Database Connection Guides

Express.js API Router

const express = require('express');
const { Pool } = require('pg');
const app = express();

const db = new Pool({
  connectionString: process.env.DATABASE_URL, // postgresql://user:pass@sql.mqzz.site:5432/dbname?sslmode=require
  ssl: { rejectUnauthorized: false }
});

app.get('/api/users', async (req, res) => {
  try {
    const { rows } = await db.query('SELECT id, name, email FROM users LIMIT 20');
    res.json({ success: true, data: rows });
  } catch (err) {
    res.status(500).json({ success: false, error: err.message });
  }
});

app.listen(3000, () => console.log('Server running on port 3000'));

Next.js App Router (Server Component / API Route)

// app/api/db-check/route.ts
import { NextResponse } from 'next/server';
import { Pool } from 'pg';

const pool = new Pool({
  connectionString: process.env.POSTGRES_URL,
  ssl: { rejectUnauthorized: false },
});

export async function GET() {
  const client = await pool.connect();
  try {
    const result = await client.query('SELECT version();');
    return NextResponse.json({ status: 'Connected', version: result.rows[0].version });
  } finally {
    client.release();
  }
}

Python with `psycopg2`

Install via: pip install psycopg2-binary

import psycopg2
import os

conn = psycopg2.connect(
    host="sql.mqzz.site",
    port=5432,
    dbname=os.getenv("PG_DATABASE"),
    user=os.getenv("PG_USER"),
    password=os.getenv("PG_PASSWORD"),
    sslmode="require"
)

cursor = conn.cursor()
cursor.execute("SELECT version();")
print("PostgreSQL Version:", cursor.fetchone())
cursor.close()
conn.close()

Django `settings.py` Configuration

# settings.py
import os

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': os.getenv('DB_NAME'),
        'USER': os.getenv('DB_USER'),
        'PASSWORD': os.getenv('DB_PASSWORD'),
        'HOST': 'sql.mqzz.site',
        'PORT': '5432',
        'OPTIONS': {
            'sslmode': 'require',
        },
        'CONN_MAX_AGE': 60,
    }
}

PHP 8.2+ with PDO PostgreSQL

<?php
$host = 'sql.mqzz.site';
$port = 5432;
$db   = getenv('PG_DATABASE');
$user = getenv('PG_USER');
$pass = getenv('PG_PASSWORD');

$dsn = "pgsql:host={$host};port={$port};dbname={$db};sslmode=require";
$options = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
];

try {
    $pdo = new PDO($dsn, $user, $pass, $options);
    $stmt = $pdo->query('SELECT NOW() AS current_time');
    print_r($stmt->fetch());
} catch (\PDOException $e) {
    throw new \PDOException($e->getMessage(), (int)$e->getCode());
}

Laravel `.env` & `config/database.php`

# .env
DB_CONNECTION=pgsql
DB_HOST=sql.mqzz.site
DB_PORT=5432
DB_DATABASE=mqzz_your_dbname
DB_USERNAME=usr_your_role
DB_PASSWORD=your_encrypted_password
DB_SSLMODE=require

# In config/database.php under 'pgsql':
# 'sslmode' => env('DB_SSLMODE', 'require'),

Java with JDBC Driver

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class MqzzDbConnect {
    public static void main(String[] args) {
        String url = "jdbc:postgresql://sql.mqzz.site:5432/YOUR_DBNAME?ssl=true&sslmode=require";
        String user = "YOUR_USERNAME";
        String password = "YOUR_PASSWORD";

        try (Connection con = DriverManager.getConnection(url, user, password);
             Statement st = con.createStatement();
             ResultSet rs = st.executeQuery("SELECT version()")) {
            if (rs.next()) {
                System.out.println("Connected: " + rs.getString(1));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Kotlin with HikariCP & Exposed / JDBC

import com.zaxxer.hikari.HikariConfig
import com.zaxxer.hikari.HikariDataSource

val config = HikariConfig().apply {
    jdbcUrl = "jdbc:postgresql://sql.mqzz.site:5432/mqzz_dbname?ssl=true&sslmode=require"
    username = "usr_role"
    password = "secret_password"
    maximumPoolSize = 10
}
val dataSource = HikariDataSource(config)

Android Architecture Pattern

⚠️ Secure Design: Android mobile apps must connect to an intermediate REST API (e.g. Express, FastAPI, Laravel) rather than connecting to raw database ports.

// Retrofit API Service in Kotlin/Android
interface MqzzBackendApi {
    @GET("api/v1/profile")
    suspend fun getProfile(@Header("Authorization") token: String): ProfileResponse
}

// Your backend server connects securely to:
// postgresql://user:pass@sql.mqzz.site:5432/dbname?sslmode=require

Flutter Cross-Platform Architecture

⚠️ Security Notice: Never package PostgreSQL database credentials inside APK or IPA files.

import 'package:http/http.dart' as http;

Future fetchAppData() async {
  // Mobile app requests secure backend
  final response = await http.get(Uri.parse('https://your-backend.com/api/items'));
  print(response.body);
}

// Your backend server connects safely to MQZZ.DB:
// postgresql://user:password@sql.mqzz.site:5432/mqzz_db?sslmode=require

React Applications via Secure Serverless / Backend

// In React Client:
import { useEffect, useState } from 'react';

export default function DataTable() {
  const [data, setData] = useState([]);

  useEffect(() => {
    // Call YOUR secure backend API (not direct database)
    fetch('/api/records')
      .then(res => res.json())
      .then(json => setData(json.data));
  }, []);

  return 
{data.map(item => 
{item.name}
)}
;
}