I cannot create new tables for migration - mysql

Question

I am running
./yii migrate/create create_junction_table_for_sales_and_branch_tables --fields="created_at:dateTime"
and I get the following error:
Error: SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: nodename nor servname provided, or not known.
Trying to create an ordinary table also gives the same error. I cannot solve this issue.
This is part of my code in common/config/main.php:
'components' => [
'db' => [
'class' => 'yii\db\Connection',
'dsn' => 'mysql:host=' . getenv('DB_HOST') . ';port='.
getenv('DB_PORT', 3306) .';dbname=' . getenv('DB_NAME'),
'username' => getenv('DB_USERNAME'),
'password' => getenv('DB_PASSWORD'),
'charset' => 'utf8',
],

Answer 1

The best way to configure your db connection is:
return [
'class' => \yii\db\Connection::class,
'dsn' => 'mysql:host=address:port;dbname=mydatabase',
'username' => 'admin',
'password' => '123321',
'charset' => 'utf8',
];
Also you can define variables in yor cfg file, and use them, don't forget, that env.variables, which you are using, must be defined in your environment
// You may define env.variable in your system.
$host = 'localhost';
$port = '3306';
$dbname = 'mydatabase';
$username = 'admin';
$password = '123321';
$charset = 'utf8';
return [
'class' => \yii\db\Connection::class,
'dsn' => "mysql:host={$host}:{$port};dbname={$dbname}",
'username' => $username,
'password' => $password,
'charset' => $charset,
];
You can customize variables as you want, also you may write methods, before returning connection class, to get all needed variables.