How to handle the variables specific to the environment you use: Development, QA, Production, etc. WHAT are the, WHY should you use them, WHERE do you put them, and HOW are they used. As an added bonus, Environmental Variables are not limited to PHP!

1. ENVIRONMENTAL VARIABLES

2. WHAT?
➤ Not tied to a language
➤ Not tied to an application
➤ Set in on the server

3. ENVIRONMENTS
➤ Local
➤ Dev
➤ QA
➤ Production

4. WHY?
➤ Different Credentials
➤ Security

5. HOW?
➤ Apache/Nginx
➤ system wide
➤ virtual hosts
➤ hosting company dashboard
➤ htaccess
➤ packages

6. <?php
require __DIR__ . '/../vendor/autoload.php';
$dotenv = new DotenvDotenv('../');
$dotenv->overload();
$dotenv->required(['DB_DNS', 'DB_NAME', 'DB_USER', 'DB_PASS']);/**/
phpinfo();
/*$_ENV['DB_NAME'] = 'env';
$_ENV['DB_USER'] = 'env';
$_ENV['DB_PASS'] = '12345EnvP@ss';
$dsn = "mysql:dbname=" . $_ENV['DB_NAME'];/**/
try {
$db = new PDO($_ENV['DB_DNS'], getenv('DB_USER'),
getenv('DB_PASS'));
$db->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);
} catch (Exception $e) {
echo $e->getMessage();
exit;
}
var_dump($db->query("SELECT * FROM custom_vars")->fetchAll());

7. .ENV FILE
DB_NAME="env"
DB_USER="env"
DB_PASS=“12345EnvP@ss"
#Nesting Variables
DB_DNS=“mysql:dbname=${DB_NAME}"

8. COMMAND LINE
source .env && mysqldump -
u$MYSQL_USER -p$MYSQL_PASSWORD -
h$MYSQL_HOST $MYSQL_DATABASE >
$DUMP_FILE