]> git.mxchange.org Git - friendica.git/blobdiff - include/dba.php
Replace dba::select(limit => 1) by dba::selectOne
[friendica.git] / include / dba.php
index fa33f245aeb0210c3a23030f16c4f3d72e3ceaf1..3a72d596491741a6b3928ffbfb1c7fe74d488780 100644 (file)
@@ -1,36 +1,33 @@
 <?php
-use \Friendica\Core\System;
+use Friendica\Core\System;
+use Friendica\Database\DBM;
+use Friendica\Database\DBStructure;
 
-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 +47,24 @@ 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 +75,35 @@ 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()) {
-                               $this->connected = true;
+                               self::$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)) {
-                               $this->connected = true;
-
-                               if (isset($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();
+                               System::unavailable();
                        }
                }
                $a->save_timestamp($stamp1, "network");
 
-               self::$dbo = $this;
+               return true;
        }
 
        /**
@@ -129,21 +114,18 @@ 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 +133,10 @@ 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 +144,7 @@ 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 +161,15 @@ 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"])));
@@ -214,83 +196,33 @@ class dba {
                }
        }
 
-       /**
-        * @brief execute SQL query - deprecated
-        *
-        * Please use the dba:: functions instead:
-        * dba::select, dba::exists, dba::insert
-        * dba::delete, dba::update, dba::p, dba::e
-        *
-        * @param string $sql SQL query
-        * @return array Query array
-        */
-       public function q($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 static function connected() {
+               $connected = false;
 
-       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);
-                       }
-               }
-       }
-
-       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().
@@ -302,8 +234,8 @@ 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);
@@ -320,7 +252,7 @@ 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", "  ");
                $replace = array(' ', ' ', ' ', ' ');
                do {
@@ -345,7 +277,7 @@ class dba {
                        if (is_int($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);
@@ -401,7 +333,7 @@ class dba {
                        $args[++$i] = $param;
                }
 
-               if (!self::$dbo || !self::$dbo->connected) {
+               if (!self::$connected) {
                        return false;
                }
 
@@ -410,8 +342,8 @@ 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;
 
@@ -419,9 +351,9 @@ 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);
@@ -435,25 +367,25 @@ 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;
                                }
@@ -464,12 +396,12 @@ 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':
@@ -480,26 +412,26 @@ 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;
                                }
@@ -525,44 +457,28 @@ 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');
@@ -616,18 +532,18 @@ 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");
@@ -656,7 +572,7 @@ class dba {
                        $fields = array($array_key);
                }
 
-               $stmt = self::select($table, $fields, $condition, array('limit' => 1, 'only_query' => true));
+               $stmt = self::select($table, $fields, $condition, ['limit' => 1]);
 
                if (is_bool($stmt)) {
                        $retval = $stmt;
@@ -699,7 +615,7 @@ class dba {
         * @return int Number of rows
         */
        public static function affected_rows() {
-               return self::$dbo->affected_rows;
+               return self::$affected_rows;
        }
 
        /**
@@ -712,13 +628,11 @@ 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;
        }
@@ -732,13 +646,11 @@ 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;
        }
@@ -754,7 +666,7 @@ class dba {
                        return false;
                }
 
-               switch (self::$dbo->driver) {
+               switch (self::$driver) {
                        case 'pdo':
                                return $stmt->fetch(PDO::FETCH_ASSOC);
                        case 'mysqli':
@@ -789,8 +701,6 @@ class dba {
                                        $columns[$fields[$param]->name] = $col;
                                }
                                return $columns;
-                       case 'mysql':
-                               return mysql_fetch_array(self::$dbo->result, MYSQL_ASSOC);
                }
        }
 
@@ -804,7 +714,13 @@ 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 ($on_duplicate_update) {
@@ -823,15 +739,12 @@ class dba {
         * @return integer Last inserted id
         */
        public static function lastInsertId() {
-               switch (self::$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 $id;
@@ -849,7 +762,7 @@ class dba {
        public static function lock($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 {
@@ -917,12 +830,12 @@ class dba {
        /**
         * @brief Build the array with the table relations
         *
-        * The array is build from the database definitions in dbstructure.php
+        * The array is build from the database definitions in DBStructure.php
         *
         * This process must only be started once, since the value is cached.
         */
        private static function build_relation_data() {
-               $definition = db_definition();
+               $definition = DBStructure::definition();
 
                foreach ($definition AS $table => $structure) {
                        foreach ($structure['fields'] AS $field => $field_struct) {
@@ -947,6 +860,11 @@ class dba {
         */
        public static function delete($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
@@ -959,7 +877,7 @@ class dba {
 
                $callstack[$key] = true;
 
-               $table = self::$dbo->escape($table);
+               $table = self::escape($table);
 
                $commands[$key] = array('table' => $table, 'param' => $param);
 
@@ -1110,24 +1028,25 @@ 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)) {
                        $do_insert = $old_fields;
 
-                       $old_fields = self::select($table, array(), $condition, array('limit' => 1));
+                       $old_fields = self::selectOne($table, [], $condition);
 
                        if (is_bool($old_fields)) {
                                if ($do_insert) {
@@ -1164,6 +1083,31 @@ class dba {
                return self::e($sql, $params);
        }
 
+       /**
+        * Retrieve a single record from a table and returns it in an associative array
+        * 
+        * @brief Retrieve a single record from a table
+        * @param string $table
+        * @param array  $fields
+        * @param array  $condition
+        * @param array  $params
+        * @return bool|array
+        * @see dba::select
+        */
+       public static function selectOne($table, array $fields = [], array $condition = [], $params = [])
+       {
+               $params['limit'] = 1;
+               $result = self::select($table, $fields, $condition, $params);
+
+               if (is_bool($result)) {
+                       return $result;
+               } else {
+                       $row = self::fetch($result);
+                       self::close($result);
+                       return $row;
+               }
+       }
+
        /**
         * @brief Select rows from a table
         *
@@ -1186,66 +1130,112 @@ class dba {
         *
         * $data = dba::select($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;
                }
 
                if (count($fields) > 0) {
-                       $select_fields = "`".implode("`, `", array_values($fields))."`";
+                       $select_fields = "`" . implode("`, `", array_values($fields)) . "`";
                } else {
                        $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 = "";
-               }
-
-               $param_string = '';
-               $single_row = false;
+               $condition_string = self::buildCondition($condition);
 
                if (isset($params['order'])) {
-                       $param_string .= " ORDER BY ";
+                       $order_string = " ORDER BY ";
                        foreach ($params['order'] AS $fields => $order) {
                                if (!is_int($fields)) {
-                                       $param_string .= "`".$fields."` ".($order ? "DESC" : "ASC").", ";
+                                       $order_string .= "`" . $fields . "` " . ($order ? "DESC" : "ASC") . ", ";
                                } else {
-                                       $param_string .= "`".$order."`, ";
+                                       $order_string .= "`" . $order . "`, ";
                                }
                        }
-                       $param_string = substr($param_string, 0, -2);
+                       $order_string = substr($order_string, 0, -2);
                }
 
                if (isset($params['limit']) && is_int($params['limit'])) {
-                       $param_string .= " LIMIT ".$params['limit'];
-                       $single_row = ($params['limit'] == 1);
+                       $limit_string = " LIMIT " . $params['limit'];
                }
 
-               if (isset($params['only_query']) && $params['only_query']) {
-                       $single_row = !$params['only_query'];
+               if (isset($params['limit']) && is_array($params['limit'])) {
+                       $limit_string = " LIMIT " . intval($params['limit'][0]) . ", " . intval($params['limit'][1]);
                }
 
-               $sql = "SELECT ".$select_fields." FROM `".$table."`".$condition_string.$param_string;
+               $sql = "SELECT " . $select_fields . " FROM `" . $table . "`" . $condition_string . $order_string . $limit_string;
 
                $result = self::p($sql, $condition);
 
-               if (is_bool($result) || !$single_row) {
-                       return $result;
-               } else {
-                       $row = self::fetch($result);
-                       self::close($result);
-                       return $row;
+               return $result;
+       }
+
+       /**
+        * @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
@@ -1268,6 +1258,24 @@ 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
         *
@@ -1279,41 +1287,19 @@ 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));
        }
@@ -1327,20 +1313,18 @@ function dbesc($str) {
  * dba::delete, dba::update, dba::p, dba::e
  *
  * @param $args Query parameters (1 to N parameters of different types)
- * @return array Query array
+ * @return array|bool Query array
  */
 function q($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);
 
@@ -1361,45 +1345,6 @@ function q($sql) {
        return $data;
 }
 
-/**
- * @brief Performs a query with "dirty reads" - deprecated
- *
- * Please use the dba:: functions instead:
- * dba::select, dba::exists, dba::insert
- * dba::delete, dba::update, dba::p, dba::e
- *
- * @param $args Query parameters (1 to N parameters of different types)
- * @return array Query array
- */
-function qu($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;
-}
-
 function dba_timer() {
        return microtime(true);
 }