fix: getVersion() for OCI8 driver when no connection is established

Author: michalsn

system/Database/OCI8/Connection.php

@@ -193,9 +193,14 @@ public function getVersion(): string
             return $this->dataCache['version'];
         }
 
-        if (! $this->connID || ($versionString = oci_server_version($this->connID)) === false) {
+        if ($this->connID === false) {
+            $this->initialize();
+        }
+
+        if (($versionString = oci_server_version($this->connID)) === false) {
             return '';
         }
+
         if (preg_match('#Release\s(\d+(?:\.\d+)+)#', $versionString, $match)) {
             return $this->dataCache['version'] = $match[1];
         }

tests/system/Database/Live/GetVersionTest.php

@@ -29,6 +29,12 @@ final class GetVersionTest extends CIUnitTestCase
 
     public function testGetVersion(): void
     {
+        if ($this->db->DBDriver === 'MySQLi') {
+            $this->db->mysqli = false;
+        }
+
+        $this->db->connID = false;
+
         $version = $this->db->getVersion();
 
         $this->assertMatchesRegularExpression('/\A\d+(\.\d+)*\z/', $version);

user_guide_src/source/changelogs/v4.6.1.rst

@@ -32,6 +32,7 @@ Bugs Fixed
 
 - **CURLRequest:** Fixed an issue where multiple header sections appeared in the CURL response body during multiple redirects from the target server.
 - **Cors:** Fixed a bug in the Cors filter that caused the appropriate headers to not be added when another filter returned a response object in the ``before`` filter.
+- **Database:** Fixed a bug in the ``OCI8`` driver where ``getVersion()`` returned an empty string when the database connection was not yet established.
 
 See the repo's
 `CHANGELOG.md <https://github.com/codeigniter4/CodeIgniter4/blob/develop/CHANGELOG.md>`_