diff --git a/adminer/drivers/mongo.inc.php b/adminer/drivers/mongo.inc.php
index d61365d6..a400c2e1 100644
--- a/adminer/drivers/mongo.inc.php
+++ b/adminer/drivers/mongo.inc.php
@@ -53,14 +53,15 @@ if (isset($_GET["mongo"])) {
 		}
 
 		class Result {
-			var $num_rows, $_rows = array(), $_offset = 0, $_charset = array();
+			var $num_rows;
+			private $rows = array(), $offset = 0, $charset = array();
 
 			function __construct($result) {
 				foreach ($result as $item) {
 					$row = array();
 					foreach ($item as $key => $val) {
 						if (is_a($val, 'MongoDB\BSON\Binary')) {
-							$this->_charset[$key] = 63;
+							$this->charset[$key] = 63;
 						}
 						$row[$key] =
 							(is_a($val, 'MongoDB\BSON\ObjectID') ? 'MongoDB\BSON\ObjectID("' . "$val\")" :
@@ -71,26 +72,26 @@ if (isset($_GET["mongo"])) {
 							$val // MongoMinKey, MongoMaxKey
 						)))));
 					}
-					$this->_rows[] = $row;
+					$this->rows[] = $row;
 					foreach ($row as $key => $val) {
-						if (!isset($this->_rows[0][$key])) {
-							$this->_rows[0][$key] = null;
+						if (!isset($this->rows[0][$key])) {
+							$this->rows[0][$key] = null;
 						}
 					}
 				}
-				$this->num_rows = count($this->_rows);
+				$this->num_rows = count($this->rows);
 			}
 
 			function fetch_assoc() {
-				$row = current($this->_rows);
+				$row = current($this->rows);
 				if (!$row) {
 					return $row;
 				}
 				$return = array();
-				foreach ($this->_rows[0] as $key => $val) {
+				foreach ($this->rows[0] as $key => $val) {
 					$return[$key] = $row[$key];
 				}
-				next($this->_rows);
+				next($this->rows);
 				return $return;
 			}
 
@@ -103,11 +104,11 @@ if (isset($_GET["mongo"])) {
 			}
 
 			function fetch_field() {
-				$keys = array_keys($this->_rows[0]);
-				$name = $keys[$this->_offset++];
+				$keys = array_keys($this->rows[0]);
+				$name = $keys[$this->offset++];
 				return (object) array(
 					'name' => $name,
-					'charsetnr' => $this->_charset[$name],
+					'charsetnr' => $this->charset[$name],
 				);
 			}
 		}
diff --git a/adminer/drivers/mssql.inc.php b/adminer/drivers/mssql.inc.php
index a5136c2b..93d00541 100644
--- a/adminer/drivers/mssql.inc.php
+++ b/adminer/drivers/mssql.inc.php
@@ -13,7 +13,8 @@ if (isset($_GET["mssql"])) {
 	define('Adminer\DRIVER', "mssql");
 	if (extension_loaded("sqlsrv")) {
 		class Db {
-			var $extension = "sqlsrv", $_link, $_result, $server_info, $affected_rows, $errno, $error;
+			var $extension = "sqlsrv", $server_info, $affected_rows, $errno, $error;
+			private $link, $result;
 
 			function _get_error() {
 				$this->error = "";
@@ -38,14 +39,14 @@ if (isset($_GET["mssql"])) {
 				if ($db != "") {
 					$connection_info["Database"] = $db;
 				}
-				$this->_link = @sqlsrv_connect(preg_replace('~:~', ',', $server), $connection_info);
-				if ($this->_link) {
-					$info = sqlsrv_server_info($this->_link);
+				$this->link = @sqlsrv_connect(preg_replace('~:~', ',', $server), $connection_info);
+				if ($this->link) {
+					$info = sqlsrv_server_info($this->link);
 					$this->server_info = $info['SQLServerVersion'];
 				} else {
 					$this->_get_error();
 				}
-				return (bool) $this->_link;
+				return (bool) $this->link;
 			}
 
 			function quote($string) {
@@ -58,7 +59,7 @@ if (isset($_GET["mssql"])) {
 			}
 
 			function query($query, $unbuffered = false) {
-				$result = sqlsrv_query($this->_link, $query); //! , array(), ($unbuffered ? array() : array("Scrollable" => "keyset"))
+				$result = sqlsrv_query($this->link, $query); //! , array(), ($unbuffered ? array() : array("Scrollable" => "keyset"))
 				$this->error = "";
 				if (!$result) {
 					$this->_get_error();
@@ -68,9 +69,9 @@ if (isset($_GET["mssql"])) {
 			}
 
 			function multi_query($query) {
-				$this->_result = sqlsrv_query($this->_link, $query);
+				$this->result = sqlsrv_query($this->link, $query);
 				$this->error = "";
-				if (!$this->_result) {
+				if (!$this->result) {
 					$this->_get_error();
 					return false;
 				}
@@ -79,7 +80,7 @@ if (isset($_GET["mssql"])) {
 
 			function store_result($result = null) {
 				if (!$result) {
-					$result = $this->_result;
+					$result = $this->result;
 				}
 				if (!$result) {
 					return false;
@@ -92,7 +93,7 @@ if (isset($_GET["mssql"])) {
 			}
 
 			function next_result() {
-				return $this->_result ? sqlsrv_next_result($this->_result) : null;
+				return $this->result ? sqlsrv_next_result($this->result) : null;
 			}
 
 			function result($query, $field = 0) {
@@ -106,10 +107,11 @@ if (isset($_GET["mssql"])) {
 		}
 
 		class Result {
-			var $_result, $_offset = 0, $_fields, $num_rows;
+			var $num_rows;
+			private $result, $offset = 0, $fields;
 
 			function __construct($result) {
-				$this->_result = $result;
+				$this->result = $result;
 				// $this->num_rows = sqlsrv_num_rows($result); // available only in scrollable results
 			}
 
@@ -124,18 +126,18 @@ if (isset($_GET["mssql"])) {
 			}
 
 			function fetch_assoc() {
-				return $this->_convert(sqlsrv_fetch_array($this->_result, SQLSRV_FETCH_ASSOC));
+				return $this->_convert(sqlsrv_fetch_array($this->result, SQLSRV_FETCH_ASSOC));
 			}
 
 			function fetch_row() {
-				return $this->_convert(sqlsrv_fetch_array($this->_result, SQLSRV_FETCH_NUMERIC));
+				return $this->_convert(sqlsrv_fetch_array($this->result, SQLSRV_FETCH_NUMERIC));
 			}
 
 			function fetch_field() {
-				if (!$this->_fields) {
-					$this->_fields = sqlsrv_field_metadata($this->_result);
+				if (!$this->fields) {
+					$this->fields = sqlsrv_field_metadata($this->result);
 				}
-				$field = $this->_fields[$this->_offset++];
+				$field = $this->fields[$this->offset++];
 				$return = new \stdClass;
 				$return->name = $field["Name"];
 				$return->orgname = $field["Name"];
@@ -145,12 +147,12 @@ if (isset($_GET["mssql"])) {
 
 			function seek($offset) {
 				for ($i=0; $i < $offset; $i++) {
-					sqlsrv_fetch($this->_result); // SQLSRV_SCROLL_ABSOLUTE added in sqlsrv 1.1
+					sqlsrv_fetch($this->result); // SQLSRV_SCROLL_ABSOLUTE added in sqlsrv 1.1
 				}
 			}
 
 			function __destruct() {
-				sqlsrv_free_stmt($this->_result);
+				sqlsrv_free_stmt($this->result);
 			}
 		}
 
diff --git a/adminer/drivers/mysql.inc.php b/adminer/drivers/mysql.inc.php
index 691ff28b..560848fb 100644
--- a/adminer/drivers/mysql.inc.php
+++ b/adminer/drivers/mysql.inc.php
@@ -65,9 +65,9 @@ if (!defined('Adminer\DRIVER')) {
 				$server_info, ///< @var string server version
 				$affected_rows, ///< @var int number of affected rows
 				$errno, ///< @var int last error code
-				$error, ///< @var string last error message
-				$_link, $_result ///< @access private
+				$error ///< @var string last error message
 			;
+			private $link, $result;
 
 			/** Connect to server
 			* @param string
@@ -80,19 +80,19 @@ if (!defined('Adminer\DRIVER')) {
 					$this->error = lang('Disable %s or enable %s or %s extensions.', "'mysql.allow_local_infile'", "MySQLi", "PDO_MySQL");
 					return false;
 				}
-				$this->_link = @mysql_connect(
+				$this->link = @mysql_connect(
 					($server != "" ? $server : ini_get("mysql.default_host")),
 					("$server$username" != "" ? $username : ini_get("mysql.default_user")),
 					("$server$username$password" != "" ? $password : ini_get("mysql.default_password")),
 					true,
 					131072 // CLIENT_MULTI_RESULTS for CALL
 				);
-				if ($this->_link) {
-					$this->server_info = mysql_get_server_info($this->_link);
+				if ($this->link) {
+					$this->server_info = mysql_get_server_info($this->link);
 				} else {
 					$this->error = mysql_error();
 				}
-				return (bool) $this->_link;
+				return (bool) $this->link;
 			}
 
 			/** Sets the client character set
@@ -101,11 +101,11 @@ if (!defined('Adminer\DRIVER')) {
 			*/
 			function set_charset($charset) {
 				if (function_exists('mysql_set_charset')) {
-					if (mysql_set_charset($charset, $this->_link)) {
+					if (mysql_set_charset($charset, $this->link)) {
 						return true;
 					}
 					// the client library may not support utf8mb4
-					mysql_set_charset('utf8', $this->_link);
+					mysql_set_charset('utf8', $this->link);
 				}
 				return $this->query("SET NAMES $charset");
 			}
@@ -115,7 +115,7 @@ if (!defined('Adminer\DRIVER')) {
 			* @return string escaped string enclosed in '
 			*/
 			function quote($string) {
-				return "'" . mysql_real_escape_string($string, $this->_link) . "'";
+				return "'" . mysql_real_escape_string($string, $this->link) . "'";
 			}
 
 			/** Select database
@@ -123,7 +123,7 @@ if (!defined('Adminer\DRIVER')) {
 			* @return bool
 			*/
 			function select_db($database) {
-				return mysql_select_db($database, $this->_link);
+				return mysql_select_db($database, $this->link);
 			}
 
 			/** Send query
@@ -132,16 +132,16 @@ if (!defined('Adminer\DRIVER')) {
 			* @return mixed bool or Result
 			*/
 			function query($query, $unbuffered = false) {
-				$result = @($unbuffered ? mysql_unbuffered_query($query, $this->_link) : mysql_query($query, $this->_link)); // @ - mute mysql.trace_mode
+				$result = @($unbuffered ? mysql_unbuffered_query($query, $this->link) : mysql_query($query, $this->link)); // @ - mute mysql.trace_mode
 				$this->error = "";
 				if (!$result) {
-					$this->errno = mysql_errno($this->_link);
-					$this->error = mysql_error($this->_link);
+					$this->errno = mysql_errno($this->link);
+					$this->error = mysql_error($this->link);
 					return false;
 				}
 				if ($result === true) {
-					$this->affected_rows = mysql_affected_rows($this->_link);
-					$this->info = mysql_info($this->_link);
+					$this->affected_rows = mysql_affected_rows($this->link);
+					$this->info = mysql_info($this->link);
 					return true;
 				}
 				return new Result($result);
@@ -152,14 +152,14 @@ if (!defined('Adminer\DRIVER')) {
 			* @return bool
 			*/
 			function multi_query($query) {
-				return $this->_result = $this->query($query);
+				return $this->result = $this->query($query);
 			}
 
 			/** Get current resultset
 			* @return Result
 			*/
 			function store_result() {
-				return $this->_result;
+				return $this->result;
 			}
 
 			/** Fetch next resultset
@@ -180,21 +180,19 @@ if (!defined('Adminer\DRIVER')) {
 				if (!$result || !$result->num_rows) {
 					return false;
 				}
-				return mysql_result($result->_result, 0, $field);
+				return mysql_result($result->result, 0, $field);
 			}
 		}
 
 		class Result {
-			var
-				$num_rows, ///< @var int number of rows in the result
-				$_result, $_offset = 0 ///< @access private
-			;
+			var $num_rows; ///< @var int number of rows in the result
+			private $result, $offset = 0;
 
 			/** Constructor
 			* @param resource
 			*/
 			function __construct($result) {
-				$this->_result = $result;
+				$this->result = $result;
 				$this->num_rows = mysql_num_rows($result);
 			}
 
@@ -202,21 +200,21 @@ if (!defined('Adminer\DRIVER')) {
 			* @return array
 			*/
 			function fetch_assoc() {
-				return mysql_fetch_assoc($this->_result);
+				return mysql_fetch_assoc($this->result);
 			}
 
 			/** Fetch next row as numbered array
 			* @return array
 			*/
 			function fetch_row() {
-				return mysql_fetch_row($this->_result);
+				return mysql_fetch_row($this->result);
 			}
 
 			/** Fetch next field
 			* @return object properties: name, type, orgtable, orgname, charsetnr
 			*/
 			function fetch_field() {
-				$return = mysql_fetch_field($this->_result, $this->_offset++); // offset required under certain conditions
+				$return = mysql_fetch_field($this->result, $this->offset++); // offset required under certain conditions
 				$return->orgtable = $return->table;
 				$return->orgname = $return->name;
 				$return->charsetnr = ($return->blob ? 63 : 0);
@@ -226,7 +224,7 @@ if (!defined('Adminer\DRIVER')) {
 			/** Free result set
 			*/
 			function __destruct() {
-				mysql_free_result($this->_result);
+				mysql_free_result($this->result);
 			}
 		}
 
diff --git a/adminer/drivers/oracle.inc.php b/adminer/drivers/oracle.inc.php
index 5282a972..9d368844 100644
--- a/adminer/drivers/oracle.inc.php
+++ b/adminer/drivers/oracle.inc.php
@@ -7,7 +7,8 @@ if (isset($_GET["oracle"])) {
 	define('Adminer\DRIVER', "oracle");
 	if (extension_loaded("oci8")) {
 		class Db {
-			var $extension = "oci8", $_link, $_result, $server_info, $affected_rows, $errno, $error;
+			var $extension = "oci8", $server_info, $affected_rows, $errno, $error;
+			private $link, $result;
 			var $_current_db;
 
 			function _error($errno, $error) {
@@ -19,9 +20,9 @@ if (isset($_GET["oracle"])) {
 			}
 
 			function connect($server, $username, $password) {
-				$this->_link = @oci_new_connect($username, $password, $server, "AL32UTF8");
-				if ($this->_link) {
-					$this->server_info = oci_server_version($this->_link);
+				$this->link = @oci_new_connect($username, $password, $server, "AL32UTF8");
+				if ($this->link) {
+					$this->server_info = oci_server_version($this->link);
 					return true;
 				}
 				$error = oci_error();
@@ -39,10 +40,10 @@ if (isset($_GET["oracle"])) {
 			}
 
 			function query($query, $unbuffered = false) {
-				$result = oci_parse($this->_link, $query);
+				$result = oci_parse($this->link, $query);
 				$this->error = "";
 				if (!$result) {
-					$error = oci_error($this->_link);
+					$error = oci_error($this->link);
 					$this->errno = $error["code"];
 					$this->error = $error["message"];
 					return false;
@@ -61,11 +62,11 @@ if (isset($_GET["oracle"])) {
 			}
 
 			function multi_query($query) {
-				return $this->_result = $this->query($query);
+				return $this->result = $this->query($query);
 			}
 
 			function store_result() {
-				return $this->_result;
+				return $this->result;
 			}
 
 			function next_result() {
@@ -74,21 +75,22 @@ if (isset($_GET["oracle"])) {
 
 			function result($query, $field = 0) {
 				$result = $this->query($query);
-				if (!is_object($result) || !oci_fetch($result->_result)) {
+				if (!is_object($result) || !oci_fetch($result->result)) {
 					return false;
 				}
-				return oci_result($result->_result, $field + 1);
+				return oci_result($result->result, $field + 1);
 			}
 		}
 
 		class Result {
-			var $_result, $_offset = 1, $num_rows;
+			var $num_rows;
+			private $result, $offset = 1;
 
 			function __construct($result) {
-				$this->_result = $result;
+				$this->result = $result;
 			}
 
-			function _convert($row) {
+			private function convert($row) {
 				foreach ((array) $row as $key => $val) {
 					if (is_a($val, 'OCI-Lob')) {
 						$row[$key] = $val->load();
@@ -98,25 +100,25 @@ if (isset($_GET["oracle"])) {
 			}
 
 			function fetch_assoc() {
-				return $this->_convert(oci_fetch_assoc($this->_result));
+				return $this->convert(oci_fetch_assoc($this->result));
 			}
 
 			function fetch_row() {
-				return $this->_convert(oci_fetch_row($this->_result));
+				return $this->convert(oci_fetch_row($this->result));
 			}
 
 			function fetch_field() {
-				$column = $this->_offset++;
+				$column = $this->offset++;
 				$return = new \stdClass;
-				$return->name = oci_field_name($this->_result, $column);
+				$return->name = oci_field_name($this->result, $column);
 				$return->orgname = $return->name;
-				$return->type = oci_field_type($this->_result, $column);
+				$return->type = oci_field_type($this->result, $column);
 				$return->charsetnr = (preg_match("~raw|blob|bfile~", $return->type) ? 63 : 0); // 63 - binary
 				return $return;
 			}
 
 			function __destruct() {
-				oci_free_statement($this->_result);
+				oci_free_statement($this->result);
 			}
 		}
 
diff --git a/adminer/drivers/pgsql.inc.php b/adminer/drivers/pgsql.inc.php
index 62418c9b..a805a3c8 100644
--- a/adminer/drivers/pgsql.inc.php
+++ b/adminer/drivers/pgsql.inc.php
@@ -7,7 +7,8 @@ if (isset($_GET["pgsql"])) {
 	define('Adminer\DRIVER', "pgsql");
 	if (extension_loaded("pgsql")) {
 		class Db {
-			var $extension = "PgSQL", $_link, $_result, $_string, $_database = true, $server_info, $affected_rows, $error, $timeout;
+			var $extension = "PgSQL", $server_info, $affected_rows, $error, $timeout;
+			private $link, $result, $string, $database = true;
 
 			function _error($errno, $error) {
 				if (ini_bool("html_errors")) {
@@ -21,28 +22,28 @@ if (isset($_GET["pgsql"])) {
 				global $adminer;
 				$db = $adminer->database();
 				set_error_handler(array($this, '_error'));
-				$this->_string = "host='" . str_replace(":", "' port='", addcslashes($server, "'\\")) . "' user='" . addcslashes($username, "'\\") . "' password='" . addcslashes($password, "'\\") . "'";
+				$this->string = "host='" . str_replace(":", "' port='", addcslashes($server, "'\\")) . "' user='" . addcslashes($username, "'\\") . "' password='" . addcslashes($password, "'\\") . "'";
 				$ssl = $adminer->connectSsl();
 				if (isset($ssl["mode"])) {
-					$this->_string .= " sslmode='" . $ssl["mode"] . "'";
+					$this->string .= " sslmode='" . $ssl["mode"] . "'";
 				}
-				$this->_link = @pg_connect("$this->_string dbname='" . ($db != "" ? addcslashes($db, "'\\") : "postgres") . "'", PGSQL_CONNECT_FORCE_NEW);
-				if (!$this->_link && $db != "") {
+				$this->link = @pg_connect("$this->string dbname='" . ($db != "" ? addcslashes($db, "'\\") : "postgres") . "'", PGSQL_CONNECT_FORCE_NEW);
+				if (!$this->link && $db != "") {
 					// try to connect directly with database for performance
-					$this->_database = false;
-					$this->_link = @pg_connect("$this->_string dbname='postgres'", PGSQL_CONNECT_FORCE_NEW);
+					$this->database = false;
+					$this->link = @pg_connect("$this->string dbname='postgres'", PGSQL_CONNECT_FORCE_NEW);
 				}
 				restore_error_handler();
-				if ($this->_link) {
-					$version = pg_version($this->_link);
+				if ($this->link) {
+					$version = pg_version($this->link);
 					$this->server_info = $version["server"];
-					pg_set_client_encoding($this->_link, "UTF8");
+					pg_set_client_encoding($this->link, "UTF8");
 				}
-				return (bool) $this->_link;
+				return (bool) $this->link;
 			}
 
 			function quote($string) {
-				return pg_escape_literal($this->_link, $string);
+				return pg_escape_literal($this->link, $string);
 			}
 
 			function value($val, $field) {
@@ -50,30 +51,30 @@ if (isset($_GET["pgsql"])) {
 			}
 
 			function quoteBinary($string) {
-				return "'" . pg_escape_bytea($this->_link, $string) . "'";
+				return "'" . pg_escape_bytea($this->link, $string) . "'";
 			}
 
 			function select_db($database) {
 				global $adminer;
 				if ($database == $adminer->database()) {
-					return $this->_database;
+					return $this->database;
 				}
-				$return = @pg_connect("$this->_string dbname='" . addcslashes($database, "'\\") . "'", PGSQL_CONNECT_FORCE_NEW);
+				$return = @pg_connect("$this->string dbname='" . addcslashes($database, "'\\") . "'", PGSQL_CONNECT_FORCE_NEW);
 				if ($return) {
-					$this->_link = $return;
+					$this->link = $return;
 				}
 				return $return;
 			}
 
 			function close() {
-				$this->_link = @pg_connect("$this->_string dbname='postgres'");
+				$this->link = @pg_connect("$this->string dbname='postgres'");
 			}
 
 			function query($query, $unbuffered = false) {
-				$result = @pg_query($this->_link, $query);
+				$result = @pg_query($this->link, $query);
 				$this->error = "";
 				if (!$result) {
-					$this->error = pg_last_error($this->_link);
+					$this->error = pg_last_error($this->link);
 					$return = false;
 				} elseif (!pg_num_fields($result)) {
 					$this->affected_rows = pg_affected_rows($result);
@@ -89,11 +90,11 @@ if (isset($_GET["pgsql"])) {
 			}
 
 			function multi_query($query) {
-				return $this->_result = $this->query($query);
+				return $this->result = $this->query($query);
 			}
 
 			function store_result() {
-				return $this->_result;
+				return $this->result;
 			}
 
 			function next_result() {
@@ -106,45 +107,46 @@ if (isset($_GET["pgsql"])) {
 				if (!$result || !$result->num_rows) {
 					return false;
 				}
-				return pg_fetch_result($result->_result, 0, $field);
+				return pg_fetch_result($result->result, 0, $field);
 			}
 
 			function warnings() {
-				return h(pg_last_notice($this->_link)); // second parameter is available since PHP 7.1.0
+				return h(pg_last_notice($this->link)); // second parameter is available since PHP 7.1.0
 			}
 		}
 
 		class Result {
-			var $_result, $_offset = 0, $num_rows;
+			var $num_rows;
+			private $result, $offset = 0;
 
 			function __construct($result) {
-				$this->_result = $result;
+				$this->result = $result;
 				$this->num_rows = pg_num_rows($result);
 			}
 
 			function fetch_assoc() {
-				return pg_fetch_assoc($this->_result);
+				return pg_fetch_assoc($this->result);
 			}
 
 			function fetch_row() {
-				return pg_fetch_row($this->_result);
+				return pg_fetch_row($this->result);
 			}
 
 			function fetch_field() {
-				$column = $this->_offset++;
+				$column = $this->offset++;
 				$return = new \stdClass;
 				if (function_exists('pg_field_table')) {
-					$return->orgtable = pg_field_table($this->_result, $column);
+					$return->orgtable = pg_field_table($this->result, $column);
 				}
-				$return->name = pg_field_name($this->_result, $column);
+				$return->name = pg_field_name($this->result, $column);
 				$return->orgname = $return->name;
-				$return->type = pg_field_type($this->_result, $column);
+				$return->type = pg_field_type($this->result, $column);
 				$return->charsetnr = ($return->type == "bytea" ? 63 : 0); // 63 - binary
 				return $return;
 			}
 
 			function __destruct() {
-				pg_free_result($this->_result);
+				pg_free_result($this->result);
 			}
 		}
 
diff --git a/adminer/drivers/sqlite.inc.php b/adminer/drivers/sqlite.inc.php
index 5c3394a3..eb0a8b97 100644
--- a/adminer/drivers/sqlite.inc.php
+++ b/adminer/drivers/sqlite.inc.php
@@ -8,37 +8,38 @@ if (isset($_GET["sqlite"])) {
 	if (class_exists("SQLite3")) {
 
 		class SqliteDb {
-			var $extension = "SQLite3", $server_info, $affected_rows, $errno, $error, $_link;
+			var $extension = "SQLite3", $server_info, $affected_rows, $errno, $error;
+			private $link;
 
 			function __construct($filename) {
-				$this->_link = new \SQLite3($filename);
-				$version = $this->_link->version();
+				$this->link = new \SQLite3($filename);
+				$version = $this->link->version();
 				$this->server_info = $version["versionString"];
 			}
 
 			function query($query) {
-				$result = @$this->_link->query($query);
+				$result = @$this->link->query($query);
 				$this->error = "";
 				if (!$result) {
-					$this->errno = $this->_link->lastErrorCode();
-					$this->error = $this->_link->lastErrorMsg();
+					$this->errno = $this->link->lastErrorCode();
+					$this->error = $this->link->lastErrorMsg();
 					return false;
 				} elseif ($result->numColumns()) {
 					return new Result($result);
 				}
-				$this->affected_rows = $this->_link->changes();
+				$this->affected_rows = $this->link->changes();
 				return true;
 			}
 
 			function quote($string) {
 				return (is_utf8($string)
-					? "'" . $this->_link->escapeString($string) . "'"
+					? "'" . $this->link->escapeString($string) . "'"
 					: "x'" . reset(unpack('H*', $string)) . "'"
 				);
 			}
 
 			function store_result() {
-				return $this->_result;
+				return $this->result;
 			}
 
 			function result($query, $field = 0) {
@@ -46,38 +47,39 @@ if (isset($_GET["sqlite"])) {
 				if (!is_object($result)) {
 					return false;
 				}
-				$row = $result->_result->fetchArray();
+				$row = $result->result->fetchArray();
 				return $row ? $row[$field] : false;
 			}
 		}
 
 		class Result {
-			var $_result, $_offset = 0, $num_rows;
+			var $num_rows;
+			private $result, $offset = 0;
 
 			function __construct($result) {
-				$this->_result = $result;
+				$this->result = $result;
 			}
 
 			function fetch_assoc() {
-				return $this->_result->fetchArray(SQLITE3_ASSOC);
+				return $this->result->fetchArray(SQLITE3_ASSOC);
 			}
 
 			function fetch_row() {
-				return $this->_result->fetchArray(SQLITE3_NUM);
+				return $this->result->fetchArray(SQLITE3_NUM);
 			}
 
 			function fetch_field() {
-				$column = $this->_offset++;
-				$type = $this->_result->columnType($column);
+				$column = $this->offset++;
+				$type = $this->result->columnType($column);
 				return (object) array(
-					"name" => $this->_result->columnName($column),
+					"name" => $this->result->columnName($column),
 					"type" => $type,
 					"charsetnr" => ($type == SQLITE3_BLOB ? 63 : 0), // 63 - binary
 				);
 			}
 
 			function __desctruct() {
-				return $this->_result->finalize();
+				return $this->result->finalize();
 			}
 		}
 
@@ -115,7 +117,7 @@ if (isset($_GET["sqlite"])) {
 			}
 
 			function multi_query($query) {
-				return $this->_result = $this->query($query);
+				return $this->result = $this->query($query);
 			}
 
 			function next_result() {
diff --git a/adminer/include/pdo.inc.php b/adminer/include/pdo.inc.php
index bde1535c..9dc1858e 100644
--- a/adminer/include/pdo.inc.php
+++ b/adminer/include/pdo.inc.php
@@ -4,7 +4,8 @@ namespace Adminer;
 // PDO can be used in several database drivers
 if (extension_loaded('pdo')) {
 	abstract class PdoDb {
-		var $_result, $server_info, $affected_rows, $errno, $error, $pdo;
+		var $server_info, $affected_rows, $errno, $error, $pdo;
+		private $result;
 
 		function dsn($dsn, $username, $password, $options = array()) {
 			$options[\PDO::ATTR_ERRMODE] = \PDO::ERRMODE_SILENT;
@@ -38,12 +39,12 @@ if (extension_loaded('pdo')) {
 		}
 
 		function multi_query($query) {
-			return $this->_result = $this->query($query);
+			return $this->result = $this->query($query);
 		}
 
 		function store_result($result = null) {
 			if (!$result) {
-				$result = $this->_result;
+				$result = $this->result;
 				if (!$result) {
 					return false;
 				}
@@ -57,11 +58,11 @@ if (extension_loaded('pdo')) {
 		}
 
 		function next_result() {
-			if (!$this->_result) {
+			if (!$this->result) {
 				return false;
 			}
-			$this->_result->_offset = 0;
-			return @$this->_result->nextRowset(); // @ - PDO_PgSQL doesn't support it
+			$this->result->_offset = 0;
+			return @$this->result->nextRowset(); // @ - PDO_PgSQL doesn't support it
 		}
 
 		function result($query, $field = 0) {
diff --git a/adminer/include/tmpfile.inc.php b/adminer/include/tmpfile.inc.php
index 76fb3617..b75f478f 100644
--- a/adminer/include/tmpfile.inc.php
+++ b/adminer/include/tmpfile.inc.php
@@ -2,8 +2,7 @@
 namespace Adminer;
 
 class TmpFile {
-	var $handler;
-	var $size;
+	private $handler, $size;
 
 	function __construct() {
 		$this->handler = tmpfile();
diff --git a/editor/include/adminer.inc.php b/editor/include/adminer.inc.php
index 83353b87..cd1beb32 100644
--- a/editor/include/adminer.inc.php
+++ b/editor/include/adminer.inc.php
@@ -3,7 +3,7 @@ namespace Adminer;
 
 class Adminer {
 	var $operators = array("<=", ">=");
-	var $_values = array();
+	private $values = array();
 
 	function name() {
 		return "<a href='https://www.adminer.org/editor/'" . target_blank() . " id='h1'>" . lang('Editor') . "</a>";
@@ -175,7 +175,7 @@ ORDER BY ORDINAL_POSITION", null, "") as $row //! requires MySQL 5
 					$ids[$row[$key]] = q($row[$key]);
 				}
 				// uses constant number of queries to get the descriptions, join would be complex, multiple queries would be slow
-				$descriptions = $this->_values[$table];
+				$descriptions = $this->values[$table];
 				if (!$descriptions) {
 					$descriptions = get_key_vals("SELECT $id, $name FROM " . table($table) . " WHERE $id IN (" . implode(", ", $ids) . ")");
 				}
@@ -653,7 +653,7 @@ qsl('div').onclick = whisperClick;", "")
 
 	function _foreignKeyOptions($table, $column, $value = null) {
 		if (list($target, $id, $name) = $this->_foreignColumn(column_foreign_keys($table), $column)) {
-			$return = &$this->_values[$target];
+			$return = &$this->values[$target];
 			if ($return === null) {
 				$table_status = table_status($target);
 				$return = ($table_status["Rows"] > 1000 ? "" : array("" => "") + get_key_vals("SELECT $id, $name FROM " . table($target) . " ORDER BY 2"));
diff --git a/plugins/drivers/clickhouse.php b/plugins/drivers/clickhouse.php
index d933e832..8b246034 100644
--- a/plugins/drivers/clickhouse.php
+++ b/plugins/drivers/clickhouse.php
@@ -8,11 +8,12 @@ if (isset($_GET["clickhouse"])) {
 
 	if (ini_bool('allow_url_fopen')) {
 		class Db {
-			var $extension = "JSON", $server_info, $errno, $_result, $error, $_url;
+			var $extension = "JSON", $server_info, $errno, $error;
+			private $result, $url;
 			var $_db = 'default';
 
 			function rootQuery($db, $query) {
-				$file = @file_get_contents("$this->_url/?database=$db", false, stream_context_create(array('http' => array(
+				$file = @file_get_contents("$this->url/?database=$db", false, stream_context_create(array('http' => array(
 					'method' => 'POST',
 					'content' => $this->isQuerySelectLike($query) ? "$query FORMAT JSONCompact" : $query,
 					'header' => 'Content-type: application/x-www-form-urlencoded',
@@ -57,7 +58,7 @@ if (isset($_GET["clickhouse"])) {
 
 			function connect($server, $username, $password) {
 				preg_match('~^(https?://)?(.*)~', $server, $match);
-				$this->_url = ($match[1] ?: "http://") . urlencode($username) . ":" . urlencode($password) . "@$match[2]";
+				$this->url = ($match[1] ?: "http://") . urlencode($username) . ":" . urlencode($password) . "@$match[2]";
 				$return = $this->query('SELECT 1');
 				return (bool) $return;
 			}
@@ -72,11 +73,11 @@ if (isset($_GET["clickhouse"])) {
 			}
 
 			function multi_query($query) {
-				return $this->_result = $this->query($query);
+				return $this->result = $this->query($query);
 			}
 
 			function store_result() {
-				return $this->_result;
+				return $this->result;
 			}
 
 			function next_result() {
@@ -90,7 +91,8 @@ if (isset($_GET["clickhouse"])) {
 		}
 
 		class Result {
-			var $num_rows, $_rows, $columns, $meta, $_offset = 0;
+			var $num_rows, $columns, $meta;
+			private $rows, $offset = 0;
 
 			function __construct($result) {
 				foreach ($result['data'] as $item) {
@@ -98,28 +100,28 @@ if (isset($_GET["clickhouse"])) {
 					foreach ($item as $key => $val) {
 						$row[$key] = is_scalar($val) ? $val : json_encode($val, 256); // 256 - JSON_UNESCAPED_UNICODE
 					}
-					$this->_rows[] = $row;
+					$this->rows[] = $row;
 				}
 				$this->num_rows = $result['rows'];
 				$this->meta = $result['meta'];
 				$this->columns = array_column($this->meta, 'name');
-				reset($this->_rows);
+				reset($this->rows);
 			}
 
 			function fetch_assoc() {
-				$row = current($this->_rows);
-				next($this->_rows);
+				$row = current($this->rows);
+				next($this->rows);
 				return $row === false ? false : array_combine($this->columns, $row);
 			}
 
 			function fetch_row() {
-				$row = current($this->_rows);
-				next($this->_rows);
+				$row = current($this->rows);
+				next($this->rows);
 				return $row;
 			}
 
 			function fetch_field() {
-				$column = $this->_offset++;
+				$column = $this->offset++;
 				$return = new \stdClass;
 				if ($column < count($this->columns)) {
 					$return->name = $this->meta[$column]['name'];
diff --git a/plugins/drivers/elastic.php b/plugins/drivers/elastic.php
index a11dd64f..9ee0257e 100644
--- a/plugins/drivers/elastic.php
+++ b/plugins/drivers/elastic.php
@@ -9,7 +9,8 @@ if (isset($_GET["elastic"])) {
 	if (ini_bool('allow_url_fopen')) {
 
 		class Db {
-			var $extension = "JSON", $server_info, $errno, $error, $_url;
+			var $extension = "JSON", $server_info, $errno, $error;
+			private $url;
 
 			/**
 			 * @param string $path
@@ -18,7 +19,7 @@ if (isset($_GET["elastic"])) {
 			 * @return array|false
 			 */
 			function rootQuery($path, array $content = null, $method = 'GET') {
-				$file = @file_get_contents("$this->_url/" . ltrim($path, '/'), false, stream_context_create(array('http' => array(
+				$file = @file_get_contents("$this->url/" . ltrim($path, '/'), false, stream_context_create(array('http' => array(
 					'method' => $method,
 					'content' => $content !== null ? json_encode($content) : null,
 					'header' => $content !== null ? 'Content-Type: application/json' : array(),
@@ -78,7 +79,7 @@ if (isset($_GET["elastic"])) {
 			 */
 			function connect($server, $username, $password) {
 				preg_match('~^(https?://)?(.*)~', $server, $match);
-				$this->_url = ($match[1] ?: "http://") . urlencode($username) . ":" . urlencode($password) . "@$match[2]";
+				$this->url = ($match[1] ?: "http://") . urlencode($username) . ":" . urlencode($password) . "@$match[2]";
 				$return = $this->query('');
 				if ($return) {
 					$this->server_info = $return['version']['number'];
@@ -96,18 +97,19 @@ if (isset($_GET["elastic"])) {
 		}
 
 		class Result {
-			var $num_rows, $_rows;
+			var $num_rows;
+			private $rows;
 
 			function __construct($rows) {
 				$this->num_rows = count($rows);
-				$this->_rows = $rows;
+				$this->rows = $rows;
 
-				reset($this->_rows);
+				reset($this->rows);
 			}
 
 			function fetch_assoc() {
-				$return = current($this->_rows);
-				next($this->_rows);
+				$return = current($this->rows);
+				next($this->rows);
 
 				return $return;
 			}
diff --git a/plugins/drivers/firebird.php b/plugins/drivers/firebird.php
index 5049dd5f..c42a30f4 100644
--- a/plugins/drivers/firebird.php
+++ b/plugins/drivers/firebird.php
@@ -18,8 +18,9 @@ if (isset($_GET["firebird"])) {
 				$affected_rows,
 				$errno,
 				$error,
-				$_link, $_result
+				$_link
 			;
+			private $result;
 
 			function connect($server, $username, $password) {
 				$this->_link = ibase_connect($server, $username, $password);
@@ -58,11 +59,11 @@ if (isset($_GET["firebird"])) {
 			}
 
 			function multi_query($query) {
-				return $this->_result = $this->query($query);
+				return $this->result = $this->query($query);
 			}
 
 			function store_result() {
-				return $this->_result;
+				return $this->result;
 			}
 
 			function next_result() {
@@ -80,23 +81,24 @@ if (isset($_GET["firebird"])) {
 		}
 
 		class Result {
-			var $num_rows, $_result, $_offset = 0;
+			var $num_rows;
+			private $result, $offset = 0;
 
 			function __construct($result) {
-				$this->_result = $result;
+				$this->result = $result;
 				// $this->num_rows = ibase_num_rows($result);
 			}
 
 			function fetch_assoc() {
-				return ibase_fetch_assoc($this->_result);
+				return ibase_fetch_assoc($this->result);
 			}
 
 			function fetch_row() {
-				return ibase_fetch_row($this->_result);
+				return ibase_fetch_row($this->result);
 			}
 
 			function fetch_field() {
-				$field = ibase_field_info($this->_result, $this->_offset++);
+				$field = ibase_field_info($this->result, $this->offset++);
 				return (object) array(
 					'name' => $field['name'],
 					'orgname' => $field['name'],
@@ -106,7 +108,7 @@ if (isset($_GET["firebird"])) {
 			}
 
 			function __destruct() {
-				ibase_free_result($this->_result);
+				ibase_free_result($this->result);
 			}
 		}
 
diff --git a/plugins/drivers/simpledb.php b/plugins/drivers/simpledb.php
index 36cfb820..56a8eb81 100644
--- a/plugins/drivers/simpledb.php
+++ b/plugins/drivers/simpledb.php
@@ -8,7 +8,8 @@ if (isset($_GET["simpledb"])) {
 
 	if (class_exists('SimpleXMLElement') && ini_bool('allow_url_fopen')) {
 		class Db {
-			var $extension = "SimpleXML", $server_info = '2009-04-15', $error, $timeout, $next, $affected_rows, $_result;
+			var $extension = "SimpleXML", $server_info = '2009-04-15', $error, $timeout, $next, $affected_rows;
+			private $result;
 
 			function select_db($database) {
 				return ($database == "domain");
@@ -38,11 +39,11 @@ if (isset($_GET["simpledb"])) {
 			}
 
 			function multi_query($query) {
-				return $this->_result = $this->query($query);
+				return $this->result = $this->query($query);
 			}
 
 			function store_result() {
-				return $this->_result;
+				return $this->result;
 			}
 
 			function next_result() {
@@ -55,7 +56,8 @@ if (isset($_GET["simpledb"])) {
 		}
 
 		class Result {
-			var $num_rows, $_rows = array(), $_offset = 0;
+			var $num_rows;
+			private $rows = array(), $offset = 0;
 
 			function __construct($result) {
 				foreach ($result as $item) {
@@ -73,14 +75,14 @@ if (isset($_GET["simpledb"])) {
 							$row[$name] = $value;
 						}
 					}
-					$this->_rows[] = $row;
+					$this->rows[] = $row;
 					foreach ($row as $key => $val) {
-						if (!isset($this->_rows[0][$key])) {
-							$this->_rows[0][$key] = null;
+						if (!isset($this->rows[0][$key])) {
+							$this->rows[0][$key] = null;
 						}
 					}
 				}
-				$this->num_rows = count($this->_rows);
+				$this->num_rows = count($this->rows);
 			}
 
 			function _processValue($element) {
@@ -88,15 +90,15 @@ if (isset($_GET["simpledb"])) {
 			}
 
 			function fetch_assoc() {
-				$row = current($this->_rows);
+				$row = current($this->rows);
 				if (!$row) {
 					return $row;
 				}
 				$return = array();
-				foreach ($this->_rows[0] as $key => $val) {
+				foreach ($this->rows[0] as $key => $val) {
 					$return[$key] = $row[$key];
 				}
-				next($this->_rows);
+				next($this->rows);
 				return $return;
 			}
 
@@ -109,8 +111,8 @@ if (isset($_GET["simpledb"])) {
 			}
 
 			function fetch_field() {
-				$keys = array_keys($this->_rows[0]);
-				return (object) array('name' => $keys[$this->_offset++]);
+				$keys = array_keys($this->rows[0]);
+				return (object) array('name' => $keys[$this->offset++]);
 			}
 		}
 	}