<?php
    define('DB_HOST', 'XXXXXX');
    define('DB_USER', 'postgres');
    define('DB_PASS', 'XXXXXX');
    define('DB_NAME', 'XXXXXXX');
    define('DB_PORT', '5432');
    //connection string with SSL certificate files
    $conn_str  = 'host=' . DB_HOST . ' ';
    $conn_str .= 'port=' . DB_PORT . ' ';
    $conn_str .= 'dbname=' . DB_NAME . ' ';
    $conn_str .= 'user=' . DB_USER . ' ';
    $conn_str .= 'password=' . DB_PASS . ' ';
    $conn_str .= 'sslmode=require ';
    $conn_str .= 'sslcert=/etc/apache2/ssl/postgresql.crt ';
    $conn_str .= 'sslkey=/etc/apache2/ssl/postgresql.key ';

    $conn = pg_connect($conn_str) or die('Cannot connect to database.');

    $sql = 'SELECT * FROM locations;';
    $result = pg_query($conn, $sql);

    if( $result ){
        while($row=pg_fetch_row($result)) {
            var_dump($row);
        }
    }

    pg_close();
    ?>