X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=include%2Fdba.php;h=fe191a9e21b3bf46f2043119b0d669a19b75c634;hb=755f6e8cc1ceb5fab0c0f63deb3ca7048d1ea48d;hp=16261efd2e02f3303c5df1fef0497b010ad78de1;hpb=cf90e3571fc6fdf6df26c2d368192a561ac0bd8a;p=friendica.git

diff --git a/include/dba.php b/include/dba.php
index 16261efd2e..fe191a9e21 100644
--- a/include/dba.php
+++ b/include/dba.php
@@ -1,36 +1,32 @@
 <?php
 use \Friendica\Core\System;
+use Friendica\Database\DBM;
 
-require_once("dbm.php");
 require_once('include/datetime.php');
 
 /**
  * @class MySQL database class
  *
- * For debugging, insert 'dbg(1);' anywhere in the program flow.
- * dbg(0); will turn it off. Logging is performed at LOGGER_DATA level.
- * When logging, all binary info is converted to text and html entities are escaped so that
- * the debugging stream is safe to view within both terminals and web pages.
- *
  * This class is for the low level database stuff that does driver specific things.
  */
 
 class dba {
-
-	private $debug = 0;
-	private $db;
-	private $result;
-	private $driver;
-	public  $connected = false;
-	public  $error = false;
-	public  $errorno = 0;
-	public  $affected_rows = 0;
-	private $_server_info = '';
+	public static $connected = true;
+
+	private static $_server_info = '';
+	private static $db;
+	private static $driver;
+	private static $error = false;
+	private static $errorno = 0;
+	private static $affected_rows = 0;
 	private static $in_transaction = false;
-	private static $dbo;
 	private static $relation = array();
 
-	function __construct($serveraddr, $user, $pass, $db, $install = false) {
+	public static function connect($serveraddr, $user, $pass, $db, $install = false) {
+		if (!is_null(self::$db)) {
+			return true;
+		}
+
 		$a = get_app();
 
 		$stamp1 = microtime(true);
@@ -50,24 +46,24 @@ class dba {
 		$db = trim($db);
 
 		if (!(strlen($server) && strlen($user))) {
-			$this->connected = false;
-			$this->db = null;
-			return;
+			self::$connected = false;
+			self::$db = null;
+			return false;
 		}
 
 		if ($install) {
 			if (strlen($server) && ($server !== 'localhost') && ($server !== '127.0.0.1')) {
 				if (! dns_get_record($server, DNS_A + DNS_CNAME + DNS_PTR)) {
-					$this->error = sprintf(t('Cannot locate DNS info for database server \'%s\''), $server);
-					$this->connected = false;
-					$this->db = null;
-					return;
+					self::$error = sprintf(t('Cannot locate DNS info for database server \'%s\''), $server);
+					self::$connected = false;
+					self::$db = null;
+					return false;
 				}
 			}
 		}
 
 		if (class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
-			$this->driver = 'pdo';
+			self::$driver = 'pdo';
 			$connect = "mysql:host=".$server.";dbname=".$db;
 
 			if (isset($port)) {
@@ -78,47 +74,35 @@ class dba {
 				$connect .= ";charset=".$a->config["system"]["db_charset"];
 			}
 			try {
-				$this->db = @new PDO($connect, $user, $pass);
-				$this->connected = true;
+				self::$db = @new PDO($connect, $user, $pass);
+				self::$connected = true;
 			} catch (PDOException $e) {
-				$this->connected = false;
+				self::$connected = false;
 			}
 		}
 
-		if (!$this->connected && class_exists('mysqli')) {
-			$this->driver = 'mysqli';
-			$this->db = @new mysqli($server, $user, $pass, $db, $port);
+		if (!self::$connected && class_exists('mysqli')) {
+			self::$driver = 'mysqli';
+			self::$db = @new mysqli($server, $user, $pass, $db, $port);
 			if (!mysqli_connect_errno()) {
-				$this->connected = true;
-
-				if (isset($a->config["system"]["db_charset"])) {
-					$this->db->set_charset($a->config["system"]["db_charset"]);
-				}
-			}
-		}
-
-		if (!$this->connected && function_exists('mysql_connect')) {
-			$this->driver = 'mysql';
-			$this->db = mysql_connect($serveraddr, $user, $pass);
-			if ($this->db && mysql_select_db($db, $this->db)) {
-				$this->connected = true;
+				self::$connected = true;
 
 				if (isset($a->config["system"]["db_charset"])) {
-					mysql_set_charset($a->config["system"]["db_charset"], $this->db);
+					self::$db->set_charset($a->config["system"]["db_charset"]);
 				}
 			}
 		}
 
 		// No suitable SQL driver was found.
-		if (!$this->connected) {
-			$this->db = null;
+		if (!self::$connected) {
+			self::$db = null;
 			if (!$install) {
 				system_unavailable();
 			}
 		}
 		$a->save_timestamp($stamp1, "network");
 
-		self::$dbo = $this;
+		return true;
 	}
 
 	/**
@@ -129,21 +113,18 @@ class dba {
 	 *
 	 * @return string
 	 */
-	public function server_info() {
-		if ($this->_server_info == '') {
-			switch ($this->driver) {
+	public static function server_info() {
+		if (self::$_server_info == '') {
+			switch (self::$driver) {
 				case 'pdo':
-					$this->_server_info = $this->db->getAttribute(PDO::ATTR_SERVER_VERSION);
+					self::$_server_info = self::$db->getAttribute(PDO::ATTR_SERVER_VERSION);
 					break;
 				case 'mysqli':
-					$this->_server_info = $this->db->server_info;
-					break;
-				case 'mysql':
-					$this->_server_info = mysql_get_server_info($this->db);
+					self::$_server_info = self::$db->server_info;
 					break;
 			}
 		}
-		return $this->_server_info;
+		return self::$_server_info;
 	}
 
 	/**
@@ -151,10 +132,10 @@ class dba {
 	 *
 	 * @return string
 	 */
-	public function database_name() {
-		$r = $this->q("SELECT DATABASE() AS `db`");
-
-		return $r[0]['db'];
+	public static function database_name() {
+		$ret = self::p("SELECT DATABASE() AS `db`");
+                $data = self::inArray($ret);
+		return $data[0]['db'];
 	}
 
 	/**
@@ -162,7 +143,7 @@ class dba {
 	 *
 	 * @param string $query The database query that will be analyzed
 	 */
-	public function log_index($query) {
+	private static function log_index($query) {
 		$a = get_app();
 
 		if (empty($a->config["system"]["db_log_index"])) {
@@ -179,15 +160,15 @@ class dba {
 			return;
 		}
 
-		$r = $this->q("EXPLAIN ".$query);
-		if (!dbm::is_result($r)) {
+		$r = self::p("EXPLAIN ".$query);
+		if (!DBM::is_result($r)) {
 			return;
 		}
 
 		$watchlist = explode(',', $a->config["system"]["db_log_index_watch"]);
 		$blacklist = explode(',', $a->config["system"]["db_log_index_blacklist"]);
 
-		foreach ($r AS $row) {
+		while ($row = dba::fetch($r)) {
 			if ((intval($a->config["system"]["db_loglimit_index"]) > 0)) {
 				$log = (in_array($row['key'], $watchlist) &&
 					($row['rows'] >= intval($a->config["system"]["db_loglimit_index"])));
@@ -214,73 +195,33 @@ class dba {
 		}
 	}
 
-	public function q($sql) {
-		$ret = self::p($sql);
-
-		if (is_bool($ret)) {
-			return $ret;
-		}
-
-		$columns = self::columnCount($ret);
-
-		$data = self::inArray($ret);
-
-		if ((count($data) == 0) && ($columns == 0)) {
-			return true;
+	public static function escape($str) {
+		switch (self::$driver) {
+			case 'pdo':
+				return substr(@self::$db->quote($str, PDO::PARAM_STR), 1, -1);
+			case 'mysqli':
+				return @self::$db->real_escape_string($str);
 		}
-
-		return $data;
 	}
 
-	public function dbg($dbg) {
-		$this->debug = $dbg;
-	}
-
-	public function escape($str) {
-		if ($this->db && $this->connected) {
-			switch ($this->driver) {
-				case 'pdo':
-					return substr(@$this->db->quote($str, PDO::PARAM_STR), 1, -1);
-				case 'mysqli':
-					return @$this->db->real_escape_string($str);
-				case 'mysql':
-					return @mysql_real_escape_string($str,$this->db);
-			}
-		}
-	}
+	public static function connected() {
+		$connected = false;
 
-	function connected() {
-		switch ($this->driver) {
+		switch (self::$driver) {
 			case 'pdo':
-				// Not sure if this really is working like expected
-				$connected = ($this->db->getAttribute(PDO::ATTR_CONNECTION_STATUS) != "");
+				$r = dba::p("SELECT 1");
+				if (DBM::is_result($r)) {
+					$row = dba::inArray($r);
+					$connected = ($row[0]['1'] == '1');
+				}
 				break;
 			case 'mysqli':
-				$connected = $this->db->ping();
-				break;
-			case 'mysql':
-				$connected = mysql_ping($this->db);
+				$connected = self::$db->ping();
 				break;
 		}
 		return $connected;
 	}
 
-	function __destruct() {
-		if ($this->db) {
-			switch ($this->driver) {
-				case 'pdo':
-					$this->db = null;
-					break;
-				case 'mysqli':
-					$this->db->close();
-					break;
-				case 'mysql':
-					mysql_close($this->db);
-					break;
-			}
-		}
-	}
-
 	/**
 	 * @brief Replaces ANY_VALUE() function by MIN() function,
 	 *  if the database server does not support ANY_VALUE().
@@ -292,8 +233,8 @@ class dba {
 	 * @param string $sql An SQL string without the values
 	 * @return string The input SQL string modified if necessary.
 	 */
-	public function any_value_fallback($sql) {
-		$server_info = $this->server_info();
+	public static function any_value_fallback($sql) {
+		$server_info = self::server_info();
 		if (version_compare($server_info, '5.7.5', '<') ||
 			(stripos($server_info, 'MariaDB') !== false)) {
 			$sql = str_ireplace('ANY_VALUE(', 'MIN(', $sql);
@@ -310,7 +251,7 @@ class dba {
 	 * @param string $sql An SQL string without the values
 	 * @return string The input SQL string modified if necessary.
 	 */
-	public function clean_query($sql) {
+	public static function clean_query($sql) {
 		$search = array("\t", "\n", "\r", "  ");
 		$replace = array(' ', ' ', ' ', ' ');
 		do {
@@ -335,7 +276,7 @@ class dba {
 			if (is_int($args[$param]) || is_float($args[$param])) {
 				$replace = intval($args[$param]);
 			} else {
-				$replace = "'".self::$dbo->escape($args[$param])."'";
+				$replace = "'".self::escape($args[$param])."'";
 			}
 
 			$pos = strpos($sql, '?', $offset);
@@ -366,6 +307,10 @@ class dba {
 	/**
 	 * @brief Executes a prepared statement that returns data
 	 * @usage Example: $r = p("SELECT * FROM `item` WHERE `guid` = ?", $guid);
+	 *
+	 * Please only use it with complicated queries.
+	 * For all regular queries please use dba::select or dba::exists
+	 *
 	 * @param string $sql SQL statement
 	 * @return object statement object
 	 */
@@ -387,7 +332,7 @@ class dba {
 			$args[++$i] = $param;
 		}
 
-		if (!self::$dbo || !self::$dbo->connected) {
+		if (!self::$connected) {
 			return false;
 		}
 
@@ -396,8 +341,8 @@ class dba {
 			logger('Parameter mismatch. Query "'.$sql.'" - Parameters '.print_r($args, true), LOGGER_DEBUG);
 		}
 
-		$sql = self::$dbo->clean_query($sql);
-		$sql = self::$dbo->any_value_fallback($sql);
+		$sql = self::clean_query($sql);
+		$sql = self::any_value_fallback($sql);
 
 		$orig_sql = $sql;
 
@@ -405,9 +350,9 @@ class dba {
 			$sql = "/*".System::callstack()." */ ".$sql;
 		}
 
-		self::$dbo->error = '';
-		self::$dbo->errorno = 0;
-		self::$dbo->affected_rows = 0;
+		self::$error = '';
+		self::$errorno = 0;
+		self::$affected_rows = 0;
 
 		// We have to make some things different if this function is called from "e"
 		$trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
@@ -421,25 +366,25 @@ class dba {
 		// We are having an own error logging in the function "e"
 		$called_from_e = ($called_from['function'] == 'e');
 
-		switch (self::$dbo->driver) {
+		switch (self::$driver) {
 			case 'pdo':
 				// If there are no arguments we use "query"
 				if (count($args) == 0) {
-					if (!$retval = self::$dbo->db->query($sql)) {
-						$errorInfo = self::$dbo->db->errorInfo();
-						self::$dbo->error = $errorInfo[2];
-						self::$dbo->errorno = $errorInfo[1];
+					if (!$retval = self::$db->query($sql)) {
+						$errorInfo = self::$db->errorInfo();
+						self::$error = $errorInfo[2];
+						self::$errorno = $errorInfo[1];
 						$retval = false;
 						break;
 					}
-					self::$dbo->affected_rows = $retval->rowCount();
+					self::$affected_rows = $retval->rowCount();
 					break;
 				}
 
-				if (!$stmt = self::$dbo->db->prepare($sql)) {
-					$errorInfo = self::$dbo->db->errorInfo();
-					self::$dbo->error = $errorInfo[2];
-					self::$dbo->errorno = $errorInfo[1];
+				if (!$stmt = self::$db->prepare($sql)) {
+					$errorInfo = self::$db->errorInfo();
+					self::$error = $errorInfo[2];
+					self::$errorno = $errorInfo[1];
 					$retval = false;
 					break;
 				}
@@ -450,12 +395,12 @@ class dba {
 
 				if (!$stmt->execute()) {
 					$errorInfo = $stmt->errorInfo();
-					self::$dbo->error = $errorInfo[2];
-					self::$dbo->errorno = $errorInfo[1];
+					self::$error = $errorInfo[2];
+					self::$errorno = $errorInfo[1];
 					$retval = false;
 				} else {
 					$retval = $stmt;
-					self::$dbo->affected_rows = $retval->rowCount();
+					self::$affected_rows = $retval->rowCount();
 				}
 				break;
 			case 'mysqli':
@@ -466,26 +411,26 @@ class dba {
 
 				// The fallback routine is called as well when there are no arguments
 				if (!$can_be_prepared || (count($args) == 0)) {
-					$retval = self::$dbo->db->query(self::replace_parameters($sql, $args));
-					if (self::$dbo->db->errno) {
-						self::$dbo->error = self::$dbo->db->error;
-						self::$dbo->errorno = self::$dbo->db->errno;
+					$retval = self::$db->query(self::replace_parameters($sql, $args));
+					if (self::$db->errno) {
+						self::$error = self::$db->error;
+						self::$errorno = self::$db->errno;
 						$retval = false;
 					} else {
 						if (isset($retval->num_rows)) {
-							self::$dbo->affected_rows = $retval->num_rows;
+							self::$affected_rows = $retval->num_rows;
 						} else {
-							self::$dbo->affected_rows = self::$dbo->db->affected_rows;
+							self::$affected_rows = self::$db->affected_rows;
 						}
 					}
 					break;
 				}
 
-				$stmt = self::$dbo->db->stmt_init();
+				$stmt = self::$db->stmt_init();
 
 				if (!$stmt->prepare($sql)) {
-					self::$dbo->error = $stmt->error;
-					self::$dbo->errorno = $stmt->errno;
+					self::$error = $stmt->error;
+					self::$errorno = $stmt->errno;
 					$retval = false;
 					break;
 				}
@@ -511,44 +456,28 @@ class dba {
 				}
 
 				if (!$stmt->execute()) {
-					self::$dbo->error = self::$dbo->db->error;
-					self::$dbo->errorno = self::$dbo->db->errno;
+					self::$error = self::$db->error;
+					self::$errorno = self::$db->errno;
 					$retval = false;
 				} else {
 					$stmt->store_result();
 					$retval = $stmt;
-					self::$dbo->affected_rows = $retval->affected_rows;
-				}
-				break;
-			case 'mysql':
-				// For the old "mysql" functions we cannot use prepared statements
-				$retval = mysql_query(self::replace_parameters($sql, $args), self::$dbo->db);
-				if (mysql_errno(self::$dbo->db)) {
-					self::$dbo->error = mysql_error(self::$dbo->db);
-					self::$dbo->errorno = mysql_errno(self::$dbo->db);
-				} else {
-					self::$dbo->affected_rows = mysql_affected_rows($retval);
-
-					// Due to missing mysql_* support this here wasn't tested at all
-					// See here: http://php.net/manual/en/function.mysql-num-rows.php
-					if (self::$dbo->affected_rows <= 0) {
-						self::$dbo->affected_rows = mysql_num_rows($retval);
-					}
+					self::$affected_rows = $retval->affected_rows;
 				}
 				break;
 		}
 
 		// We are having an own error logging in the function "e"
-		if ((self::$dbo->errorno != 0) && !$called_from_e) {
+		if ((self::$errorno != 0) && !$called_from_e) {
 			// We have to preserve the error code, somewhere in the logging it get lost
-			$error = self::$dbo->error;
-			$errorno = self::$dbo->errorno;
+			$error = self::$error;
+			$errorno = self::$errorno;
 
-			logger('DB Error '.self::$dbo->errorno.': '.self::$dbo->error."\n".
+			logger('DB Error '.self::$errorno.': '.self::$error."\n".
 				System::callstack(8)."\n".self::replace_parameters($sql, $params));
 
-			self::$dbo->error = $error;
-			self::$dbo->errorno = $errorno;
+			self::$error = $error;
+			self::$errorno = $errorno;
 		}
 
 		$a->save_timestamp($stamp1, 'database');
@@ -574,6 +503,8 @@ class dba {
 	/**
 	 * @brief Executes a prepared statement like UPDATE or INSERT that doesn't return data
 	 *
+	 * Please use dba::delete, dba::insert, dba::update, ... instead
+	 *
 	 * @param string $sql SQL statement
 	 * @return boolean Was the query successfull? False is returned only if an error occurred
 	 */
@@ -600,18 +531,18 @@ class dba {
 
 			self::close($stmt);
 
-		} while ((self::$dbo->errorno == 1213) && (--$timeout > 0));
+		} while ((self::$errorno == 1213) && (--$timeout > 0));
 
-		if (self::$dbo->errorno != 0) {
+		if (self::$errorno != 0) {
 			// We have to preserve the error code, somewhere in the logging it get lost
-			$error = self::$dbo->error;
-			$errorno = self::$dbo->errorno;
+			$error = self::$error;
+			$errorno = self::$errorno;
 
-			logger('DB Error '.self::$dbo->errorno.': '.self::$dbo->error."\n".
+			logger('DB Error '.self::$errorno.': '.self::$error."\n".
 				System::callstack(8)."\n".self::replace_parameters($sql, $params));
 
-			self::$dbo->error = $error;
-			self::$dbo->errorno = $errorno;
+			self::$error = $error;
+			self::$errorno = $errorno;
 		}
 
 		$a->save_timestamp($stamp, "database_write");
@@ -656,6 +587,8 @@ class dba {
 	/**
 	 * @brief Fetches the first row
 	 *
+	 * Please use dba::select or dba::exists whenever this is possible.
+	 *
 	 * @param string $sql SQL statement
 	 * @return array first row of query
 	 */
@@ -681,7 +614,7 @@ class dba {
 	 * @return int Number of rows
 	 */
 	public static function affected_rows() {
-		return self::$dbo->affected_rows;
+		return self::$affected_rows;
 	}
 
 	/**
@@ -694,13 +627,11 @@ class dba {
 		if (!is_object($stmt)) {
 			return 0;
 		}
-		switch (self::$dbo->driver) {
+		switch (self::$driver) {
 			case 'pdo':
 				return $stmt->columnCount();
 			case 'mysqli':
 				return $stmt->field_count;
-			case 'mysql':
-				return mysql_affected_rows($stmt);
 		}
 		return 0;
 	}
@@ -714,13 +645,11 @@ class dba {
 		if (!is_object($stmt)) {
 			return 0;
 		}
-		switch (self::$dbo->driver) {
+		switch (self::$driver) {
 			case 'pdo':
 				return $stmt->rowCount();
 			case 'mysqli':
 				return $stmt->num_rows;
-			case 'mysql':
-				return mysql_num_rows($stmt);
 		}
 		return 0;
 	}
@@ -736,7 +665,7 @@ class dba {
 			return false;
 		}
 
-		switch (self::$dbo->driver) {
+		switch (self::$driver) {
 			case 'pdo':
 				return $stmt->fetch(PDO::FETCH_ASSOC);
 			case 'mysqli':
@@ -771,8 +700,6 @@ class dba {
 					$columns[$fields[$param]->name] = $col;
 				}
 				return $columns;
-			case 'mysql':
-				return mysql_fetch_array(self::$dbo->result, MYSQL_ASSOC);
 		}
 	}
 
@@ -786,7 +713,13 @@ class dba {
 	 * @return boolean was the insert successfull?
 	 */
 	public static function insert($table, $param, $on_duplicate_update = false) {
-		$sql = "INSERT INTO `".self::$dbo->escape($table)."` (`".implode("`, `", array_keys($param))."`) VALUES (".
+
+		if (empty($table) || empty($param)) {
+			logger('Table and fields have to be set');
+			return false;
+		}
+
+		$sql = "INSERT INTO `".self::escape($table)."` (`".implode("`, `", array_keys($param))."`) VALUES (".
 			substr(str_repeat("?, ", count($param)), 0, -2).")";
 
 		if ($on_duplicate_update) {
@@ -805,15 +738,12 @@ class dba {
 	 * @return integer Last inserted id
 	 */
 	public static function lastInsertId() {
-		switch (self::$dbo->driver) {
+		switch (self::$driver) {
 			case 'pdo':
-				$id = self::$dbo->db->lastInsertId();
+				$id = self::$db->lastInsertId();
 				break;
 			case 'mysqli':
-				$id = self::$dbo->db->insert_id;
-				break;
-			case 'mysql':
-				$id = mysql_insert_id(self::$dbo);
+				$id = self::$db->insert_id;
 				break;
 		}
 		return $id;
@@ -831,7 +761,7 @@ class dba {
 	public static function lock($table) {
 		// See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
 		self::e("SET autocommit=0");
-		$success = self::e("LOCK TABLES `".self::$dbo->escape($table)."` WRITE");
+		$success = self::e("LOCK TABLES `".self::escape($table)."` WRITE");
 		if (!$success) {
 			self::e("SET autocommit=1");
 		} else {
@@ -929,6 +859,11 @@ class dba {
 	 */
 	public static function delete($table, $param, $in_process = false, &$callstack = array()) {
 
+		if (empty($table) || empty($param)) {
+			logger('Table and condition have to be set');
+			return false;
+		}
+
 		$commands = array();
 
 		// Create a key for the loop prevention
@@ -941,7 +876,7 @@ class dba {
 
 		$callstack[$key] = true;
 
-		$table = self::$dbo->escape($table);
+		$table = self::escape($table);
 
 		$commands[$key] = array('table' => $table, 'param' => $param);
 
@@ -1092,18 +1027,19 @@ class dba {
 	 */
 	public static function update($table, $fields, $condition, $old_fields = array()) {
 
-		$table = self::$dbo->escape($table);
+		if (empty($table) || empty($fields) || empty($condition)) {
+			logger('Table, fields and condition have to be set');
+			return false;
+		}
 
-		if (count($condition) > 0) {
-			$array_element = each($condition);
-			$array_key = $array_element['key'];
-			if (is_int($array_key)) {
-				$condition_string = " WHERE ".array_shift($condition);
-			} else {
-				$condition_string = " WHERE `".implode("` = ? AND `", array_keys($condition))."` = ?";
-			}
+		$table = self::escape($table);
+
+		$array_element = each($condition);
+		$array_key = $array_element['key'];
+		if (is_int($array_key)) {
+			$condition_string = " WHERE ".array_shift($condition);
 		} else {
-			$condition_string = "";
+			$condition_string = " WHERE `".implode("` = ? AND `", array_keys($condition))."` = ?";
 		}
 
 		if (is_bool($old_fields)) {
@@ -1159,12 +1095,17 @@ class dba {
 	 * Example:
 	 * $table = "item";
 	 * $fields = array("id", "uri", "uid", "network");
+	 *
 	 * $condition = array("uid" => 1, "network" => 'dspr');
+	 * or:
+	 * $condition = array("`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr');
+	 *
 	 * $params = array("order" => array("id", "received" => true), "limit" => 1);
 	 *
 	 * $data = dba::select($table, $fields, $condition, $params);
 	 */
-	public static function select($table, $fields = array(), $condition = array(), $params = array()) {
+	public static function select($table, array $fields = [], array $condition = [], array $params = [])
+	{
 		if ($table == '') {
 			return false;
 		}
@@ -1175,17 +1116,7 @@ class dba {
 			$select_fields = "*";
 		}
 
-		if (count($condition) > 0) {
-			$array_element = each($condition);
-			$array_key = $array_element['key'];
-			if (is_int($array_key)) {
-				$condition_string = " WHERE ".array_shift($condition);
-			} else {
-				$condition_string = " WHERE `".implode("` = ? AND `", array_keys($condition))."` = ?";
-			}
-		} else {
-			$condition_string = "";
-		}
+		$condition_string = self::buildCondition($condition);
 
 		$param_string = '';
 		$single_row = false;
@@ -1207,6 +1138,11 @@ class dba {
 			$single_row = ($params['limit'] == 1);
 		}
 
+		if (isset($params['limit']) && is_array($params['limit'])) {
+			$param_string .= " LIMIT ".intval($params['limit'][0]).", ".intval($params['limit'][1]);
+			$single_row = ($params['limit'][1] == 1);
+		}
+
 		if (isset($params['only_query']) && $params['only_query']) {
 			$single_row = !$params['only_query'];
 		}
@@ -1224,6 +1160,71 @@ class dba {
 		}
 	}
 
+	/**
+	 * @brief Counts the rows from a table satisfying the provided condition
+	 *
+	 * @param string $table Table name
+	 * @param array $condition array of fields for condition
+	 *
+	 * @return int
+	 *
+	 * Example:
+	 * $table = "item";
+	 *
+	 * $condition = ["uid" => 1, "network" => 'dspr'];
+	 * or:
+	 * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
+	 *
+	 * $count = dba::count($table, $condition);
+	 */
+	public static function count($table, array $condition = [])
+	{
+		if ($table == '') {
+			return false;
+		}
+
+		$condition_string = self::buildCondition($condition);
+
+		$sql = "SELECT COUNT(*) AS `count` FROM `".$table."`".$condition_string;
+
+		$row = self::fetch_first($sql, $condition);
+
+		return $row['count'];
+	}
+
+	/**
+	 * @brief Returns the SQL condition string built from the provided condition array
+	 *
+	 * This function operates with two modes.
+	 * - Supplied with a filed/value associative array, it builds simple strict
+	 *   equality conditions linked by AND.
+	 * - Supplied with a flat list, the first element is the condition string and
+	 *   the following arguments are the values to be interpolated
+	 *
+	 * $condition = ["uid" => 1, "network" => 'dspr'];
+	 * or:
+	 * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
+	 *
+	 * In either case, the provided array is left with the parameters only
+	 *
+	 * @param array $condition
+	 * @return string
+	 */
+	private static function buildCondition(array &$condition = [])
+	{
+		$condition_string = '';
+		if (count($condition) > 0) {
+			$array_element = each($condition);
+			$array_key = $array_element['key'];
+			if (is_int($array_key)) {
+				$condition_string = " WHERE ".array_shift($condition);
+			} else {
+				$condition_string = " WHERE `".implode("` = ? AND `", array_keys($condition))."` = ?";
+			}
+		}
+
+		return $condition_string;
+	}
 
 	/**
 	 * @brief Fills an array with data from a query
@@ -1246,6 +1247,24 @@ class dba {
 		return $data;
 	}
 
+	/**
+	 * @brief Returns the error number of the last query
+	 *
+	 * @return string Error number (0 if no error)
+	 */
+	public static function errorNo() {
+		return self::$errorno;
+	}
+
+	/**
+	 * @brief Returns the error message of the last query
+	 *
+	 * @return string Error message ('' if no error)
+	 */
+	public static function errorMessage() {
+		return self::$error;
+	}
+
 	/**
 	 * @brief Closes the current statement
 	 *
@@ -1257,62 +1276,44 @@ class dba {
 			return false;
 		}
 
-		switch (self::$dbo->driver) {
+		switch (self::$driver) {
 			case 'pdo':
 				return $stmt->closeCursor();
 			case 'mysqli':
-				return $stmt->free_result();
+				$stmt->free_result();
 				return $stmt->close();
-			case 'mysql':
-				return mysql_free_result($stmt);
 		}
 	}
 }
 
-function printable($s) {
-	$s = preg_replace("~([\x01-\x08\x0E-\x0F\x10-\x1F\x7F-\xFF])~",".", $s);
-	$s = str_replace("\x00",'.',$s);
-	if (x($_SERVER,'SERVER_NAME')) {
-		$s = escape_tags($s);
-	}
-	return $s;
-}
-
-// Procedural functions
-function dbg($state) {
-	global $db;
-
-	if ($db) {
-		$db->dbg($state);
-	}
-}
-
 function dbesc($str) {
-	global $db;
-
-	if ($db && $db->connected) {
-		return($db->escape($str));
+	if (dba::$connected) {
+		return(dba::escape($str));
 	} else {
 		return(str_replace("'","\\'",$str));
 	}
 }
 
-// Function: q($sql,$args);
-// Description: execute SQL query with printf style args.
-// Example: $r = q("SELECT * FROM `%s` WHERE `uid` = %d",
-//                   'user', 1);
+/**
+ * @brief execute SQL query with printf style args - deprecated
+ *
+ * Please use the dba:: functions instead:
+ * dba::select, dba::exists, dba::insert
+ * dba::delete, dba::update, dba::p, dba::e
+ *
+ * @param $args Query parameters (1 to N parameters of different types)
+ * @return array Query array
+ */
 function q($sql) {
-	global $db;
-
 	$args = func_get_args();
 	unset($args[0]);
 
-	if (!$db || !$db->connected) {
+	if (!dba::$connected) {
 		return false;
 	}
 
-	$sql = $db->clean_query($sql);
-	$sql = $db->any_value_fallback($sql);
+	$sql = dba::clean_query($sql);
+	$sql = dba::any_value_fallback($sql);
 
 	$stmt = @vsprintf($sql, $args);
 
@@ -1333,77 +1334,6 @@ function q($sql) {
 	return $data;
 }
 
-/**
- * @brief Performs a query with "dirty reads" - deprecated
- *
- * By doing dirty reads (reading uncommitted data) no locks are performed
- * This function can be used to fetch data that doesn't need to be reliable.
- *
- * Hadn't worked like expected and does now the same like the other function.
- *
- * @param $args Query parameters (1 to N parameters of different types)
- * @return array Query array
- */
-function qu($sql) {
-	global $db;
-
-	$args = func_get_args();
-	unset($args[0]);
-
-	if ($db && $db->connected) {
-		$sql = $db->clean_query($sql);
-		$sql = $db->any_value_fallback($sql);
-		$stmt = @vsprintf($sql,$args); // Disabled warnings
-		if ($stmt === false)
-			logger('dba: vsprintf error: ' . print_r(debug_backtrace(),true), LOGGER_DEBUG);
-
-		$db->log_index($stmt);
-
-		$retval = $db->q($stmt);
-		return $retval;
-	}
-
-	/**
-	 *
-	 * This will happen occasionally trying to store the
-	 * session data after abnormal program termination
-	 *
-	 */
-	logger('dba: no database: ' . print_r($args,true));
-	return false;
-}
-
-/**
- *
- * Raw db query, no arguments
- *
- */
-function dbq($sql) {
-	global $db;
-
-	if ($db && $db->connected) {
-		$ret = $db->q($sql);
-	} else {
-		$ret = false;
-	}
-	return $ret;
-}
-
-// Caller is responsible for ensuring that any integer arguments to
-// dbesc_array are actually integers and not malformed strings containing
-// SQL injection vectors. All integer array elements should be specifically
-// cast to int to avoid trouble.
-function dbesc_array_cb(&$item, $key) {
-	if (is_string($item))
-		$item = dbesc($item);
-}
-
-function dbesc_array(&$arr) {
-	if (is_array($arr) && count($arr)) {
-		array_walk($arr,'dbesc_array_cb');
-	}
-}
-
 function dba_timer() {
 	return microtime(true);
 }