Laravel – Why does "php artisan migrate" command resulted in "SQLSTATE[HY000] [2002] Connection refused" error?

In the database migrations section, on Laravel Bootcamp’s Build Chirper with Inertia, after I entered the command:

$ php artisan migrate

it threw an error:

IlluminateDatabaseQueryException

SQLSTATE[HY000] [2002] Connection refused (Connection: mysql, SQL: select * from information_schema.tables where table_schema = laravel and table_name = migrations and table_type = ‘BASE TABLE’)

I searched within Stack Overflow for previous instances of similar issue such as:

• SQLSTATE[HY000] [2002] Connection refused within Laravel homestead
• Laravel SQLSTATE[HY000] [2002] Connection refused
• Database Laravel php artisan migrate connection refused
• Laravel; "SQLSTATE[HY000] [2002] Connection refused"

From these questions, all of the highest scored answers suggested to edit the DB_HOST in the .env file from 127.0.0.1 to localhost.

However, after I edited my .env file and ran the command:

$ php artisan migrate

it threw a different error:

IlluminateDatabaseQueryException

SQLSTATE[HY000] [2002] No such file or directory (Connection: mysql, SQL: select * from information_schema.tables where table_schema = laravel and table_name = migrations and table_type = ‘BASE TABLE’)

Here’s a snippet of my .env file that might be related to Laravel database migrations:

...

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=laravel
DB_USERNAME=root
DB_PASSWORD=

...

Plus, some additional info:

• Laravel: 10.29.0
• PHP: 8.1.2
• Composer: 2.6.5
• Ubuntu: 22.04.3

Thus, why does "php artisan migrate" command resulted in "SQLSTATE[HY000] [2002] Connection refused" error? And what should I do to resolve this problem?