system/Database/MySQLi/Connection.php
public function getVersion(): string
	{
		if (isset($this->dataCache['version']))
		{
			return $this->dataCache['version'];
		}

		if (empty($this->mysqli))
		{
			$this->initialize();
		}

		return $this->dataCache['version'] = $this->mysqli->server_info;
	}
public function getVersion(): string
	{
		if (isset($this->dataCache['version']))
		{
			return $this->dataCache['version'];
		}

		if (empty($this->mysqli))
		{
			$this->initialize();
		}

		return $this->dataCache['version'] = $this->mysqli->server_info;
	}
Returns a string containing the version of the database being used.

@return string