

You now have:

• A database file
• A table to store data

Next, you will start adding real data.

Common Mistakes

• ❌ Forgetting conn.commit()
• ❌ Running without IF NOT EXISTS
• ❌ Typos in SQL

Summary

• Tables store your data
• You created a users table
• You defined columns

In the next lesson, you will insert data into your table.