docs: update database connection with information on how to connect to a MySQL server over a socket

user_guide_src/source/database/configuration.rst

@@ -190,3 +190,19 @@ Explanation of Values:
     etc.) not all values will be needed. For example, when using ``SQLite3`` you
     will not need to supply a username or password, and the database name
     will be the path to your database file.
+
+MySQLi
+======
+
+hostname
+--------
+
+Configuring a Socket Connection
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+To connect to a MySQL server over a filesystem socket, the path to the socket should be specified in
+the ``'hostname'`` setting. CodeIgniter's MySQLi driver will notice this and configure the
+connection properly.
+
+.. literalinclude:: configuration/011.php
+    :lines: 11-18

user_guide_src/source/database/configuration/011.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Config;
+
+use CodeIgniter\Database\Config;
+
+class Database extends Config
+{
+    // ...
+
+    // MySQLi over a socket
+    public array $default = [
+        // ...
+        'hostname' => '/cloudsql/toolbox-tests:europe-north1:toolbox-db',
+        // ...
+        'DBDriver' => 'MySQLi',
+        // ...
+    ];
+
+    // ...
+}