src/Database/DBA.php

   1 <?php
   2
   3 namespace Friendica\Database;
   4
   5 // Do not use Core\Config in this class at risk of infinite loop.
   6 // Please use App->getConfigVariable() instead.
   7 //use Friendica\Core\Config;
   8
   9 use Friendica\Core\System;
  10 use Friendica\Util\DateTimeFormat;
  11 use mysqli;
  12 use mysqli_result;
  13 use mysqli_stmt;
  14 use PDO;
  15 use PDOException;
  16 use PDOStatement;
  17
  18 require_once 'include/dba.php';
  19
  20 /**
  21  * @class MySQL database class
  22  *
  23  * This class is for the low level database stuff that does driver specific things.
  24  */
  25 class DBA
  26 {
  27         /**
  28          * Lowest possible date value
  29          */
  30         const NULL_DATE     = '0001-01-01';
  31         /**
  32          * Lowest possible datetime value
  33          */
  34         const NULL_DATETIME = '0001-01-01 00:00:00';
  35
  36         public static $connected = false;
  37
  38         private static $server_info = '';
  39         private static $connection;
  40         private static $driver;
  41         private static $error = false;
  42         private static $errorno = 0;
  43         private static $affected_rows = 0;
  44         private static $in_transaction = false;
  45         private static $in_retrial = false;
  46         private static $relation = [];
  47         private static $db_serveraddr = '';
  48         private static $db_user = '';
  49         private static $db_pass = '';
  50         private static $db_name = '';
  51         private static $db_charset = '';
  52
  53         public static function connect($serveraddr, $user, $pass, $db, $charset = null)
  54         {
  55                 if (!is_null(self::$connection) && self::connected()) {
  56                         return true;
  57                 }
  58
  59                 // We are storing these values for being able to perform a reconnect
  60                 self::$db_serveraddr = $serveraddr;
  61                 self::$db_user = $user;
  62                 self::$db_pass = $pass;
  63                 self::$db_name = $db;
  64                 self::$db_charset = $charset;
  65
  66                 $port = 0;
  67                 $serveraddr = trim($serveraddr);
  68
  69                 $serverdata = explode(':', $serveraddr);
  70                 $server = $serverdata[0];
  71
  72                 if (count($serverdata) > 1) {
  73                         $port = trim($serverdata[1]);
  74                 }
  75
  76                 $server = trim($server);
  77                 $user = trim($user);
  78                 $pass = trim($pass);
  79                 $db = trim($db);
  80                 $charset = trim($charset);
  81
  82                 if (!(strlen($server) && strlen($user))) {
  83                         return false;
  84                 }
  85
  86                 if (class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
  87                         self::$driver = 'pdo';
  88                         $connect = "mysql:host=".$server.";dbname=".$db;
  89
  90                         if ($port > 0) {
  91                                 $connect .= ";port=".$port;
  92                         }
  93
  94                         if ($charset) {
  95                                 $connect .= ";charset=".$charset;
  96                         }
  97
  98                         try {
  99                                 self::$connection = @new PDO($connect, $user, $pass);
 100                                 self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
 101                                 self::$connected = true;
 102                         } catch (PDOException $e) {
 103                                 /// @TODO At least log exception, don't ignore it!
 104                         }
 105                 }
 106
 107                 if (!self::$connected && class_exists('\mysqli')) {
 108                         self::$driver = 'mysqli';
 109
 110                         if ($port > 0) {
 111                                 self::$connection = @new mysqli($server, $user, $pass, $db, $port);
 112                         } else {
 113                                 self::$connection = @new mysqli($server, $user, $pass, $db);
 114                         }
 115
 116                         if (!mysqli_connect_errno()) {
 117                                 self::$connected = true;
 118
 119                                 if ($charset) {
 120                                         self::$connection->set_charset($charset);
 121                                 }
 122                         }
 123                 }
 124
 125                 // No suitable SQL driver was found.
 126                 if (!self::$connected) {
 127                         self::$driver = null;
 128                         self::$connection = null;
 129                 }
 130
 131                 return self::$connected;
 132         }
 133
 134         /**
 135          * Disconnects the current database connection
 136          */
 137         public static function disconnect()
 138         {
 139                 if (is_null(self::$connection)) {
 140                         return;
 141                 }
 142
 143                 switch (self::$driver) {
 144                         case 'pdo':
 145                                 self::$connection = null;
 146                                 break;
 147                         case 'mysqli':
 148                                 self::$connection->close();
 149                                 self::$connection = null;
 150                                 break;
 151                 }
 152         }
 153
 154         /**
 155          * Perform a reconnect of an existing database connection
 156          */
 157         public static function reconnect() {
 158                 self::disconnect();
 159
 160                 $ret = self::connect(self::$db_serveraddr, self::$db_user, self::$db_pass, self::$db_name, self::$db_charset);
 161                 return $ret;
 162         }
 163
 164         /**
 165          * Return the database object.
 166          * @return PDO|mysqli
 167          */
 168         public static function getConnection()
 169         {
 170                 return self::$connection;
 171         }
 172
 173         /**
 174          * @brief Returns the MySQL server version string
 175          *
 176          * This function discriminate between the deprecated mysql API and the current
 177          * object-oriented mysqli API. Example of returned string: 5.5.46-0+deb8u1
 178          *
 179          * @return string
 180          */
 181         public static function serverInfo() {
 182                 if (self::$server_info == '') {
 183                         switch (self::$driver) {
 184                                 case 'pdo':
 185                                         self::$server_info = self::$connection->getAttribute(PDO::ATTR_SERVER_VERSION);
 186                                         break;
 187                                 case 'mysqli':
 188                                         self::$server_info = self::$connection->server_info;
 189                                         break;
 190                         }
 191                 }
 192                 return self::$server_info;
 193         }
 194
 195         /**
 196          * @brief Returns the selected database name
 197          *
 198          * @return string
 199          */
 200         public static function databaseName() {
 201                 $ret = self::p("SELECT DATABASE() AS `db`");
 202                 $data = self::toArray($ret);
 203                 return $data[0]['db'];
 204         }
 205
 206         /**
 207          * @brief Analyze a database query and log this if some conditions are met.
 208          *
 209          * @param string $query The database query that will be analyzed
 210          */
 211         private static function logIndex($query) {
 212                 $a = get_app();
 213
 214                 if (!$a->getConfigVariable('system', 'db_log_index')) {
 215                         return;
 216                 }
 217
 218                 // Don't explain an explain statement
 219                 if (strtolower(substr($query, 0, 7)) == "explain") {
 220                         return;
 221                 }
 222
 223                 // Only do the explain on "select", "update" and "delete"
 224                 if (!in_array(strtolower(substr($query, 0, 6)), ["select", "update", "delete"])) {
 225                         return;
 226                 }
 227
 228                 $r = self::p("EXPLAIN ".$query);
 229                 if (!self::isResult($r)) {
 230                         return;
 231                 }
 232
 233                 $watchlist = explode(',', $a->getConfigVariable('system', 'db_log_index_watch'));
 234                 $blacklist = explode(',', $a->getConfigVariable('system', 'db_log_index_blacklist'));
 235
 236                 while ($row = self::fetch($r)) {
 237                         if ((intval($a->getConfigVariable('system', 'db_loglimit_index')) > 0)) {
 238                                 $log = (in_array($row['key'], $watchlist) &&
 239                                         ($row['rows'] >= intval($a->getConfigVariable('system', 'db_loglimit_index'))));
 240                         } else {
 241                                 $log = false;
 242                         }
 243
 244                         if ((intval($a->getConfigVariable('system', 'db_loglimit_index_high')) > 0) && ($row['rows'] >= intval($a->getConfigVariable('system', 'db_loglimit_index_high')))) {
 245                                 $log = true;
 246                         }
 247
 248                         if (in_array($row['key'], $blacklist) || ($row['key'] == "")) {
 249                                 $log = false;
 250                         }
 251
 252                         if ($log) {
 253                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 254                                 @file_put_contents($a->getConfigVariable('system', 'db_log_index'), DateTimeFormat::utcNow()."\t".
 255                                                 $row['key']."\t".$row['rows']."\t".$row['Extra']."\t".
 256                                                 basename($backtrace[1]["file"])."\t".
 257                                                 $backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
 258                                                 substr($query, 0, 2000)."\n", FILE_APPEND);
 259                         }
 260                 }
 261         }
 262
 263         public static function escape($str) {
 264                 if (self::$connected) {
 265                         switch (self::$driver) {
 266                                 case 'pdo':
 267                                         return substr(@self::$connection->quote($str, PDO::PARAM_STR), 1, -1);
 268
 269                                 case 'mysqli':
 270                                         return @self::$connection->real_escape_string($str);
 271                         }
 272                 } else {
 273                         return str_replace("'", "\\'", $str);
 274                 }
 275         }
 276
 277         public static function connected() {
 278                 $connected = false;
 279
 280                 if (is_null(self::$connection)) {
 281                         return false;
 282                 }
 283
 284                 switch (self::$driver) {
 285                         case 'pdo':
 286                                 $r = self::p("SELECT 1");
 287                                 if (self::isResult($r)) {
 288                                         $row = self::toArray($r);
 289                                         $connected = ($row[0]['1'] == '1');
 290                                 }
 291                                 break;
 292                         case 'mysqli':
 293                                 $connected = self::$connection->ping();
 294                                 break;
 295                 }
 296                 return $connected;
 297         }
 298
 299         /**
 300          * @brief Replaces ANY_VALUE() function by MIN() function,
 301          *  if the database server does not support ANY_VALUE().
 302          *
 303          * Considerations for Standard SQL, or MySQL with ONLY_FULL_GROUP_BY (default since 5.7.5).
 304          * ANY_VALUE() is available from MySQL 5.7.5 https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html
 305          * A standard fall-back is to use MIN().
 306          *
 307          * @param string $sql An SQL string without the values
 308          * @return string The input SQL string modified if necessary.
 309          */
 310         public static function anyValueFallback($sql) {
 311                 $server_info = self::serverInfo();
 312                 if (version_compare($server_info, '5.7.5', '<') ||
 313                         (stripos($server_info, 'MariaDB') !== false)) {
 314                         $sql = str_ireplace('ANY_VALUE(', 'MIN(', $sql);
 315                 }
 316                 return $sql;
 317         }
 318
 319         /**
 320          * @brief beautifies the query - useful for "SHOW PROCESSLIST"
 321          *
 322          * This is safe when we bind the parameters later.
 323          * The parameter values aren't part of the SQL.
 324          *
 325          * @param string $sql An SQL string without the values
 326          * @return string The input SQL string modified if necessary.
 327          */
 328         public static function cleanQuery($sql) {
 329                 $search = ["\t", "\n", "\r", "  "];
 330                 $replace = [' ', ' ', ' ', ' '];
 331                 do {
 332                         $oldsql = $sql;
 333                         $sql = str_replace($search, $replace, $sql);
 334                 } while ($oldsql != $sql);
 335
 336                 return $sql;
 337         }
 338
 339
 340         /**
 341          * @brief Replaces the ? placeholders with the parameters in the $args array
 342          *
 343          * @param string $sql SQL query
 344          * @param array $args The parameters that are to replace the ? placeholders
 345          * @return string The replaced SQL query
 346          */
 347         private static function replaceParameters($sql, $args) {
 348                 $offset = 0;
 349                 foreach ($args AS $param => $value) {
 350                         if (is_int($args[$param]) || is_float($args[$param])) {
 351                                 $replace = intval($args[$param]);
 352                         } else {
 353                                 $replace = "'".self::escape($args[$param])."'";
 354                         }
 355
 356                         $pos = strpos($sql, '?', $offset);
 357                         if ($pos !== false) {
 358                                 $sql = substr_replace($sql, $replace, $pos, 1);
 359                         }
 360                         $offset = $pos + strlen($replace);
 361                 }
 362                 return $sql;
 363         }
 364
 365         /**
 366          * @brief Convert parameter array to an universal form
 367          * @param array $args Parameter array
 368          * @return array universalized parameter array
 369          */
 370         private static function getParam($args) {
 371                 unset($args[0]);
 372
 373                 // When the second function parameter is an array then use this as the parameter array
 374                 if ((count($args) > 0) && (is_array($args[1]))) {
 375                         return $args[1];
 376                 } else {
 377                         return $args;
 378                 }
 379         }
 380
 381         /**
 382          * @brief Executes a prepared statement that returns data
 383          * @usage Example: $r = p("SELECT * FROM `item` WHERE `guid` = ?", $guid);
 384          *
 385          * Please only use it with complicated queries.
 386          * For all regular queries please use DBA::select or DBA::exists
 387          *
 388          * @param string $sql SQL statement
 389          * @return bool|object statement object or result object
 390          */
 391         public static function p($sql) {
 392                 $a = get_app();
 393
 394                 $stamp1 = microtime(true);
 395
 396                 $params = self::getParam(func_get_args());
 397
 398                 // Renumber the array keys to be sure that they fit
 399                 $i = 0;
 400                 $args = [];
 401                 foreach ($params AS $param) {
 402                         // Avoid problems with some MySQL servers and boolean values. See issue #3645
 403                         if (is_bool($param)) {
 404                                 $param = (int)$param;
 405                         }
 406                         $args[++$i] = $param;
 407                 }
 408
 409                 if (!self::$connected) {
 410                         return false;
 411                 }
 412
 413                 if ((substr_count($sql, '?') != count($args)) && (count($args) > 0)) {
 414                         // Question: Should we continue or stop the query here?
 415                         logger('Parameter mismatch. Query "'.$sql.'" - Parameters '.print_r($args, true), LOGGER_DEBUG);
 416                 }
 417
 418                 $sql = self::cleanQuery($sql);
 419                 $sql = self::anyValueFallback($sql);
 420
 421                 $orig_sql = $sql;
 422
 423                 if ($a->getConfigValue('system', 'db_callstack')) {
 424                         $sql = "/*".System::callstack()." */ ".$sql;
 425                 }
 426
 427                 self::$error = '';
 428                 self::$errorno = 0;
 429                 self::$affected_rows = 0;
 430
 431                 // We have to make some things different if this function is called from "e"
 432                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
 433
 434                 if (isset($trace[1])) {
 435                         $called_from = $trace[1];
 436                 } else {
 437                         // We use just something that is defined to avoid warnings
 438                         $called_from = $trace[0];
 439                 }
 440                 // We are having an own error logging in the function "e"
 441                 $called_from_e = ($called_from['function'] == 'e');
 442
 443                 switch (self::$driver) {
 444                         case 'pdo':
 445                                 // If there are no arguments we use "query"
 446                                 if (count($args) == 0) {
 447                                         if (!$retval = self::$connection->query($sql)) {
 448                                                 $errorInfo = self::$connection->errorInfo();
 449                                                 self::$error = $errorInfo[2];
 450                                                 self::$errorno = $errorInfo[1];
 451                                                 $retval = false;
 452                                                 break;
 453                                         }
 454                                         self::$affected_rows = $retval->rowCount();
 455                                         break;
 456                                 }
 457
 458                                 if (!$stmt = self::$connection->prepare($sql)) {
 459                                         $errorInfo = self::$connection->errorInfo();
 460                                         self::$error = $errorInfo[2];
 461                                         self::$errorno = $errorInfo[1];
 462                                         $retval = false;
 463                                         break;
 464                                 }
 465
 466                                 foreach ($args AS $param => $value) {
 467                                         if (is_int($args[$param])) {
 468                                                 $data_type = PDO::PARAM_INT;
 469                                         } else {
 470                                                 $data_type = PDO::PARAM_STR;
 471                                         }
 472                                         $stmt->bindParam($param, $args[$param], $data_type);
 473                                 }
 474
 475                                 if (!$stmt->execute()) {
 476                                         $errorInfo = $stmt->errorInfo();
 477                                         self::$error = $errorInfo[2];
 478                                         self::$errorno = $errorInfo[1];
 479                                         $retval = false;
 480                                 } else {
 481                                         $retval = $stmt;
 482                                         self::$affected_rows = $retval->rowCount();
 483                                 }
 484                                 break;
 485                         case 'mysqli':
 486                                 // There are SQL statements that cannot be executed with a prepared statement
 487                                 $parts = explode(' ', $orig_sql);
 488                                 $command = strtolower($parts[0]);
 489                                 $can_be_prepared = in_array($command, ['select', 'update', 'insert', 'delete']);
 490
 491                                 // The fallback routine is called as well when there are no arguments
 492                                 if (!$can_be_prepared || (count($args) == 0)) {
 493                                         $retval = self::$connection->query(self::replaceParameters($sql, $args));
 494                                         if (self::$connection->errno) {
 495                                                 self::$error = self::$connection->error;
 496                                                 self::$errorno = self::$connection->errno;
 497                                                 $retval = false;
 498                                         } else {
 499                                                 if (isset($retval->num_rows)) {
 500                                                         self::$affected_rows = $retval->num_rows;
 501                                                 } else {
 502                                                         self::$affected_rows = self::$connection->affected_rows;
 503                                                 }
 504                                         }
 505                                         break;
 506                                 }
 507
 508                                 $stmt = self::$connection->stmt_init();
 509
 510                                 if (!$stmt->prepare($sql)) {
 511                                         self::$error = $stmt->error;
 512                                         self::$errorno = $stmt->errno;
 513                                         $retval = false;
 514                                         break;
 515                                 }
 516
 517                                 $param_types = '';
 518                                 $values = [];
 519                                 foreach ($args AS $param => $value) {
 520                                         if (is_int($args[$param])) {
 521                                                 $param_types .= 'i';
 522                                         } elseif (is_float($args[$param])) {
 523                                                 $param_types .= 'd';
 524                                         } elseif (is_string($args[$param])) {
 525                                                 $param_types .= 's';
 526                                         } else {
 527                                                 $param_types .= 'b';
 528                                         }
 529                                         $values[] = &$args[$param];
 530                                 }
 531
 532                                 if (count($values) > 0) {
 533                                         array_unshift($values, $param_types);
 534                                         call_user_func_array([$stmt, 'bind_param'], $values);
 535                                 }
 536
 537                                 if (!$stmt->execute()) {
 538                                         self::$error = self::$connection->error;
 539                                         self::$errorno = self::$connection->errno;
 540                                         $retval = false;
 541                                 } else {
 542                                         $stmt->store_result();
 543                                         $retval = $stmt;
 544                                         self::$affected_rows = $retval->affected_rows;
 545                                 }
 546                                 break;
 547                 }
 548
 549                 // We are having an own error logging in the function "e"
 550                 if ((self::$errorno != 0) && !$called_from_e) {
 551                         // We have to preserve the error code, somewhere in the logging it get lost
 552                         $error = self::$error;
 553                         $errorno = self::$errorno;
 554
 555                         logger('DB Error '.self::$errorno.': '.self::$error."\n".
 556                                 System::callstack(8)."\n".self::replaceParameters($sql, $args));
 557
 558                         // On a lost connection we try to reconnect - but only once.
 559                         if ($errorno == 2006) {
 560                                 if (self::$in_retrial || !self::reconnect()) {
 561                                         // It doesn't make sense to continue when the database connection was lost
 562                                         if (self::$in_retrial) {
 563                                                 logger('Giving up retrial because of database error '.$errorno.': '.$error);
 564                                         } else {
 565                                                 logger("Couldn't reconnect after database error ".$errorno.': '.$error);
 566                                         }
 567                                         exit(1);
 568                                 } else {
 569                                         // We try it again
 570                                         logger('Reconnected after database error '.$errorno.': '.$error);
 571                                         self::$in_retrial = true;
 572                                         $ret = self::p($sql, $args);
 573                                         self::$in_retrial = false;
 574                                         return $ret;
 575                                 }
 576                         }
 577
 578                         self::$error = $error;
 579                         self::$errorno = $errorno;
 580                 }
 581
 582                 $a->saveTimestamp($stamp1, 'database');
 583
 584                 if ($a->getConfigValue('system', 'db_log')) {
 585                         $stamp2 = microtime(true);
 586                         $duration = (float)($stamp2 - $stamp1);
 587
 588                         if (($duration > $a->getConfigValue('system', 'db_loglimit'))) {
 589                                 $duration = round($duration, 3);
 590                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 591
 592                                 @file_put_contents($a->getConfigValue('system', 'db_log'), DateTimeFormat::utcNow()."\t".$duration."\t".
 593                                                 basename($backtrace[1]["file"])."\t".
 594                                                 $backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
 595                                                 substr(self::replaceParameters($sql, $args), 0, 2000)."\n", FILE_APPEND);
 596                         }
 597                 }
 598                 return $retval;
 599         }
 600
 601         /**
 602          * @brief Executes a prepared statement like UPDATE or INSERT that doesn't return data
 603          *
 604          * Please use DBA::delete, DBA::insert, DBA::update, ... instead
 605          *
 606          * @param string $sql SQL statement
 607          * @return boolean Was the query successfull? False is returned only if an error occurred
 608          */
 609         public static function e($sql) {
 610                 $a = get_app();
 611
 612                 $stamp = microtime(true);
 613
 614                 $params = self::getParam(func_get_args());
 615
 616                 // In a case of a deadlock we are repeating the query 20 times
 617                 $timeout = 20;
 618
 619                 do {
 620                         $stmt = self::p($sql, $params);
 621
 622                         if (is_bool($stmt)) {
 623                                 $retval = $stmt;
 624                         } elseif (is_object($stmt)) {
 625                                 $retval = true;
 626                         } else {
 627                                 $retval = false;
 628                         }
 629
 630                         self::close($stmt);
 631
 632                 } while ((self::$errorno == 1213) && (--$timeout > 0));
 633
 634                 if (self::$errorno != 0) {
 635                         // We have to preserve the error code, somewhere in the logging it get lost
 636                         $error = self::$error;
 637                         $errorno = self::$errorno;
 638
 639                         logger('DB Error '.self::$errorno.': '.self::$error."\n".
 640                                 System::callstack(8)."\n".self::replaceParameters($sql, $params));
 641
 642                         // On a lost connection we simply quit.
 643                         // A reconnect like in self::p could be dangerous with modifications
 644                         if ($errorno == 2006) {
 645                                 logger('Giving up because of database error '.$errorno.': '.$error);
 646                                 exit(1);
 647                         }
 648
 649                         self::$error = $error;
 650                         self::$errorno = $errorno;
 651                 }
 652
 653                 $a->saveTimestamp($stamp, "database_write");
 654
 655                 return $retval;
 656         }
 657
 658         /**
 659          * @brief Check if data exists
 660          *
 661          * @param string $table Table name
 662          * @param array $condition array of fields for condition
 663          *
 664          * @return boolean Are there rows for that condition?
 665          */
 666         public static function exists($table, $condition) {
 667                 if (empty($table)) {
 668                         return false;
 669                 }
 670
 671                 $fields = [];
 672
 673                 if (empty($condition)) {
 674                         return DBStructure::existsTable($table);
 675                 }
 676
 677                 reset($condition);
 678                 $first_key = key($condition);
 679                 if (!is_int($first_key)) {
 680                         $fields = [$first_key];
 681                 }
 682
 683                 $stmt = self::select($table, $fields, $condition, ['limit' => 1]);
 684
 685                 if (is_bool($stmt)) {
 686                         $retval = $stmt;
 687                 } else {
 688                         $retval = (self::numRows($stmt) > 0);
 689                 }
 690
 691                 self::close($stmt);
 692
 693                 return $retval;
 694         }
 695
 696         /**
 697          * Fetches the first row
 698          *
 699          * Please use DBA::selectFirst or DBA::exists whenever this is possible.
 700          *
 701          * @brief Fetches the first row
 702          * @param string $sql SQL statement
 703          * @return array first row of query
 704          */
 705         public static function fetchFirst($sql) {
 706                 $params = self::getParam(func_get_args());
 707
 708                 $stmt = self::p($sql, $params);
 709
 710                 if (is_bool($stmt)) {
 711                         $retval = $stmt;
 712                 } else {
 713                         $retval = self::fetch($stmt);
 714                 }
 715
 716                 self::close($stmt);
 717
 718                 return $retval;
 719         }
 720
 721         /**
 722          * @brief Returns the number of affected rows of the last statement
 723          *
 724          * @return int Number of rows
 725          */
 726         public static function affectedRows() {
 727                 return self::$affected_rows;
 728         }
 729
 730         /**
 731          * @brief Returns the number of columns of a statement
 732          *
 733          * @param object Statement object
 734          * @return int Number of columns
 735          */
 736         public static function columnCount($stmt) {
 737                 if (!is_object($stmt)) {
 738                         return 0;
 739                 }
 740                 switch (self::$driver) {
 741                         case 'pdo':
 742                                 return $stmt->columnCount();
 743                         case 'mysqli':
 744                                 return $stmt->field_count;
 745                 }
 746                 return 0;
 747         }
 748         /**
 749          * @brief Returns the number of rows of a statement
 750          *
 751          * @param PDOStatement|mysqli_result|mysqli_stmt Statement object
 752          * @return int Number of rows
 753          */
 754         public static function numRows($stmt) {
 755                 if (!is_object($stmt)) {
 756                         return 0;
 757                 }
 758                 switch (self::$driver) {
 759                         case 'pdo':
 760                                 return $stmt->rowCount();
 761                         case 'mysqli':
 762                                 return $stmt->num_rows;
 763                 }
 764                 return 0;
 765         }
 766
 767         /**
 768          * @brief Fetch a single row
 769          *
 770          * @param mixed $stmt statement object
 771          * @return array current row
 772          */
 773         public static function fetch($stmt) {
 774                 $a = get_app();
 775
 776                 $stamp1 = microtime(true);
 777
 778                 $columns = [];
 779
 780                 if (!is_object($stmt)) {
 781                         return false;
 782                 }
 783
 784                 switch (self::$driver) {
 785                         case 'pdo':
 786                                 $columns = $stmt->fetch(PDO::FETCH_ASSOC);
 787                                 break;
 788                         case 'mysqli':
 789                                 if (get_class($stmt) == 'mysqli_result') {
 790                                         $columns = $stmt->fetch_assoc();
 791                                         break;
 792                                 }
 793
 794                                 // This code works, but is slow
 795
 796                                 // Bind the result to a result array
 797                                 $cols = [];
 798
 799                                 $cols_num = [];
 800                                 for ($x = 0; $x < $stmt->field_count; $x++) {
 801                                         $cols[] = &$cols_num[$x];
 802                                 }
 803
 804                                 call_user_func_array([$stmt, 'bind_result'], $cols);
 805
 806                                 if (!$stmt->fetch()) {
 807                                         return false;
 808                                 }
 809
 810                                 // The slow part:
 811                                 // We need to get the field names for the array keys
 812                                 // It seems that there is no better way to do this.
 813                                 $result = $stmt->result_metadata();
 814                                 $fields = $result->fetch_fields();
 815
 816                                 foreach ($cols_num AS $param => $col) {
 817                                         $columns[$fields[$param]->name] = $col;
 818                                 }
 819                 }
 820
 821                 $a->saveTimestamp($stamp1, 'database');
 822
 823                 return $columns;
 824         }
 825
 826         /**
 827          * @brief Insert a row into a table
 828          *
 829          * @param string $table Table name
 830          * @param array $param parameter array
 831          * @param bool $on_duplicate_update Do an update on a duplicate entry
 832          *
 833          * @return boolean was the insert successful?
 834          */
 835         public static function insert($table, $param, $on_duplicate_update = false) {
 836
 837                 if (empty($table) || empty($param)) {
 838                         logger('Table and fields have to be set');
 839                         return false;
 840                 }
 841
 842                 $sql = "INSERT INTO `".self::escape($table)."` (`".implode("`, `", array_keys($param))."`) VALUES (".
 843                         substr(str_repeat("?, ", count($param)), 0, -2).")";
 844
 845                 if ($on_duplicate_update) {
 846                         $sql .= " ON DUPLICATE KEY UPDATE `".implode("` = ?, `", array_keys($param))."` = ?";
 847
 848                         $values = array_values($param);
 849                         $param = array_merge_recursive($values, $values);
 850                 }
 851
 852                 return self::e($sql, $param);
 853         }
 854
 855         /**
 856          * @brief Fetch the id of the last insert command
 857          *
 858          * @return integer Last inserted id
 859          */
 860         public static function lastInsertId() {
 861                 switch (self::$driver) {
 862                         case 'pdo':
 863                                 $id = self::$connection->lastInsertId();
 864                                 break;
 865                         case 'mysqli':
 866                                 $id = self::$connection->insert_id;
 867                                 break;
 868                 }
 869                 return $id;
 870         }
 871
 872         /**
 873          * @brief Locks a table for exclusive write access
 874          *
 875          * This function can be extended in the future to accept a table array as well.
 876          *
 877          * @param string $table Table name
 878          *
 879          * @return boolean was the lock successful?
 880          */
 881         public static function lock($table) {
 882                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
 883                 if (self::$driver == 'pdo') {
 884                         self::e("SET autocommit=0");
 885                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
 886                 } else {
 887                         self::$connection->autocommit(false);
 888                 }
 889
 890                 $success = self::e("LOCK TABLES `".self::escape($table)."` WRITE");
 891
 892                 if (self::$driver == 'pdo') {
 893                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
 894                 }
 895
 896                 if (!$success) {
 897                         if (self::$driver == 'pdo') {
 898                                 self::e("SET autocommit=1");
 899                         } else {
 900                                 self::$connection->autocommit(true);
 901                         }
 902                 } else {
 903                         self::$in_transaction = true;
 904                 }
 905                 return $success;
 906         }
 907
 908         /**
 909          * @brief Unlocks all locked tables
 910          *
 911          * @return boolean was the unlock successful?
 912          */
 913         public static function unlock() {
 914                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
 915                 self::performCommit();
 916
 917                 if (self::$driver == 'pdo') {
 918                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
 919                 }
 920
 921                 $success = self::e("UNLOCK TABLES");
 922
 923                 if (self::$driver == 'pdo') {
 924                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
 925                         self::e("SET autocommit=1");
 926                 } else {
 927                         self::$connection->autocommit(true);
 928                 }
 929
 930                 self::$in_transaction = false;
 931                 return $success;
 932         }
 933
 934         /**
 935          * @brief Starts a transaction
 936          *
 937          * @return boolean Was the command executed successfully?
 938          */
 939         public static function transaction() {
 940                 if (!self::performCommit()) {
 941                         return false;
 942                 }
 943
 944                 switch (self::$driver) {
 945                         case 'pdo':
 946                                 if (!self::$connection->inTransaction() && !self::$connection->beginTransaction()) {
 947                                         return false;
 948                                 }
 949                                 break;
 950
 951                         case 'mysqli':
 952                                 if (!self::$connection->begin_transaction()) {
 953                                         return false;
 954                                 }
 955                                 break;
 956                 }
 957
 958                 self::$in_transaction = true;
 959                 return true;
 960         }
 961
 962         private static function performCommit()
 963         {
 964                 switch (self::$driver) {
 965                         case 'pdo':
 966                                 if (!self::$connection->inTransaction()) {
 967                                         return true;
 968                                 }
 969
 970                                 return self::$connection->commit();
 971
 972                         case 'mysqli':
 973                                 return self::$connection->commit();
 974                 }
 975
 976                 return true;
 977         }
 978
 979         /**
 980          * @brief Does a commit
 981          *
 982          * @return boolean Was the command executed successfully?
 983          */
 984         public static function commit() {
 985                 if (!self::performCommit()) {
 986                         return false;
 987                 }
 988                 self::$in_transaction = false;
 989                 return true;
 990         }
 991
 992         /**
 993          * @brief Does a rollback
 994          *
 995          * @return boolean Was the command executed successfully?
 996          */
 997         public static function rollback() {
 998                 $ret = false;
 999
1000                 switch (self::$driver) {
1001                         case 'pdo':
1002                                 if (!self::$connection->inTransaction()) {
1003                                         $ret = true;
1004                                         break;
1005                                 }
1006                                 $ret = self::$connection->rollBack();
1007                                 break;
1008
1009                         case 'mysqli':
1010                                 $ret = self::$connection->rollback();
1011                                 break;
1012                 }
1013                 self::$in_transaction = false;
1014                 return $ret;
1015         }
1016
1017         /**
1018          * @brief Build the array with the table relations
1019          *
1020          * The array is build from the database definitions in DBStructure.php
1021          *
1022          * This process must only be started once, since the value is cached.
1023          */
1024         private static function buildRelationData() {
1025                 $definition = DBStructure::definition();
1026
1027                 foreach ($definition AS $table => $structure) {
1028                         foreach ($structure['fields'] AS $field => $field_struct) {
1029                                 if (isset($field_struct['relation'])) {
1030                                         foreach ($field_struct['relation'] AS $rel_table => $rel_field) {
1031                                                 self::$relation[$rel_table][$rel_field][$table][] = $field;
1032                                         }
1033                                 }
1034                         }
1035                 }
1036         }
1037
1038         /**
1039          * @brief Delete a row from a table
1040          *
1041          * @param string  $table       Table name
1042          * @param array   $conditions  Field condition(s)
1043          * @param array   $options
1044          *                - cascade: If true we delete records in other tables that depend on the one we're deleting through
1045          *                           relations (default: true)
1046          * @param boolean $in_process  Internal use: Only do a commit after the last delete
1047          * @param array   $callstack   Internal use: prevent endless loops
1048          *
1049          * @return boolean|array was the delete successful? When $in_process is set: deletion data
1050          */
1051         public static function delete($table, array $conditions, array $options = [], $in_process = false, array &$callstack = [])
1052         {
1053                 if (empty($table) || empty($conditions)) {
1054                         logger('Table and conditions have to be set');
1055                         return false;
1056                 }
1057
1058                 $commands = [];
1059
1060                 // Create a key for the loop prevention
1061                 $key = $table . ':' . json_encode($conditions);
1062
1063                 // We quit when this key already exists in the callstack.
1064                 if (isset($callstack[$key])) {
1065                         return $commands;
1066                 }
1067
1068                 $callstack[$key] = true;
1069
1070                 $table = self::escape($table);
1071
1072                 $commands[$key] = ['table' => $table, 'conditions' => $conditions];
1073
1074                 // Don't use "defaults" here, since it would set "false" to "true"
1075                 if (isset($options['cascade'])) {
1076                         $cascade = $options['cascade'];
1077                 } else {
1078                         $cascade = true;
1079                 }
1080
1081                 // To speed up the whole process we cache the table relations
1082                 if ($cascade && count(self::$relation) == 0) {
1083                         self::buildRelationData();
1084                 }
1085
1086                 // Is there a relation entry for the table?
1087                 if ($cascade && isset(self::$relation[$table])) {
1088                         // We only allow a simple "one field" relation.
1089                         $field = array_keys(self::$relation[$table])[0];
1090                         $rel_def = array_values(self::$relation[$table])[0];
1091
1092                         // Create a key for preventing double queries
1093                         $qkey = $field . '-' . $table . ':' . json_encode($conditions);
1094
1095                         // When the search field is the relation field, we don't need to fetch the rows
1096                         // This is useful when the leading record is already deleted in the frontend but the rest is done in the backend
1097                         if ((count($conditions) == 1) && ($field == array_keys($conditions)[0])) {
1098                                 foreach ($rel_def AS $rel_table => $rel_fields) {
1099                                         foreach ($rel_fields AS $rel_field) {
1100                                                 $retval = self::delete($rel_table, [$rel_field => array_values($conditions)[0]], $options, true, $callstack);
1101                                                 $commands = array_merge($commands, $retval);
1102                                         }
1103                                 }
1104                                 // We quit when this key already exists in the callstack.
1105                         } elseif (!isset($callstack[$qkey])) {
1106
1107                                 $callstack[$qkey] = true;
1108
1109                                 // Fetch all rows that are to be deleted
1110                                 $data = self::select($table, [$field], $conditions);
1111
1112                                 while ($row = self::fetch($data)) {
1113                                         // Now we accumulate the delete commands
1114                                         $retval = self::delete($table, [$field => $row[$field]], $options, true, $callstack);
1115                                         $commands = array_merge($commands, $retval);
1116                                 }
1117
1118                                 self::close($data);
1119
1120                                 // Since we had split the delete command we don't need the original command anymore
1121                                 unset($commands[$key]);
1122                         }
1123                 }
1124
1125                 if (!$in_process) {
1126                         // Now we finalize the process
1127                         $do_transaction = !self::$in_transaction;
1128
1129                         if ($do_transaction) {
1130                                 self::transaction();
1131                         }
1132
1133                         $compacted = [];
1134                         $counter = [];
1135
1136                         foreach ($commands AS $command) {
1137                                 $conditions = $command['conditions'];
1138                                 reset($conditions);
1139                                 $first_key = key($conditions);
1140
1141                                 $condition_string = self::buildCondition($conditions);
1142
1143                                 if ((count($command['conditions']) > 1) || is_int($first_key)) {
1144                                         $sql = "DELETE FROM `" . $command['table'] . "`" . $condition_string;
1145                                         logger(self::replaceParameters($sql, $conditions), LOGGER_DATA);
1146
1147                                         if (!self::e($sql, $conditions)) {
1148                                                 if ($do_transaction) {
1149                                                         self::rollback();
1150                                                 }
1151                                                 return false;
1152                                         }
1153                                 } else {
1154                                         $key_table = $command['table'];
1155                                         $key_condition = array_keys($command['conditions'])[0];
1156                                         $value = array_values($command['conditions'])[0];
1157
1158                                         // Split the SQL queries in chunks of 100 values
1159                                         // We do the $i stuff here to make the code better readable
1160                                         $i = isset($counter[$key_table][$key_condition]) ? $counter[$key_table][$key_condition] : 0;
1161                                         if (isset($compacted[$key_table][$key_condition][$i]) && count($compacted[$key_table][$key_condition][$i]) > 100) {
1162                                                 ++$i;
1163                                         }
1164
1165                                         $compacted[$key_table][$key_condition][$i][$value] = $value;
1166                                         $counter[$key_table][$key_condition] = $i;
1167                                 }
1168                         }
1169                         foreach ($compacted AS $table => $values) {
1170                                 foreach ($values AS $field => $field_value_list) {
1171                                         foreach ($field_value_list AS $field_values) {
1172                                                 $sql = "DELETE FROM `" . $table . "` WHERE `" . $field . "` IN (" .
1173                                                         substr(str_repeat("?, ", count($field_values)), 0, -2) . ");";
1174
1175                                                 logger(self::replaceParameters($sql, $field_values), LOGGER_DATA);
1176
1177                                                 if (!self::e($sql, $field_values)) {
1178                                                         if ($do_transaction) {
1179                                                                 self::rollback();
1180                                                         }
1181                                                         return false;
1182                                                 }
1183                                         }
1184                                 }
1185                         }
1186                         if ($do_transaction) {
1187                                 self::commit();
1188                         }
1189                         return true;
1190                 }
1191
1192                 return $commands;
1193         }
1194
1195         /**
1196          * @brief Updates rows
1197          *
1198          * Updates rows in the database. When $old_fields is set to an array,
1199          * the system will only do an update if the fields in that array changed.
1200          *
1201          * Attention:
1202          * Only the values in $old_fields are compared.
1203          * This is an intentional behaviour.
1204          *
1205          * Example:
1206          * We include the timestamp field in $fields but not in $old_fields.
1207          * Then the row will only get the new timestamp when the other fields had changed.
1208          *
1209          * When $old_fields is set to a boolean value the system will do this compare itself.
1210          * When $old_fields is set to "true" the system will do an insert if the row doesn't exists.
1211          *
1212          * Attention:
1213          * Only set $old_fields to a boolean value when you are sure that you will update a single row.
1214          * When you set $old_fields to "true" then $fields must contain all relevant fields!
1215          *
1216          * @param string $table Table name
1217          * @param array $fields contains the fields that are updated
1218          * @param array $condition condition array with the key values
1219          * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate)
1220          *
1221          * @return boolean was the update successfull?
1222          */
1223         public static function update($table, $fields, $condition, $old_fields = []) {
1224
1225                 if (empty($table) || empty($fields) || empty($condition)) {
1226                         logger('Table, fields and condition have to be set');
1227                         return false;
1228                 }
1229
1230                 $table = self::escape($table);
1231
1232                 $condition_string = self::buildCondition($condition);
1233
1234                 if (is_bool($old_fields)) {
1235                         $do_insert = $old_fields;
1236
1237                         $old_fields = self::selectFirst($table, [], $condition);
1238
1239                         if (is_bool($old_fields)) {
1240                                 if ($do_insert) {
1241                                         $values = array_merge($condition, $fields);
1242                                         return self::insert($table, $values, $do_insert);
1243                                 }
1244                                 $old_fields = [];
1245                         }
1246                 }
1247
1248                 $do_update = (count($old_fields) == 0);
1249
1250                 foreach ($old_fields AS $fieldname => $content) {
1251                         if (isset($fields[$fieldname])) {
1252                                 if ($fields[$fieldname] == $content) {
1253                                         unset($fields[$fieldname]);
1254                                 } else {
1255                                         $do_update = true;
1256                                 }
1257                         }
1258                 }
1259
1260                 if (!$do_update || (count($fields) == 0)) {
1261                         return true;
1262                 }
1263
1264                 $sql = "UPDATE `".$table."` SET `".
1265                         implode("` = ?, `", array_keys($fields))."` = ?".$condition_string;
1266
1267                 $params1 = array_values($fields);
1268                 $params2 = array_values($condition);
1269                 $params = array_merge_recursive($params1, $params2);
1270
1271                 return self::e($sql, $params);
1272         }
1273
1274         /**
1275          * Retrieve a single record from a table and returns it in an associative array
1276          *
1277          * @brief Retrieve a single record from a table
1278          * @param string $table
1279          * @param array  $fields
1280          * @param array  $condition
1281          * @param array  $params
1282          * @return bool|array
1283          * @see self::select
1284          */
1285         public static function selectFirst($table, array $fields = [], array $condition = [], $params = [])
1286         {
1287                 $params['limit'] = 1;
1288                 $result = self::select($table, $fields, $condition, $params);
1289
1290                 if (is_bool($result)) {
1291                         return $result;
1292                 } else {
1293                         $row = self::fetch($result);
1294                         self::close($result);
1295                         return $row;
1296                 }
1297         }
1298
1299         /**
1300          * @brief Select rows from a table
1301          *
1302          * @param string $table     Table name
1303          * @param array  $fields    Array of selected fields, empty for all
1304          * @param array  $condition Array of fields for condition
1305          * @param array  $params    Array of several parameters
1306          *
1307          * @return boolean|object
1308          *
1309          * Example:
1310          * $table = "item";
1311          * $fields = array("id", "uri", "uid", "network");
1312          *
1313          * $condition = array("uid" => 1, "network" => 'dspr');
1314          * or:
1315          * $condition = array("`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr');
1316          *
1317          * $params = array("order" => array("id", "received" => true), "limit" => 10);
1318          *
1319          * $data = DBA::select($table, $fields, $condition, $params);
1320          */
1321         public static function select($table, array $fields = [], array $condition = [], array $params = [])
1322         {
1323                 if ($table == '') {
1324                         return false;
1325                 }
1326
1327                 $table = self::escape($table);
1328
1329                 if (count($fields) > 0) {
1330                         $select_fields = "`" . implode("`, `", array_values($fields)) . "`";
1331                 } else {
1332                         $select_fields = "*";
1333                 }
1334
1335                 $condition_string = self::buildCondition($condition);
1336
1337                 $param_string = self::buildParameter($params);
1338
1339                 $sql = "SELECT " . $select_fields . " FROM `" . $table . "`" . $condition_string . $param_string;
1340
1341                 $result = self::p($sql, $condition);
1342
1343                 return $result;
1344         }
1345
1346         /**
1347          * @brief Counts the rows from a table satisfying the provided condition
1348          *
1349          * @param string $table Table name
1350          * @param array $condition array of fields for condition
1351          *
1352          * @return int
1353          *
1354          * Example:
1355          * $table = "item";
1356          *
1357          * $condition = ["uid" => 1, "network" => 'dspr'];
1358          * or:
1359          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1360          *
1361          * $count = DBA::count($table, $condition);
1362          */
1363         public static function count($table, array $condition = [])
1364         {
1365                 if ($table == '') {
1366                         return false;
1367                 }
1368
1369                 $condition_string = self::buildCondition($condition);
1370
1371                 $sql = "SELECT COUNT(*) AS `count` FROM `".$table."`".$condition_string;
1372
1373                 $row = self::fetchFirst($sql, $condition);
1374
1375                 return $row['count'];
1376         }
1377
1378         /**
1379          * @brief Returns the SQL condition string built from the provided condition array
1380          *
1381          * This function operates with two modes.
1382          * - Supplied with a filed/value associative array, it builds simple strict
1383          *   equality conditions linked by AND.
1384          * - Supplied with a flat list, the first element is the condition string and
1385          *   the following arguments are the values to be interpolated
1386          *
1387          * $condition = ["uid" => 1, "network" => 'dspr'];
1388          * or:
1389          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1390          *
1391          * In either case, the provided array is left with the parameters only
1392          *
1393          * @param array $condition
1394          * @return string
1395          */
1396         public static function buildCondition(array &$condition = [])
1397         {
1398                 $condition_string = '';
1399                 if (count($condition) > 0) {
1400                         reset($condition);
1401                         $first_key = key($condition);
1402                         if (is_int($first_key)) {
1403                                 $condition_string = " WHERE (" . array_shift($condition) . ")";
1404                         } else {
1405                                 $new_values = [];
1406                                 $condition_string = "";
1407                                 foreach ($condition as $field => $value) {
1408                                         if ($condition_string != "") {
1409                                                 $condition_string .= " AND ";
1410                                         }
1411                                         if (is_array($value)) {
1412                                                 /* Workaround for MySQL Bug #64791.
1413                                                  * Never mix data types inside any IN() condition.
1414                                                  * In case of mixed types, cast all as string.
1415                                                  * Logic needs to be consistent with DBA::p() data types.
1416                                                  */
1417                                                 $is_int = false;
1418                                                 $is_alpha = false;
1419                                                 foreach ($value as $single_value) {
1420                                                         if (is_int($single_value)) {
1421                                                                 $is_int = true;
1422                                                         } else {
1423                                                                 $is_alpha = true;
1424                                                         }
1425                                                 }
1426
1427                                                 if ($is_int && $is_alpha) {
1428                                                         foreach ($value as &$ref) {
1429                                                                 if (is_int($ref)) {
1430                                                                         $ref = (string)$ref;
1431                                                                 }
1432                                                         }
1433                                                         unset($ref); //Prevent accidental re-use.
1434                                                 }
1435
1436                                                 $new_values = array_merge($new_values, array_values($value));
1437                                                 $placeholders = substr(str_repeat("?, ", count($value)), 0, -2);
1438                                                 $condition_string .= "`" . $field . "` IN (" . $placeholders . ")";
1439                                         } else {
1440                                                 $new_values[$field] = $value;
1441                                                 $condition_string .= "`" . $field . "` = ?";
1442                                         }
1443                                 }
1444                                 $condition_string = " WHERE (" . $condition_string . ")";
1445                                 $condition = $new_values;
1446                         }
1447                 }
1448
1449                 return $condition_string;
1450         }
1451
1452         /**
1453          * @brief Returns the SQL parameter string built from the provided parameter array
1454          *
1455          * @param array $params
1456          * @return string
1457          */
1458         public static function buildParameter(array $params = [])
1459         {
1460                 $order_string = '';
1461                 if (isset($params['order'])) {
1462                         $order_string = " ORDER BY ";
1463                         foreach ($params['order'] AS $fields => $order) {
1464                                 if (!is_int($fields)) {
1465                                         $order_string .= "`" . $fields . "` " . ($order ? "DESC" : "ASC") . ", ";
1466                                 } else {
1467                                         $order_string .= "`" . $order . "`, ";
1468                                 }
1469                         }
1470                         $order_string = substr($order_string, 0, -2);
1471                 }
1472
1473                 $limit_string = '';
1474                 if (isset($params['limit']) && is_int($params['limit'])) {
1475                         $limit_string = " LIMIT " . intval($params['limit']);
1476                 }
1477
1478                 if (isset($params['limit']) && is_array($params['limit'])) {
1479                         $limit_string = " LIMIT " . intval($params['limit'][0]) . ", " . intval($params['limit'][1]);
1480                 }
1481
1482                 return $order_string.$limit_string;
1483         }
1484
1485         /**
1486          * @brief Fills an array with data from a query
1487          *
1488          * @param object $stmt statement object
1489          * @return array Data array
1490          */
1491         public static function toArray($stmt, $do_close = true) {
1492                 if (is_bool($stmt)) {
1493                         return $stmt;
1494                 }
1495
1496                 $data = [];
1497                 while ($row = self::fetch($stmt)) {
1498                         $data[] = $row;
1499                 }
1500                 if ($do_close) {
1501                         self::close($stmt);
1502                 }
1503                 return $data;
1504         }
1505
1506         /**
1507          * @brief Returns the error number of the last query
1508          *
1509          * @return string Error number (0 if no error)
1510          */
1511         public static function errorNo() {
1512                 return self::$errorno;
1513         }
1514
1515         /**
1516          * @brief Returns the error message of the last query
1517          *
1518          * @return string Error message ('' if no error)
1519          */
1520         public static function errorMessage() {
1521                 return self::$error;
1522         }
1523
1524         /**
1525          * @brief Closes the current statement
1526          *
1527          * @param object $stmt statement object
1528          * @return boolean was the close successful?
1529          */
1530         public static function close($stmt) {
1531                 $a = get_app();
1532
1533                 $stamp1 = microtime(true);
1534
1535                 if (!is_object($stmt)) {
1536                         return false;
1537                 }
1538
1539                 switch (self::$driver) {
1540                         case 'pdo':
1541                                 $ret = $stmt->closeCursor();
1542                                 break;
1543                         case 'mysqli':
1544                                 // MySQLi offers both a mysqli_stmt and a mysqli_result class.
1545                                 // We should be careful not to assume the object type of $stmt
1546                                 // because DBA::p() has been able to return both types.
1547                                 if ($stmt instanceof mysqli_stmt) {
1548                                         $stmt->free_result();
1549                                         $ret = $stmt->close();
1550                                 } elseif ($stmt instanceof mysqli_result) {
1551                                         $stmt->free();
1552                                         $ret = true;
1553                                 } else {
1554                                         $ret = false;
1555                                 }
1556                                 break;
1557                 }
1558
1559                 $a->saveTimestamp($stamp1, 'database');
1560
1561                 return $ret;
1562         }
1563
1564         /**
1565          * @brief Return a list of database processes
1566          *
1567          * @return array
1568          *      'list' => List of processes, separated in their different states
1569          *      'amount' => Number of concurrent database processes
1570          */
1571         public static function processlist()
1572         {
1573                 $ret = self::p("SHOW PROCESSLIST");
1574                 $data = self::toArray($ret);
1575
1576                 $s = [];
1577
1578                 $processes = 0;
1579                 $states = [];
1580                 foreach ($data as $process) {
1581                         $state = trim($process["State"]);
1582
1583                         // Filter out all non blocking processes
1584                         if (!in_array($state, ["", "init", "statistics", "updating"])) {
1585                                 ++$states[$state];
1586                                 ++$processes;
1587                         }
1588                 }
1589
1590                 $statelist = "";
1591                 foreach ($states as $state => $usage) {
1592                         if ($statelist != "") {
1593                                 $statelist .= ", ";
1594                         }
1595                         $statelist .= $state.": ".$usage;
1596                 }
1597                 return(["list" => $statelist, "amount" => $processes]);
1598         }
1599
1600         /**
1601          * Checks if $array is a filled array with at least one entry.
1602          *
1603          * @param mixed $array A filled array with at least one entry
1604          *
1605          * @return boolean Whether $array is a filled array or an object with rows
1606          */
1607         public static function isResult($array)
1608         {
1609                 // It could be a return value from an update statement
1610                 if (is_bool($array)) {
1611                         return $array;
1612                 }
1613
1614                 if (is_object($array)) {
1615                         return self::numRows($array) > 0;
1616                 }
1617
1618                 return (is_array($array) && (count($array) > 0));
1619         }
1620
1621         /**
1622          * @brief Callback function for "esc_array"
1623          *
1624          * @param mixed   $value         Array value
1625          * @param string  $key           Array key
1626          * @param boolean $add_quotation add quotation marks for string values
1627          * @return void
1628          */
1629         private static function escapeArrayCallback(&$value, $key, $add_quotation)
1630         {
1631                 if (!$add_quotation) {
1632                         if (is_bool($value)) {
1633                                 $value = ($value ? '1' : '0');
1634                         } else {
1635                                 $value = self::escape($value);
1636                         }
1637                         return;
1638                 }
1639
1640                 if (is_bool($value)) {
1641                         $value = ($value ? 'true' : 'false');
1642                 } elseif (is_float($value) || is_integer($value)) {
1643                         $value = (string) $value;
1644                 } else {
1645                         $value = "'" . self::escape($value) . "'";
1646                 }
1647         }
1648
1649         /**
1650          * @brief Escapes a whole array
1651          *
1652          * @param mixed   $arr           Array with values to be escaped
1653          * @param boolean $add_quotation add quotation marks for string values
1654          * @return void
1655          */
1656         public static function escapeArray(&$arr, $add_quotation = false)
1657         {
1658                 array_walk($arr, 'self::escapeArrayCallback', $add_quotation);
1659         }
1660 }