src/Database/DBA.php

   1 <?php
   2
   3 namespace Friendica\Database;
   4
   5 use Friendica\Core\Config\Cache\IConfigCache;
   6 use Friendica\Core\System;
   7 use Friendica\Util\DateTimeFormat;
   8 use Friendica\Util\Profiler;
   9 use mysqli;
  10 use mysqli_result;
  11 use mysqli_stmt;
  12 use PDO;
  13 use PDOException;
  14 use PDOStatement;
  15 use Psr\Log\LoggerInterface;
  16
  17 /**
  18  * @class MySQL database class
  19  *
  20  * This class is for the low level database stuff that does driver specific things.
  21  */
  22 class DBA
  23 {
  24         /**
  25          * Lowest possible date value
  26          */
  27         const NULL_DATE     = '0001-01-01';
  28         /**
  29          * Lowest possible datetime value
  30          */
  31         const NULL_DATETIME = '0001-01-01 00:00:00';
  32
  33         public static $connected = false;
  34
  35         /**
  36          * @var IConfigCache
  37          */
  38         private static $configCache;
  39         /**
  40          * @var Profiler
  41          */
  42         private static $profiler;
  43         /**
  44          * @var LoggerInterface
  45          */
  46         private static $logger;
  47         /**
  48          * @var string
  49          */
  50         private static $basePath;
  51         private static $server_info = '';
  52         private static $connection;
  53         private static $driver;
  54         private static $error = false;
  55         private static $errorno = 0;
  56         private static $affected_rows = 0;
  57         private static $in_transaction = false;
  58         private static $in_retrial = false;
  59         private static $relation = [];
  60         private static $db_serveraddr = '';
  61         private static $db_user = '';
  62         private static $db_pass = '';
  63         private static $db_name = '';
  64         private static $db_charset = '';
  65
  66         public static function connect($basePath, IConfigCache $configCache, Profiler $profiler, LoggerInterface $logger, $serveraddr, $user, $pass, $db, $charset = null)
  67         {
  68                 if (!is_null(self::$connection) && self::connected()) {
  69                         return true;
  70                 }
  71
  72                 // We are storing these values for being able to perform a reconnect
  73                 self::$basePath = $basePath;
  74                 self::$configCache = $configCache;
  75                 self::$profiler = $profiler;
  76                 self::$logger = $logger;
  77                 self::$db_serveraddr = $serveraddr;
  78                 self::$db_user = $user;
  79                 self::$db_pass = $pass;
  80                 self::$db_name = $db;
  81                 self::$db_charset = $charset;
  82
  83                 $port = 0;
  84                 $serveraddr = trim($serveraddr);
  85
  86                 $serverdata = explode(':', $serveraddr);
  87                 $server = $serverdata[0];
  88
  89                 if (count($serverdata) > 1) {
  90                         $port = trim($serverdata[1]);
  91                 }
  92
  93                 $server = trim($server);
  94                 $user = trim($user);
  95                 $pass = trim($pass);
  96                 $db = trim($db);
  97                 $charset = trim($charset);
  98
  99                 if (!(strlen($server) && strlen($user))) {
 100                         return false;
 101                 }
 102
 103                 if (class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
 104                         self::$driver = 'pdo';
 105                         $connect = "mysql:host=".$server.";dbname=".$db;
 106
 107                         if ($port > 0) {
 108                                 $connect .= ";port=".$port;
 109                         }
 110
 111                         if ($charset) {
 112                                 $connect .= ";charset=".$charset;
 113                         }
 114
 115                         try {
 116                                 self::$connection = @new PDO($connect, $user, $pass);
 117                                 self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
 118                                 self::$connected = true;
 119                         } catch (PDOException $e) {
 120                                 /// @TODO At least log exception, don't ignore it!
 121                         }
 122                 }
 123
 124                 if (!self::$connected && class_exists('\mysqli')) {
 125                         self::$driver = 'mysqli';
 126
 127                         if ($port > 0) {
 128                                 self::$connection = @new mysqli($server, $user, $pass, $db, $port);
 129                         } else {
 130                                 self::$connection = @new mysqli($server, $user, $pass, $db);
 131                         }
 132
 133                         if (!mysqli_connect_errno()) {
 134                                 self::$connected = true;
 135
 136                                 if ($charset) {
 137                                         self::$connection->set_charset($charset);
 138                                 }
 139                         }
 140                 }
 141
 142                 // No suitable SQL driver was found.
 143                 if (!self::$connected) {
 144                         self::$driver = null;
 145                         self::$connection = null;
 146                 }
 147
 148                 return self::$connected;
 149         }
 150
 151         /**
 152          * Sets the logger for DBA
 153          *
 154          * @note this is necessary because if we want to load the logger configuration
 155          *       from the DB, but there's an error, we would print out an exception.
 156          *       So the logger gets updated after the logger configuration can be retrieved
 157          *       from the database
 158          *
 159          * @param LoggerInterface $logger
 160          */
 161         public static function setLogger(LoggerInterface $logger)
 162         {
 163                 self::$logger = $logger;
 164         }
 165
 166         /**
 167          * Disconnects the current database connection
 168          */
 169         public static function disconnect()
 170         {
 171                 if (is_null(self::$connection)) {
 172                         return;
 173                 }
 174
 175                 switch (self::$driver) {
 176                         case 'pdo':
 177                                 self::$connection = null;
 178                                 break;
 179                         case 'mysqli':
 180                                 self::$connection->close();
 181                                 self::$connection = null;
 182                                 break;
 183                 }
 184         }
 185
 186         /**
 187          * Perform a reconnect of an existing database connection
 188          */
 189         public static function reconnect() {
 190                 self::disconnect();
 191
 192                 $ret = self::connect(self::$basePath, self::$configCache, self::$profiler, self::$logger, self::$db_serveraddr, self::$db_user, self::$db_pass, self::$db_name, self::$db_charset);
 193                 return $ret;
 194         }
 195
 196         /**
 197          * Return the database object.
 198          * @return PDO|mysqli
 199          */
 200         public static function getConnection()
 201         {
 202                 return self::$connection;
 203         }
 204
 205         /**
 206          * @brief Returns the MySQL server version string
 207          *
 208          * This function discriminate between the deprecated mysql API and the current
 209          * object-oriented mysqli API. Example of returned string: 5.5.46-0+deb8u1
 210          *
 211          * @return string
 212          */
 213         public static function serverInfo() {
 214                 if (self::$server_info == '') {
 215                         switch (self::$driver) {
 216                                 case 'pdo':
 217                                         self::$server_info = self::$connection->getAttribute(PDO::ATTR_SERVER_VERSION);
 218                                         break;
 219                                 case 'mysqli':
 220                                         self::$server_info = self::$connection->server_info;
 221                                         break;
 222                         }
 223                 }
 224                 return self::$server_info;
 225         }
 226
 227         /**
 228          * @brief Returns the selected database name
 229          *
 230          * @return string
 231          * @throws \Exception
 232          */
 233         public static function databaseName() {
 234                 $ret = self::p("SELECT DATABASE() AS `db`");
 235                 $data = self::toArray($ret);
 236                 return $data[0]['db'];
 237         }
 238
 239         /**
 240          * @brief Analyze a database query and log this if some conditions are met.
 241          *
 242          * @param string $query The database query that will be analyzed
 243          * @throws \Exception
 244          */
 245         private static function logIndex($query) {
 246
 247                 if (!self::$configCache->get('system', 'db_log_index')) {
 248                         return;
 249                 }
 250
 251                 // Don't explain an explain statement
 252                 if (strtolower(substr($query, 0, 7)) == "explain") {
 253                         return;
 254                 }
 255
 256                 // Only do the explain on "select", "update" and "delete"
 257                 if (!in_array(strtolower(substr($query, 0, 6)), ["select", "update", "delete"])) {
 258                         return;
 259                 }
 260
 261                 $r = self::p("EXPLAIN ".$query);
 262                 if (!self::isResult($r)) {
 263                         return;
 264                 }
 265
 266                 $watchlist = explode(',', self::$configCache->get('system', 'db_log_index_watch'));
 267                 $blacklist = explode(',', self::$configCache->get('system', 'db_log_index_blacklist'));
 268
 269                 while ($row = self::fetch($r)) {
 270                         if ((intval(self::$configCache->get('system', 'db_loglimit_index')) > 0)) {
 271                                 $log = (in_array($row['key'], $watchlist) &&
 272                                         ($row['rows'] >= intval(self::$configCache->get('system', 'db_loglimit_index'))));
 273                         } else {
 274                                 $log = false;
 275                         }
 276
 277                         if ((intval(self::$configCache->get('system', 'db_loglimit_index_high')) > 0) && ($row['rows'] >= intval(self::$configCache->get('system', 'db_loglimit_index_high')))) {
 278                                 $log = true;
 279                         }
 280
 281                         if (in_array($row['key'], $blacklist) || ($row['key'] == "")) {
 282                                 $log = false;
 283                         }
 284
 285                         if ($log) {
 286                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 287                                 @file_put_contents(self::$configCache->get('system', 'db_log_index'), DateTimeFormat::utcNow()."\t".
 288                                                 $row['key']."\t".$row['rows']."\t".$row['Extra']."\t".
 289                                                 basename($backtrace[1]["file"])."\t".
 290                                                 $backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
 291                                                 substr($query, 0, 2000)."\n", FILE_APPEND);
 292                         }
 293                 }
 294         }
 295
 296         public static function escape($str) {
 297                 if (self::$connected) {
 298                         switch (self::$driver) {
 299                                 case 'pdo':
 300                                         return substr(@self::$connection->quote($str, PDO::PARAM_STR), 1, -1);
 301
 302                                 case 'mysqli':
 303                                         return @self::$connection->real_escape_string($str);
 304                         }
 305                 } else {
 306                         return str_replace("'", "\\'", $str);
 307                 }
 308         }
 309
 310         public static function connected() {
 311                 $connected = false;
 312
 313                 if (is_null(self::$connection)) {
 314                         return false;
 315                 }
 316
 317                 switch (self::$driver) {
 318                         case 'pdo':
 319                                 $r = self::p("SELECT 1");
 320                                 if (self::isResult($r)) {
 321                                         $row = self::toArray($r);
 322                                         $connected = ($row[0]['1'] == '1');
 323                                 }
 324                                 break;
 325                         case 'mysqli':
 326                                 $connected = self::$connection->ping();
 327                                 break;
 328                 }
 329                 return $connected;
 330         }
 331
 332         /**
 333          * @brief Replaces ANY_VALUE() function by MIN() function,
 334          *  if the database server does not support ANY_VALUE().
 335          *
 336          * Considerations for Standard SQL, or MySQL with ONLY_FULL_GROUP_BY (default since 5.7.5).
 337          * ANY_VALUE() is available from MySQL 5.7.5 https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html
 338          * A standard fall-back is to use MIN().
 339          *
 340          * @param string $sql An SQL string without the values
 341          * @return string The input SQL string modified if necessary.
 342          */
 343         public static function anyValueFallback($sql) {
 344                 $server_info = self::serverInfo();
 345                 if (version_compare($server_info, '5.7.5', '<') ||
 346                         (stripos($server_info, 'MariaDB') !== false)) {
 347                         $sql = str_ireplace('ANY_VALUE(', 'MIN(', $sql);
 348                 }
 349                 return $sql;
 350         }
 351
 352         /**
 353          * @brief beautifies the query - useful for "SHOW PROCESSLIST"
 354          *
 355          * This is safe when we bind the parameters later.
 356          * The parameter values aren't part of the SQL.
 357          *
 358          * @param string $sql An SQL string without the values
 359          * @return string The input SQL string modified if necessary.
 360          */
 361         public static function cleanQuery($sql) {
 362                 $search = ["\t", "\n", "\r", "  "];
 363                 $replace = [' ', ' ', ' ', ' '];
 364                 do {
 365                         $oldsql = $sql;
 366                         $sql = str_replace($search, $replace, $sql);
 367                 } while ($oldsql != $sql);
 368
 369                 return $sql;
 370         }
 371
 372
 373         /**
 374          * @brief Replaces the ? placeholders with the parameters in the $args array
 375          *
 376          * @param string $sql SQL query
 377          * @param array $args The parameters that are to replace the ? placeholders
 378          * @return string The replaced SQL query
 379          */
 380         private static function replaceParameters($sql, $args) {
 381                 $offset = 0;
 382                 foreach ($args AS $param => $value) {
 383                         if (is_int($args[$param]) || is_float($args[$param])) {
 384                                 $replace = intval($args[$param]);
 385                         } else {
 386                                 $replace = "'".self::escape($args[$param])."'";
 387                         }
 388
 389                         $pos = strpos($sql, '?', $offset);
 390                         if ($pos !== false) {
 391                                 $sql = substr_replace($sql, $replace, $pos, 1);
 392                         }
 393                         $offset = $pos + strlen($replace);
 394                 }
 395                 return $sql;
 396         }
 397
 398         /**
 399          * @brief Convert parameter array to an universal form
 400          * @param array $args Parameter array
 401          * @return array universalized parameter array
 402          */
 403         private static function getParam($args) {
 404                 unset($args[0]);
 405
 406                 // When the second function parameter is an array then use this as the parameter array
 407                 if ((count($args) > 0) && (is_array($args[1]))) {
 408                         return $args[1];
 409                 } else {
 410                         return $args;
 411                 }
 412         }
 413
 414         /**
 415          * @brief Executes a prepared statement that returns data
 416          * @usage Example: $r = p("SELECT * FROM `item` WHERE `guid` = ?", $guid);
 417          *
 418          * Please only use it with complicated queries.
 419          * For all regular queries please use DBA::select or DBA::exists
 420          *
 421          * @param string $sql SQL statement
 422          * @return bool|object statement object or result object
 423          * @throws \Exception
 424          */
 425         public static function p($sql) {
 426
 427                 $stamp1 = microtime(true);
 428
 429                 $params = self::getParam(func_get_args());
 430
 431                 // Renumber the array keys to be sure that they fit
 432                 $i = 0;
 433                 $args = [];
 434                 foreach ($params AS $param) {
 435                         // Avoid problems with some MySQL servers and boolean values. See issue #3645
 436                         if (is_bool($param)) {
 437                                 $param = (int)$param;
 438                         }
 439                         $args[++$i] = $param;
 440                 }
 441
 442                 if (!self::$connected) {
 443                         return false;
 444                 }
 445
 446                 if ((substr_count($sql, '?') != count($args)) && (count($args) > 0)) {
 447                         // Question: Should we continue or stop the query here?
 448                         self::$logger->warning('Query parameters mismatch.', ['query' => $sql, 'args' => $args, 'callstack' => System::callstack()]);
 449                 }
 450
 451                 $sql = self::cleanQuery($sql);
 452                 $sql = self::anyValueFallback($sql);
 453
 454                 $orig_sql = $sql;
 455
 456                 if (self::$configCache->get('system', 'db_callstack') !== null) {
 457                         $sql = "/*".System::callstack()." */ ".$sql;
 458                 }
 459
 460                 self::$error = '';
 461                 self::$errorno = 0;
 462                 self::$affected_rows = 0;
 463
 464                 // We have to make some things different if this function is called from "e"
 465                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
 466
 467                 if (isset($trace[1])) {
 468                         $called_from = $trace[1];
 469                 } else {
 470                         // We use just something that is defined to avoid warnings
 471                         $called_from = $trace[0];
 472                 }
 473                 // We are having an own error logging in the function "e"
 474                 $called_from_e = ($called_from['function'] == 'e');
 475
 476                 switch (self::$driver) {
 477                         case 'pdo':
 478                                 // If there are no arguments we use "query"
 479                                 if (count($args) == 0) {
 480                                         if (!$retval = self::$connection->query($sql)) {
 481                                                 $errorInfo = self::$connection->errorInfo();
 482                                                 self::$error = $errorInfo[2];
 483                                                 self::$errorno = $errorInfo[1];
 484                                                 $retval = false;
 485                                                 break;
 486                                         }
 487                                         self::$affected_rows = $retval->rowCount();
 488                                         break;
 489                                 }
 490
 491                                 if (!$stmt = self::$connection->prepare($sql)) {
 492                                         $errorInfo = self::$connection->errorInfo();
 493                                         self::$error = $errorInfo[2];
 494                                         self::$errorno = $errorInfo[1];
 495                                         $retval = false;
 496                                         break;
 497                                 }
 498
 499                                 foreach ($args AS $param => $value) {
 500                                         if (is_int($args[$param])) {
 501                                                 $data_type = PDO::PARAM_INT;
 502                                         } else {
 503                                                 $data_type = PDO::PARAM_STR;
 504                                         }
 505                                         $stmt->bindParam($param, $args[$param], $data_type);
 506                                 }
 507
 508                                 if (!$stmt->execute()) {
 509                                         $errorInfo = $stmt->errorInfo();
 510                                         self::$error = $errorInfo[2];
 511                                         self::$errorno = $errorInfo[1];
 512                                         $retval = false;
 513                                 } else {
 514                                         $retval = $stmt;
 515                                         self::$affected_rows = $retval->rowCount();
 516                                 }
 517                                 break;
 518                         case 'mysqli':
 519                                 // There are SQL statements that cannot be executed with a prepared statement
 520                                 $parts = explode(' ', $orig_sql);
 521                                 $command = strtolower($parts[0]);
 522                                 $can_be_prepared = in_array($command, ['select', 'update', 'insert', 'delete']);
 523
 524                                 // The fallback routine is called as well when there are no arguments
 525                                 if (!$can_be_prepared || (count($args) == 0)) {
 526                                         $retval = self::$connection->query(self::replaceParameters($sql, $args));
 527                                         if (self::$connection->errno) {
 528                                                 self::$error = self::$connection->error;
 529                                                 self::$errorno = self::$connection->errno;
 530                                                 $retval = false;
 531                                         } else {
 532                                                 if (isset($retval->num_rows)) {
 533                                                         self::$affected_rows = $retval->num_rows;
 534                                                 } else {
 535                                                         self::$affected_rows = self::$connection->affected_rows;
 536                                                 }
 537                                         }
 538                                         break;
 539                                 }
 540
 541                                 $stmt = self::$connection->stmt_init();
 542
 543                                 if (!$stmt->prepare($sql)) {
 544                                         self::$error = $stmt->error;
 545                                         self::$errorno = $stmt->errno;
 546                                         $retval = false;
 547                                         break;
 548                                 }
 549
 550                                 $param_types = '';
 551                                 $values = [];
 552                                 foreach ($args AS $param => $value) {
 553                                         if (is_int($args[$param])) {
 554                                                 $param_types .= 'i';
 555                                         } elseif (is_float($args[$param])) {
 556                                                 $param_types .= 'd';
 557                                         } elseif (is_string($args[$param])) {
 558                                                 $param_types .= 's';
 559                                         } else {
 560                                                 $param_types .= 'b';
 561                                         }
 562                                         $values[] = &$args[$param];
 563                                 }
 564
 565                                 if (count($values) > 0) {
 566                                         array_unshift($values, $param_types);
 567                                         call_user_func_array([$stmt, 'bind_param'], $values);
 568                                 }
 569
 570                                 if (!$stmt->execute()) {
 571                                         self::$error = self::$connection->error;
 572                                         self::$errorno = self::$connection->errno;
 573                                         $retval = false;
 574                                 } else {
 575                                         $stmt->store_result();
 576                                         $retval = $stmt;
 577                                         self::$affected_rows = $retval->affected_rows;
 578                                 }
 579                                 break;
 580                 }
 581
 582                 // We are having an own error logging in the function "e"
 583                 if ((self::$errorno != 0) && !$called_from_e) {
 584                         // We have to preserve the error code, somewhere in the logging it get lost
 585                         $error = self::$error;
 586                         $errorno = self::$errorno;
 587
 588                         self::$logger->error('DB Error', [
 589                                 'code'      => self::$errorno,
 590                                 'error'     => self::$error,
 591                                 'callstack' => System::callstack(8),
 592                                 'params'    => self::replaceParameters($sql, $args),
 593                         ]);
 594
 595                         // On a lost connection we try to reconnect - but only once.
 596                         if ($errorno == 2006) {
 597                                 if (self::$in_retrial || !self::reconnect()) {
 598                                         // It doesn't make sense to continue when the database connection was lost
 599                                         if (self::$in_retrial) {
 600                                                 self::$logger->notice('Giving up retrial because of database error', [
 601                                                         'code'  => self::$errorno,
 602                                                         'error' => self::$error,
 603                                                 ]);
 604                                         } else {
 605                                                 self::$logger->notice('Couldn\'t reconnect after database error', [
 606                                                         'code'  => self::$errorno,
 607                                                         'error' => self::$error,
 608                                                 ]);
 609                                         }
 610                                         exit(1);
 611                                 } else {
 612                                         // We try it again
 613                                         self::$logger->notice('Reconnected after database error', [
 614                                                 'code'  => self::$errorno,
 615                                                 'error' => self::$error,
 616                                         ]);
 617                                         self::$in_retrial = true;
 618                                         $ret = self::p($sql, $args);
 619                                         self::$in_retrial = false;
 620                                         return $ret;
 621                                 }
 622                         }
 623
 624                         self::$error = $error;
 625                         self::$errorno = $errorno;
 626                 }
 627
 628                 self::$profiler->saveTimestamp($stamp1, 'database', System::callstack());
 629
 630                 if (self::$configCache->get('system', 'db_log')) {
 631                         $stamp2 = microtime(true);
 632                         $duration = (float)($stamp2 - $stamp1);
 633
 634                         if (($duration > self::$configCache->get('system', 'db_loglimit'))) {
 635                                 $duration = round($duration, 3);
 636                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 637
 638                                 @file_put_contents(self::$configCache->get('system', 'db_log'), DateTimeFormat::utcNow()."\t".$duration."\t".
 639                                                 basename($backtrace[1]["file"])."\t".
 640                                                 $backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
 641                                                 substr(self::replaceParameters($sql, $args), 0, 2000)."\n", FILE_APPEND);
 642                         }
 643                 }
 644                 return $retval;
 645         }
 646
 647         /**
 648          * @brief Executes a prepared statement like UPDATE or INSERT that doesn't return data
 649          *
 650          * Please use DBA::delete, DBA::insert, DBA::update, ... instead
 651          *
 652          * @param string $sql SQL statement
 653          * @return boolean Was the query successfull? False is returned only if an error occurred
 654          * @throws \Exception
 655          */
 656         public static function e($sql) {
 657
 658                 $stamp = microtime(true);
 659
 660                 $params = self::getParam(func_get_args());
 661
 662                 // In a case of a deadlock we are repeating the query 20 times
 663                 $timeout = 20;
 664
 665                 do {
 666                         $stmt = self::p($sql, $params);
 667
 668                         if (is_bool($stmt)) {
 669                                 $retval = $stmt;
 670                         } elseif (is_object($stmt)) {
 671                                 $retval = true;
 672                         } else {
 673                                 $retval = false;
 674                         }
 675
 676                         self::close($stmt);
 677
 678                 } while ((self::$errorno == 1213) && (--$timeout > 0));
 679
 680                 if (self::$errorno != 0) {
 681                         // We have to preserve the error code, somewhere in the logging it get lost
 682                         $error = self::$error;
 683                         $errorno = self::$errorno;
 684
 685                         self::$logger->error('DB Error', [
 686                                 'code'      => self::$errorno,
 687                                 'error'     => self::$error,
 688                                 'callstack' => System::callstack(8),
 689                                 'params'    => self::replaceParameters($sql, $params),
 690                         ]);
 691
 692                         // On a lost connection we simply quit.
 693                         // A reconnect like in self::p could be dangerous with modifications
 694                         if ($errorno == 2006) {
 695                                 self::$logger->error('Giving up because of database error', [
 696                                         'code'  => self::$errorno,
 697                                         'error' => self::$error,
 698                                 ]);
 699                                 exit(1);
 700                         }
 701
 702                         self::$error = $error;
 703                         self::$errorno = $errorno;
 704                 }
 705
 706                 self::$profiler->saveTimestamp($stamp, "database_write", System::callstack());
 707
 708                 return $retval;
 709         }
 710
 711         /**
 712          * @brief Check if data exists
 713          *
 714          * @param string $table     Table name
 715          * @param array  $condition array of fields for condition
 716          *
 717          * @return boolean Are there rows for that condition?
 718          * @throws \Exception
 719          */
 720         public static function exists($table, $condition) {
 721                 if (empty($table)) {
 722                         return false;
 723                 }
 724
 725                 $fields = [];
 726
 727                 if (empty($condition)) {
 728                         return DBStructure::existsTable($table);
 729                 }
 730
 731                 reset($condition);
 732                 $first_key = key($condition);
 733                 if (!is_int($first_key)) {
 734                         $fields = [$first_key];
 735                 }
 736
 737                 $stmt = self::select($table, $fields, $condition, ['limit' => 1]);
 738
 739                 if (is_bool($stmt)) {
 740                         $retval = $stmt;
 741                 } else {
 742                         $retval = (self::numRows($stmt) > 0);
 743                 }
 744
 745                 self::close($stmt);
 746
 747                 return $retval;
 748         }
 749
 750         /**
 751          * Fetches the first row
 752          *
 753          * Please use DBA::selectFirst or DBA::exists whenever this is possible.
 754          *
 755          * @brief Fetches the first row
 756          * @param string $sql SQL statement
 757          * @return array first row of query
 758          * @throws \Exception
 759          */
 760         public static function fetchFirst($sql) {
 761                 $params = self::getParam(func_get_args());
 762
 763                 $stmt = self::p($sql, $params);
 764
 765                 if (is_bool($stmt)) {
 766                         $retval = $stmt;
 767                 } else {
 768                         $retval = self::fetch($stmt);
 769                 }
 770
 771                 self::close($stmt);
 772
 773                 return $retval;
 774         }
 775
 776         /**
 777          * @brief Returns the number of affected rows of the last statement
 778          *
 779          * @return int Number of rows
 780          */
 781         public static function affectedRows() {
 782                 return self::$affected_rows;
 783         }
 784
 785         /**
 786          * @brief Returns the number of columns of a statement
 787          *
 788          * @param object Statement object
 789          * @return int Number of columns
 790          */
 791         public static function columnCount($stmt) {
 792                 if (!is_object($stmt)) {
 793                         return 0;
 794                 }
 795                 switch (self::$driver) {
 796                         case 'pdo':
 797                                 return $stmt->columnCount();
 798                         case 'mysqli':
 799                                 return $stmt->field_count;
 800                 }
 801                 return 0;
 802         }
 803         /**
 804          * @brief Returns the number of rows of a statement
 805          *
 806          * @param PDOStatement|mysqli_result|mysqli_stmt Statement object
 807          * @return int Number of rows
 808          */
 809         public static function numRows($stmt) {
 810                 if (!is_object($stmt)) {
 811                         return 0;
 812                 }
 813                 switch (self::$driver) {
 814                         case 'pdo':
 815                                 return $stmt->rowCount();
 816                         case 'mysqli':
 817                                 return $stmt->num_rows;
 818                 }
 819                 return 0;
 820         }
 821
 822         /**
 823          * @brief Fetch a single row
 824          *
 825          * @param mixed $stmt statement object
 826          * @return array current row
 827          */
 828         public static function fetch($stmt) {
 829
 830                 $stamp1 = microtime(true);
 831
 832                 $columns = [];
 833
 834                 if (!is_object($stmt)) {
 835                         return false;
 836                 }
 837
 838                 switch (self::$driver) {
 839                         case 'pdo':
 840                                 $columns = $stmt->fetch(PDO::FETCH_ASSOC);
 841                                 break;
 842                         case 'mysqli':
 843                                 if (get_class($stmt) == 'mysqli_result') {
 844                                         $columns = $stmt->fetch_assoc();
 845                                         break;
 846                                 }
 847
 848                                 // This code works, but is slow
 849
 850                                 // Bind the result to a result array
 851                                 $cols = [];
 852
 853                                 $cols_num = [];
 854                                 for ($x = 0; $x < $stmt->field_count; $x++) {
 855                                         $cols[] = &$cols_num[$x];
 856                                 }
 857
 858                                 call_user_func_array([$stmt, 'bind_result'], $cols);
 859
 860                                 if (!$stmt->fetch()) {
 861                                         return false;
 862                                 }
 863
 864                                 // The slow part:
 865                                 // We need to get the field names for the array keys
 866                                 // It seems that there is no better way to do this.
 867                                 $result = $stmt->result_metadata();
 868                                 $fields = $result->fetch_fields();
 869
 870                                 foreach ($cols_num AS $param => $col) {
 871                                         $columns[$fields[$param]->name] = $col;
 872                                 }
 873                 }
 874
 875                 self::$profiler->saveTimestamp($stamp1, 'database', System::callstack());
 876
 877                 return $columns;
 878         }
 879
 880         /**
 881          * @brief Insert a row into a table
 882          *
 883          * @param string $table               Table name
 884          * @param array  $param               parameter array
 885          * @param bool   $on_duplicate_update Do an update on a duplicate entry
 886          *
 887          * @return boolean was the insert successful?
 888          * @throws \Exception
 889          */
 890         public static function insert($table, $param, $on_duplicate_update = false) {
 891
 892                 if (empty($table) || empty($param)) {
 893                         self::$logger->info('Table and fields have to be set');
 894                         return false;
 895                 }
 896
 897                 $sql = "INSERT INTO `".self::escape($table)."` (`".implode("`, `", array_keys($param))."`) VALUES (".
 898                         substr(str_repeat("?, ", count($param)), 0, -2).")";
 899
 900                 if ($on_duplicate_update) {
 901                         $sql .= " ON DUPLICATE KEY UPDATE `".implode("` = ?, `", array_keys($param))."` = ?";
 902
 903                         $values = array_values($param);
 904                         $param = array_merge_recursive($values, $values);
 905                 }
 906
 907                 return self::e($sql, $param);
 908         }
 909
 910         /**
 911          * @brief Fetch the id of the last insert command
 912          *
 913          * @return integer Last inserted id
 914          */
 915         public static function lastInsertId() {
 916                 switch (self::$driver) {
 917                         case 'pdo':
 918                                 $id = self::$connection->lastInsertId();
 919                                 break;
 920                         case 'mysqli':
 921                                 $id = self::$connection->insert_id;
 922                                 break;
 923                 }
 924                 return $id;
 925         }
 926
 927         /**
 928          * @brief Locks a table for exclusive write access
 929          *
 930          * This function can be extended in the future to accept a table array as well.
 931          *
 932          * @param string $table Table name
 933          *
 934          * @return boolean was the lock successful?
 935          * @throws \Exception
 936          */
 937         public static function lock($table) {
 938                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
 939                 if (self::$driver == 'pdo') {
 940                         self::e("SET autocommit=0");
 941                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
 942                 } else {
 943                         self::$connection->autocommit(false);
 944                 }
 945
 946                 $success = self::e("LOCK TABLES `".self::escape($table)."` WRITE");
 947
 948                 if (self::$driver == 'pdo') {
 949                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
 950                 }
 951
 952                 if (!$success) {
 953                         if (self::$driver == 'pdo') {
 954                                 self::e("SET autocommit=1");
 955                         } else {
 956                                 self::$connection->autocommit(true);
 957                         }
 958                 } else {
 959                         self::$in_transaction = true;
 960                 }
 961                 return $success;
 962         }
 963
 964         /**
 965          * @brief Unlocks all locked tables
 966          *
 967          * @return boolean was the unlock successful?
 968          * @throws \Exception
 969          */
 970         public static function unlock() {
 971                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
 972                 self::performCommit();
 973
 974                 if (self::$driver == 'pdo') {
 975                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
 976                 }
 977
 978                 $success = self::e("UNLOCK TABLES");
 979
 980                 if (self::$driver == 'pdo') {
 981                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
 982                         self::e("SET autocommit=1");
 983                 } else {
 984                         self::$connection->autocommit(true);
 985                 }
 986
 987                 self::$in_transaction = false;
 988                 return $success;
 989         }
 990
 991         /**
 992          * @brief Starts a transaction
 993          *
 994          * @return boolean Was the command executed successfully?
 995          */
 996         public static function transaction() {
 997                 if (!self::performCommit()) {
 998                         return false;
 999                 }
1000
1001                 switch (self::$driver) {
1002                         case 'pdo':
1003                                 if (!self::$connection->inTransaction() && !self::$connection->beginTransaction()) {
1004                                         return false;
1005                                 }
1006                                 break;
1007
1008                         case 'mysqli':
1009                                 if (!self::$connection->begin_transaction()) {
1010                                         return false;
1011                                 }
1012                                 break;
1013                 }
1014
1015                 self::$in_transaction = true;
1016                 return true;
1017         }
1018
1019         private static function performCommit()
1020         {
1021                 switch (self::$driver) {
1022                         case 'pdo':
1023                                 if (!self::$connection->inTransaction()) {
1024                                         return true;
1025                                 }
1026
1027                                 return self::$connection->commit();
1028
1029                         case 'mysqli':
1030                                 return self::$connection->commit();
1031                 }
1032
1033                 return true;
1034         }
1035
1036         /**
1037          * @brief Does a commit
1038          *
1039          * @return boolean Was the command executed successfully?
1040          */
1041         public static function commit() {
1042                 if (!self::performCommit()) {
1043                         return false;
1044                 }
1045                 self::$in_transaction = false;
1046                 return true;
1047         }
1048
1049         /**
1050          * @brief Does a rollback
1051          *
1052          * @return boolean Was the command executed successfully?
1053          */
1054         public static function rollback() {
1055                 $ret = false;
1056
1057                 switch (self::$driver) {
1058                         case 'pdo':
1059                                 if (!self::$connection->inTransaction()) {
1060                                         $ret = true;
1061                                         break;
1062                                 }
1063                                 $ret = self::$connection->rollBack();
1064                                 break;
1065
1066                         case 'mysqli':
1067                                 $ret = self::$connection->rollback();
1068                                 break;
1069                 }
1070                 self::$in_transaction = false;
1071                 return $ret;
1072         }
1073
1074         /**
1075          * @brief Build the array with the table relations
1076          *
1077          * The array is build from the database definitions in DBStructure.php
1078          *
1079          * This process must only be started once, since the value is cached.
1080          */
1081         private static function buildRelationData() {
1082                 $definition = DBStructure::definition(self::$basePath);
1083
1084                 foreach ($definition AS $table => $structure) {
1085                         foreach ($structure['fields'] AS $field => $field_struct) {
1086                                 if (isset($field_struct['relation'])) {
1087                                         foreach ($field_struct['relation'] AS $rel_table => $rel_field) {
1088                                                 self::$relation[$rel_table][$rel_field][$table][] = $field;
1089                                         }
1090                                 }
1091                         }
1092                 }
1093         }
1094
1095         /**
1096          * @brief Delete a row from a table
1097          *
1098          * @param string $table      Table name
1099          * @param array  $conditions Field condition(s)
1100          * @param array  $options
1101          *                           - cascade: If true we delete records in other tables that depend on the one we're deleting through
1102          *                           relations (default: true)
1103          * @param array  $callstack  Internal use: prevent endless loops
1104          *
1105          * @return boolean was the delete successful?
1106          * @throws \Exception
1107          */
1108         public static function delete($table, array $conditions, array $options = [], array &$callstack = [])
1109         {
1110                 if (empty($table) || empty($conditions)) {
1111                         self::$logger->info('Table and conditions have to be set');
1112                         return false;
1113                 }
1114
1115                 $commands = [];
1116
1117                 // Create a key for the loop prevention
1118                 $key = $table . ':' . json_encode($conditions);
1119
1120                 // We quit when this key already exists in the callstack.
1121                 if (isset($callstack[$key])) {
1122                         return $commands;
1123                 }
1124
1125                 $callstack[$key] = true;
1126
1127                 $table = self::escape($table);
1128
1129                 $commands[$key] = ['table' => $table, 'conditions' => $conditions];
1130
1131                 // Don't use "defaults" here, since it would set "false" to "true"
1132                 if (isset($options['cascade'])) {
1133                         $cascade = $options['cascade'];
1134                 } else {
1135                         $cascade = true;
1136                 }
1137
1138                 // To speed up the whole process we cache the table relations
1139                 if ($cascade && count(self::$relation) == 0) {
1140                         self::buildRelationData();
1141                 }
1142
1143                 // Is there a relation entry for the table?
1144                 if ($cascade && isset(self::$relation[$table])) {
1145                         // We only allow a simple "one field" relation.
1146                         $field = array_keys(self::$relation[$table])[0];
1147                         $rel_def = array_values(self::$relation[$table])[0];
1148
1149                         // Create a key for preventing double queries
1150                         $qkey = $field . '-' . $table . ':' . json_encode($conditions);
1151
1152                         // When the search field is the relation field, we don't need to fetch the rows
1153                         // This is useful when the leading record is already deleted in the frontend but the rest is done in the backend
1154                         if ((count($conditions) == 1) && ($field == array_keys($conditions)[0])) {
1155                                 foreach ($rel_def AS $rel_table => $rel_fields) {
1156                                         foreach ($rel_fields AS $rel_field) {
1157                                                 self::delete($rel_table, [$rel_field => array_values($conditions)[0]], $options, $callstack);
1158                                         }
1159                                 }
1160                                 // We quit when this key already exists in the callstack.
1161                         } elseif (!isset($callstack[$qkey])) {
1162                                 $callstack[$qkey] = true;
1163
1164                                 // Fetch all rows that are to be deleted
1165                                 $data = self::select($table, [$field], $conditions);
1166
1167                                 while ($row = self::fetch($data)) {
1168                                         self::delete($table, [$field => $row[$field]], $options, $callstack);
1169                                 }
1170
1171                                 self::close($data);
1172
1173                                 // Since we had split the delete command we don't need the original command anymore
1174                                 unset($commands[$key]);
1175                         }
1176                 }
1177
1178                 // Now we finalize the process
1179                 $do_transaction = !self::$in_transaction;
1180
1181                 if ($do_transaction) {
1182                         self::transaction();
1183                 }
1184
1185                 $compacted = [];
1186                 $counter = [];
1187
1188                 foreach ($commands AS $command) {
1189                         $conditions = $command['conditions'];
1190                         reset($conditions);
1191                         $first_key = key($conditions);
1192
1193                         $condition_string = self::buildCondition($conditions);
1194
1195                         if ((count($command['conditions']) > 1) || is_int($first_key)) {
1196                                 $sql = "DELETE FROM `" . $command['table'] . "`" . $condition_string;
1197                                 self::$logger->debug(self::replaceParameters($sql, $conditions));
1198
1199                                 if (!self::e($sql, $conditions)) {
1200                                         if ($do_transaction) {
1201                                                 self::rollback();
1202                                         }
1203                                         return false;
1204                                 }
1205                         } else {
1206                                 $key_table = $command['table'];
1207                                 $key_condition = array_keys($command['conditions'])[0];
1208                                 $value = array_values($command['conditions'])[0];
1209
1210                                 // Split the SQL queries in chunks of 100 values
1211                                 // We do the $i stuff here to make the code better readable
1212                                 $i = isset($counter[$key_table][$key_condition]) ? $counter[$key_table][$key_condition] : 0;
1213                                 if (isset($compacted[$key_table][$key_condition][$i]) && count($compacted[$key_table][$key_condition][$i]) > 100) {
1214                                         ++$i;
1215                                 }
1216
1217                                 $compacted[$key_table][$key_condition][$i][$value] = $value;
1218                                 $counter[$key_table][$key_condition] = $i;
1219                         }
1220                 }
1221                 foreach ($compacted AS $table => $values) {
1222                         foreach ($values AS $field => $field_value_list) {
1223                                 foreach ($field_value_list AS $field_values) {
1224                                         $sql = "DELETE FROM `" . $table . "` WHERE `" . $field . "` IN (" .
1225                                                 substr(str_repeat("?, ", count($field_values)), 0, -2) . ");";
1226
1227                                         self::$logger->debug(self::replaceParameters($sql, $field_values));
1228
1229                                         if (!self::e($sql, $field_values)) {
1230                                                 if ($do_transaction) {
1231                                                         self::rollback();
1232                                                 }
1233                                                 return false;
1234                                         }
1235                                 }
1236                         }
1237                 }
1238                 if ($do_transaction) {
1239                         self::commit();
1240                 }
1241                 return true;
1242         }
1243
1244         /**
1245          * @brief Updates rows
1246          *
1247          * Updates rows in the database. When $old_fields is set to an array,
1248          * the system will only do an update if the fields in that array changed.
1249          *
1250          * Attention:
1251          * Only the values in $old_fields are compared.
1252          * This is an intentional behaviour.
1253          *
1254          * Example:
1255          * We include the timestamp field in $fields but not in $old_fields.
1256          * Then the row will only get the new timestamp when the other fields had changed.
1257          *
1258          * When $old_fields is set to a boolean value the system will do this compare itself.
1259          * When $old_fields is set to "true" the system will do an insert if the row doesn't exists.
1260          *
1261          * Attention:
1262          * Only set $old_fields to a boolean value when you are sure that you will update a single row.
1263          * When you set $old_fields to "true" then $fields must contain all relevant fields!
1264          *
1265          * @param string        $table      Table name
1266          * @param array         $fields     contains the fields that are updated
1267          * @param array         $condition  condition array with the key values
1268          * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate)
1269          *
1270          * @return boolean was the update successfull?
1271          * @throws \Exception
1272          */
1273         public static function update($table, $fields, $condition, $old_fields = []) {
1274
1275                 if (empty($table) || empty($fields) || empty($condition)) {
1276                         self::$logger->info('Table, fields and condition have to be set');
1277                         return false;
1278                 }
1279
1280                 $table = self::escape($table);
1281
1282                 $condition_string = self::buildCondition($condition);
1283
1284                 if (is_bool($old_fields)) {
1285                         $do_insert = $old_fields;
1286
1287                         $old_fields = self::selectFirst($table, [], $condition);
1288
1289                         if (is_bool($old_fields)) {
1290                                 if ($do_insert) {
1291                                         $values = array_merge($condition, $fields);
1292                                         return self::insert($table, $values, $do_insert);
1293                                 }
1294                                 $old_fields = [];
1295                         }
1296                 }
1297
1298                 $do_update = (count($old_fields) == 0);
1299
1300                 foreach ($old_fields AS $fieldname => $content) {
1301                         if (isset($fields[$fieldname])) {
1302                                 if (($fields[$fieldname] == $content) && !is_null($content)) {
1303                                         unset($fields[$fieldname]);
1304                                 } else {
1305                                         $do_update = true;
1306                                 }
1307                         }
1308                 }
1309
1310                 if (!$do_update || (count($fields) == 0)) {
1311                         return true;
1312                 }
1313
1314                 $sql = "UPDATE `".$table."` SET `".
1315                         implode("` = ?, `", array_keys($fields))."` = ?".$condition_string;
1316
1317                 $params1 = array_values($fields);
1318                 $params2 = array_values($condition);
1319                 $params = array_merge_recursive($params1, $params2);
1320
1321                 return self::e($sql, $params);
1322         }
1323
1324         /**
1325          * Retrieve a single record from a table and returns it in an associative array
1326          *
1327          * @brief Retrieve a single record from a table
1328          * @param string $table
1329          * @param array  $fields
1330          * @param array  $condition
1331          * @param array  $params
1332          * @return bool|array
1333          * @throws \Exception
1334          * @see   self::select
1335          */
1336         public static function selectFirst($table, array $fields = [], array $condition = [], $params = [])
1337         {
1338                 $params['limit'] = 1;
1339                 $result = self::select($table, $fields, $condition, $params);
1340
1341                 if (is_bool($result)) {
1342                         return $result;
1343                 } else {
1344                         $row = self::fetch($result);
1345                         self::close($result);
1346                         return $row;
1347                 }
1348         }
1349
1350         /**
1351          * @brief Select rows from a table
1352          *
1353          * @param string $table     Table name
1354          * @param array  $fields    Array of selected fields, empty for all
1355          * @param array  $condition Array of fields for condition
1356          * @param array  $params    Array of several parameters
1357          *
1358          * @return boolean|object
1359          *
1360          * Example:
1361          * $table = "item";
1362          * $fields = array("id", "uri", "uid", "network");
1363          *
1364          * $condition = array("uid" => 1, "network" => 'dspr');
1365          * or:
1366          * $condition = array("`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr');
1367          *
1368          * $params = array("order" => array("id", "received" => true), "limit" => 10);
1369          *
1370          * $data = DBA::select($table, $fields, $condition, $params);
1371          * @throws \Exception
1372          */
1373         public static function select($table, array $fields = [], array $condition = [], array $params = [])
1374         {
1375                 if ($table == '') {
1376                         return false;
1377                 }
1378
1379                 $table = self::escape($table);
1380
1381                 if (count($fields) > 0) {
1382                         $select_fields = "`" . implode("`, `", array_values($fields)) . "`";
1383                 } else {
1384                         $select_fields = "*";
1385                 }
1386
1387                 $condition_string = self::buildCondition($condition);
1388
1389                 $param_string = self::buildParameter($params);
1390
1391                 $sql = "SELECT " . $select_fields . " FROM `" . $table . "`" . $condition_string . $param_string;
1392
1393                 $result = self::p($sql, $condition);
1394
1395                 return $result;
1396         }
1397
1398         /**
1399          * @brief Counts the rows from a table satisfying the provided condition
1400          *
1401          * @param string $table     Table name
1402          * @param array  $condition array of fields for condition
1403          *
1404          * @return int
1405          *
1406          * Example:
1407          * $table = "item";
1408          *
1409          * $condition = ["uid" => 1, "network" => 'dspr'];
1410          * or:
1411          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1412          *
1413          * $count = DBA::count($table, $condition);
1414          * @throws \Exception
1415          */
1416         public static function count($table, array $condition = [])
1417         {
1418                 if ($table == '') {
1419                         return false;
1420                 }
1421
1422                 $condition_string = self::buildCondition($condition);
1423
1424                 $sql = "SELECT COUNT(*) AS `count` FROM `".$table."`".$condition_string;
1425
1426                 $row = self::fetchFirst($sql, $condition);
1427
1428                 return $row['count'];
1429         }
1430
1431         /**
1432          * @brief Returns the SQL condition string built from the provided condition array
1433          *
1434          * This function operates with two modes.
1435          * - Supplied with a filed/value associative array, it builds simple strict
1436          *   equality conditions linked by AND.
1437          * - Supplied with a flat list, the first element is the condition string and
1438          *   the following arguments are the values to be interpolated
1439          *
1440          * $condition = ["uid" => 1, "network" => 'dspr'];
1441          * or:
1442          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1443          *
1444          * In either case, the provided array is left with the parameters only
1445          *
1446          * @param array $condition
1447          * @return string
1448          */
1449         public static function buildCondition(array &$condition = [])
1450         {
1451                 $condition_string = '';
1452                 if (count($condition) > 0) {
1453                         reset($condition);
1454                         $first_key = key($condition);
1455                         if (is_int($first_key)) {
1456                                 $condition_string = " WHERE (" . array_shift($condition) . ")";
1457                         } else {
1458                                 $new_values = [];
1459                                 $condition_string = "";
1460                                 foreach ($condition as $field => $value) {
1461                                         if ($condition_string != "") {
1462                                                 $condition_string .= " AND ";
1463                                         }
1464                                         if (is_array($value)) {
1465                                                 /* Workaround for MySQL Bug #64791.
1466                                                  * Never mix data types inside any IN() condition.
1467                                                  * In case of mixed types, cast all as string.
1468                                                  * Logic needs to be consistent with DBA::p() data types.
1469                                                  */
1470                                                 $is_int = false;
1471                                                 $is_alpha = false;
1472                                                 foreach ($value as $single_value) {
1473                                                         if (is_int($single_value)) {
1474                                                                 $is_int = true;
1475                                                         } else {
1476                                                                 $is_alpha = true;
1477                                                         }
1478                                                 }
1479
1480                                                 if ($is_int && $is_alpha) {
1481                                                         foreach ($value as &$ref) {
1482                                                                 if (is_int($ref)) {
1483                                                                         $ref = (string)$ref;
1484                                                                 }
1485                                                         }
1486                                                         unset($ref); //Prevent accidental re-use.
1487                                                 }
1488
1489                                                 $new_values = array_merge($new_values, array_values($value));
1490                                                 $placeholders = substr(str_repeat("?, ", count($value)), 0, -2);
1491                                                 $condition_string .= "`" . $field . "` IN (" . $placeholders . ")";
1492                                         } else {
1493                                                 $new_values[$field] = $value;
1494                                                 $condition_string .= "`" . $field . "` = ?";
1495                                         }
1496                                 }
1497                                 $condition_string = " WHERE (" . $condition_string . ")";
1498                                 $condition = $new_values;
1499                         }
1500                 }
1501
1502                 return $condition_string;
1503         }
1504
1505         /**
1506          * @brief Returns the SQL parameter string built from the provided parameter array
1507          *
1508          * @param array $params
1509          * @return string
1510          */
1511         public static function buildParameter(array $params = [])
1512         {
1513                 $order_string = '';
1514                 if (isset($params['order'])) {
1515                         $order_string = " ORDER BY ";
1516                         foreach ($params['order'] AS $fields => $order) {
1517                                 if (!is_int($fields)) {
1518                                         $order_string .= "`" . $fields . "` " . ($order ? "DESC" : "ASC") . ", ";
1519                                 } else {
1520                                         $order_string .= "`" . $order . "`, ";
1521                                 }
1522                         }
1523                         $order_string = substr($order_string, 0, -2);
1524                 }
1525
1526                 $limit_string = '';
1527                 if (isset($params['limit']) && is_numeric($params['limit'])) {
1528                         $limit_string = " LIMIT " . intval($params['limit']);
1529                 }
1530
1531                 if (isset($params['limit']) && is_array($params['limit'])) {
1532                         $limit_string = " LIMIT " . intval($params['limit'][0]) . ", " . intval($params['limit'][1]);
1533                 }
1534
1535                 return $order_string.$limit_string;
1536         }
1537
1538         /**
1539          * @brief Fills an array with data from a query
1540          *
1541          * @param object $stmt statement object
1542          * @param bool   $do_close
1543          * @return array Data array
1544          */
1545         public static function toArray($stmt, $do_close = true) {
1546                 if (is_bool($stmt)) {
1547                         return $stmt;
1548                 }
1549
1550                 $data = [];
1551                 while ($row = self::fetch($stmt)) {
1552                         $data[] = $row;
1553                 }
1554                 if ($do_close) {
1555                         self::close($stmt);
1556                 }
1557                 return $data;
1558         }
1559
1560         /**
1561          * @brief Returns the error number of the last query
1562          *
1563          * @return string Error number (0 if no error)
1564          */
1565         public static function errorNo() {
1566                 return self::$errorno;
1567         }
1568
1569         /**
1570          * @brief Returns the error message of the last query
1571          *
1572          * @return string Error message ('' if no error)
1573          */
1574         public static function errorMessage() {
1575                 return self::$error;
1576         }
1577
1578         /**
1579          * @brief Closes the current statement
1580          *
1581          * @param object $stmt statement object
1582          * @return boolean was the close successful?
1583          */
1584         public static function close($stmt) {
1585
1586                 $stamp1 = microtime(true);
1587
1588                 if (!is_object($stmt)) {
1589                         return false;
1590                 }
1591
1592                 switch (self::$driver) {
1593                         case 'pdo':
1594                                 $ret = $stmt->closeCursor();
1595                                 break;
1596                         case 'mysqli':
1597                                 // MySQLi offers both a mysqli_stmt and a mysqli_result class.
1598                                 // We should be careful not to assume the object type of $stmt
1599                                 // because DBA::p() has been able to return both types.
1600                                 if ($stmt instanceof mysqli_stmt) {
1601                                         $stmt->free_result();
1602                                         $ret = $stmt->close();
1603                                 } elseif ($stmt instanceof mysqli_result) {
1604                                         $stmt->free();
1605                                         $ret = true;
1606                                 } else {
1607                                         $ret = false;
1608                                 }
1609                                 break;
1610                 }
1611
1612                 self::$profiler->saveTimestamp($stamp1, 'database', System::callstack());
1613
1614                 return $ret;
1615         }
1616
1617         /**
1618          * @brief Return a list of database processes
1619          *
1620          * @return array
1621          *      'list' => List of processes, separated in their different states
1622          *      'amount' => Number of concurrent database processes
1623          * @throws \Exception
1624          */
1625         public static function processlist()
1626         {
1627                 $ret = self::p("SHOW PROCESSLIST");
1628                 $data = self::toArray($ret);
1629
1630                 $processes = 0;
1631                 $states = [];
1632                 foreach ($data as $process) {
1633                         $state = trim($process["State"]);
1634
1635                         // Filter out all non blocking processes
1636                         if (!in_array($state, ["", "init", "statistics", "updating"])) {
1637                                 ++$states[$state];
1638                                 ++$processes;
1639                         }
1640                 }
1641
1642                 $statelist = "";
1643                 foreach ($states as $state => $usage) {
1644                         if ($statelist != "") {
1645                                 $statelist .= ", ";
1646                         }
1647                         $statelist .= $state.": ".$usage;
1648                 }
1649                 return(["list" => $statelist, "amount" => $processes]);
1650         }
1651
1652         /**
1653          * Checks if $array is a filled array with at least one entry.
1654          *
1655          * @param mixed $array A filled array with at least one entry
1656          *
1657          * @return boolean Whether $array is a filled array or an object with rows
1658          */
1659         public static function isResult($array)
1660         {
1661                 // It could be a return value from an update statement
1662                 if (is_bool($array)) {
1663                         return $array;
1664                 }
1665
1666                 if (is_object($array)) {
1667                         return self::numRows($array) > 0;
1668                 }
1669
1670                 return (is_array($array) && (count($array) > 0));
1671         }
1672
1673         /**
1674          * @brief Callback function for "esc_array"
1675          *
1676          * @param mixed   $value         Array value
1677          * @param string  $key           Array key
1678          * @param boolean $add_quotation add quotation marks for string values
1679          * @return void
1680          */
1681         private static function escapeArrayCallback(&$value, $key, $add_quotation)
1682         {
1683                 if (!$add_quotation) {
1684                         if (is_bool($value)) {
1685                                 $value = ($value ? '1' : '0');
1686                         } else {
1687                                 $value = self::escape($value);
1688                         }
1689                         return;
1690                 }
1691
1692                 if (is_bool($value)) {
1693                         $value = ($value ? 'true' : 'false');
1694                 } elseif (is_float($value) || is_integer($value)) {
1695                         $value = (string) $value;
1696                 } else {
1697                         $value = "'" . self::escape($value) . "'";
1698                 }
1699         }
1700
1701         /**
1702          * @brief Escapes a whole array
1703          *
1704          * @param mixed   $arr           Array with values to be escaped
1705          * @param boolean $add_quotation add quotation marks for string values
1706          * @return void
1707          */
1708         public static function escapeArray(&$arr, $add_quotation = false)
1709         {
1710                 array_walk($arr, 'self::escapeArrayCallback', $add_quotation);
1711         }
1712 }