main.py

import streamlit as st
import sqlite3
import pandas as pd

def create_table():
    conn = sqlite3.connect('users.db')
    c = conn.cursor()
    c.execute('''
        CREATE TABLE IF NOT EXISTS users(
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            name TEXT,
            email TEXT,
            age INTEGER
        )
    ''')
    conn.commit()
    conn.close()

def add_user(name, email, age):
    conn = sqlite3.connect('users.db')
    c = conn.cursor()
    c.execute('INSERT INTO users (name, email, age) VALUES (?, ?, ?)', (name, email, age))
    conn.commit()
    conn.close()

def view_users():
    conn = sqlite3.connect('users.db')
    c = conn.cursor()
    c.execute('SELECT * FROM users')
    data = c.fetchall()
    conn.close()
    return data

def delete_user(user_id):
    conn = sqlite3.connect('users.db')
    c = conn.cursor()
    c.execute('DELETE FROM users WHERE id=?', (user_id,))
    conn.commit()
    conn.close()

st.title("👥 User Management App")

st.sidebar.header("Navigation")
menu = ["Add User", "View Users", "Delete User"]
choice = st.sidebar.selectbox("Select an Option", menu)

st.sidebar.markdown("---")
st.sidebar.markdown("**Developed by Cate Tuazon**")
st.sidebar.markdown("_User Database powered by SQLite_")

create_table()

if choice == "Add User":
    st.subheader("➕ Add New User")
    name = st.text_input("Name")
    email = st.text_input("Email")
    age = st.number_input("Age", 0, 120)
    if st.button("Submit"):
        if name and email:
            add_user(name, email, age)
            st.success(f"{name} added successfully!")
        else:
            st.error("Please fill out all fields.")

elif choice == "View Users":
    st.subheader("📋 View All Users")
    users = view_users()
    df = pd.DataFrame(users, columns=["ID", "Name", "Email", "Age"])
    st.dataframe(df)

elif choice == "Delete User":
    st.subheader("🗑️ Delete a User")
    users = view_users()
    df = pd.DataFrame(users, columns=["ID", "Name", "Email", "Age"])
    st.dataframe(df)
    user_id = st.number_input("Enter User ID to Delete", min_value=1, step=1)
    if st.button("Delete"):
        delete_user(user_id)
        st.warning(f"User {user_id} deleted!")