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         private static $server_info = '';
  48         /** @var PDO|mysqli */
  49         private static $connection;
  50         private static $driver;
  51         private static $error = false;
  52         private static $errorno = 0;
  53         private static $affected_rows = 0;
  54         private static $in_transaction = false;
  55         private static $in_retrial = false;
  56         private static $relation = [];
  57         private static $db_serveraddr = '';
  58         private static $db_user = '';
  59         private static $db_pass = '';
  60         private static $db_name = '';
  61         private static $db_charset = '';
  62
  63         public static function connect(IConfigCache $configCache, Profiler $profiler, LoggerInterface $logger, $serveraddr, $user, $pass, $db, $charset = null)
  64         {
  65                 if (!is_null(self::$connection) && self::connected()) {
  66                         return true;
  67                 }
  68
  69                 // We are storing these values for being able to perform a reconnect
  70                 self::$configCache = $configCache;
  71                 self::$profiler = $profiler;
  72                 self::$logger = $logger;
  73                 self::$db_serveraddr = $serveraddr;
  74                 self::$db_user = $user;
  75                 self::$db_pass = $pass;
  76                 self::$db_name = $db;
  77                 self::$db_charset = $charset;
  78
  79                 $port = 0;
  80                 $serveraddr = trim($serveraddr);
  81
  82                 $serverdata = explode(':', $serveraddr);
  83                 $server = $serverdata[0];
  84
  85                 if (count($serverdata) > 1) {
  86                         $port = trim($serverdata[1]);
  87                 }
  88
  89                 $server = trim($server);
  90                 $user = trim($user);
  91                 $pass = trim($pass);
  92                 $db = trim($db);
  93                 $charset = trim($charset);
  94
  95                 if (!(strlen($server) && strlen($user))) {
  96                         return false;
  97                 }
  98
  99                 if (class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
 100                         self::$driver = 'pdo';
 101                         $connect = "mysql:host=".$server.";dbname=".$db;
 102
 103                         if ($port > 0) {
 104                                 $connect .= ";port=".$port;
 105                         }
 106
 107                         if ($charset) {
 108                                 $connect .= ";charset=".$charset;
 109                         }
 110
 111                         try {
 112                                 self::$connection = @new PDO($connect, $user, $pass);
 113                                 self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
 114                                 self::$connected = true;
 115                         } catch (PDOException $e) {
 116                                 /// @TODO At least log exception, don't ignore it!
 117                         }
 118                 }
 119
 120                 if (!self::$connected && class_exists('\mysqli')) {
 121                         self::$driver = 'mysqli';
 122
 123                         if ($port > 0) {
 124                                 self::$connection = @new mysqli($server, $user, $pass, $db, $port);
 125                         } else {
 126                                 self::$connection = @new mysqli($server, $user, $pass, $db);
 127                         }
 128
 129                         if (!mysqli_connect_errno()) {
 130                                 self::$connected = true;
 131
 132                                 if ($charset) {
 133                                         self::$connection->set_charset($charset);
 134                                 }
 135                         }
 136                 }
 137
 138                 // No suitable SQL driver was found.
 139                 if (!self::$connected) {
 140                         self::$driver = null;
 141                         self::$connection = null;
 142                 }
 143
 144                 return self::$connected;
 145         }
 146
 147         /**
 148          * Sets the logger for DBA
 149          *
 150          * @note this is necessary because if we want to load the logger configuration
 151          *       from the DB, but there's an error, we would print out an exception.
 152          *       So the logger gets updated after the logger configuration can be retrieved
 153          *       from the database
 154          *
 155          * @param LoggerInterface $logger
 156          */
 157         public static function setLogger(LoggerInterface $logger)
 158         {
 159                 self::$logger = $logger;
 160         }
 161
 162         /**
 163          * Disconnects the current database connection
 164          */
 165         public static function disconnect()
 166         {
 167                 if (is_null(self::$connection)) {
 168                         return;
 169                 }
 170
 171                 switch (self::$driver) {
 172                         case 'pdo':
 173                                 self::$connection = null;
 174                                 break;
 175                         case 'mysqli':
 176                                 self::$connection->close();
 177                                 self::$connection = null;
 178                                 break;
 179                 }
 180         }
 181
 182         /**
 183          * Perform a reconnect of an existing database connection
 184          */
 185         public static function reconnect() {
 186                 self::disconnect();
 187
 188                 $ret = self::connect(self::$configCache, self::$profiler, self::$logger, self::$db_serveraddr, self::$db_user, self::$db_pass, self::$db_name, self::$db_charset);
 189                 return $ret;
 190         }
 191
 192         /**
 193          * Return the database object.
 194          * @return PDO|mysqli
 195          */
 196         public static function getConnection()
 197         {
 198                 return self::$connection;
 199         }
 200
 201         /**
 202          * @brief Returns the MySQL server version string
 203          *
 204          * This function discriminate between the deprecated mysql API and the current
 205          * object-oriented mysqli API. Example of returned string: 5.5.46-0+deb8u1
 206          *
 207          * @return string
 208          */
 209         public static function serverInfo() {
 210                 if (self::$server_info == '') {
 211                         switch (self::$driver) {
 212                                 case 'pdo':
 213                                         self::$server_info = self::$connection->getAttribute(PDO::ATTR_SERVER_VERSION);
 214                                         break;
 215                                 case 'mysqli':
 216                                         self::$server_info = self::$connection->server_info;
 217                                         break;
 218                         }
 219                 }
 220                 return self::$server_info;
 221         }
 222
 223         /**
 224          * @brief Returns the selected database name
 225          *
 226          * @return string
 227          * @throws \Exception
 228          */
 229         public static function databaseName() {
 230                 $ret = self::p("SELECT DATABASE() AS `db`");
 231                 $data = self::toArray($ret);
 232                 return $data[0]['db'];
 233         }
 234
 235         /**
 236          * @brief Analyze a database query and log this if some conditions are met.
 237          *
 238          * @param string $query The database query that will be analyzed
 239          * @throws \Exception
 240          */
 241         private static function logIndex($query) {
 242
 243                 if (!self::$configCache->get('system', 'db_log_index')) {
 244                         return;
 245                 }
 246
 247                 // Don't explain an explain statement
 248                 if (strtolower(substr($query, 0, 7)) == "explain") {
 249                         return;
 250                 }
 251
 252                 // Only do the explain on "select", "update" and "delete"
 253                 if (!in_array(strtolower(substr($query, 0, 6)), ["select", "update", "delete"])) {
 254                         return;
 255                 }
 256
 257                 $r = self::p("EXPLAIN ".$query);
 258                 if (!self::isResult($r)) {
 259                         return;
 260                 }
 261
 262                 $watchlist = explode(',', self::$configCache->get('system', 'db_log_index_watch'));
 263                 $blacklist = explode(',', self::$configCache->get('system', 'db_log_index_blacklist'));
 264
 265                 while ($row = self::fetch($r)) {
 266                         if ((intval(self::$configCache->get('system', 'db_loglimit_index')) > 0)) {
 267                                 $log = (in_array($row['key'], $watchlist) &&
 268                                         ($row['rows'] >= intval(self::$configCache->get('system', 'db_loglimit_index'))));
 269                         } else {
 270                                 $log = false;
 271                         }
 272
 273                         if ((intval(self::$configCache->get('system', 'db_loglimit_index_high')) > 0) && ($row['rows'] >= intval(self::$configCache->get('system', 'db_loglimit_index_high')))) {
 274                                 $log = true;
 275                         }
 276
 277                         if (in_array($row['key'], $blacklist) || ($row['key'] == "")) {
 278                                 $log = false;
 279                         }
 280
 281                         if ($log) {
 282                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 283                                 @file_put_contents(self::$configCache->get('system', 'db_log_index'), DateTimeFormat::utcNow()."\t".
 284                                                 $row['key']."\t".$row['rows']."\t".$row['Extra']."\t".
 285                                                 basename($backtrace[1]["file"])."\t".
 286                                                 $backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
 287                                                 substr($query, 0, 2000)."\n", FILE_APPEND);
 288                         }
 289                 }
 290         }
 291
 292         /**
 293          * Removes every not whitelisted character from the identifier string
 294          *
 295          * @param string $identifier
 296          *
 297          * @return string sanitized identifier
 298          * @throws \Exception
 299          */
 300         private static function sanitizeIdentifier($identifier)
 301         {
 302                 return preg_replace('/[^A-Za-z0-9_\-]+/', '', $identifier);
 303         }
 304
 305         public static function escape($str) {
 306                 if (self::$connected) {
 307                         switch (self::$driver) {
 308                                 case 'pdo':
 309                                         return substr(@self::$connection->quote($str, PDO::PARAM_STR), 1, -1);
 310
 311                                 case 'mysqli':
 312                                         return @self::$connection->real_escape_string($str);
 313                         }
 314                 } else {
 315                         return str_replace("'", "\\'", $str);
 316                 }
 317         }
 318
 319         public static function connected() {
 320                 $connected = false;
 321
 322                 if (is_null(self::$connection)) {
 323                         return false;
 324                 }
 325
 326                 switch (self::$driver) {
 327                         case 'pdo':
 328                                 $r = self::p("SELECT 1");
 329                                 if (self::isResult($r)) {
 330                                         $row = self::toArray($r);
 331                                         $connected = ($row[0]['1'] == '1');
 332                                 }
 333                                 break;
 334                         case 'mysqli':
 335                                 $connected = self::$connection->ping();
 336                                 break;
 337                 }
 338                 return $connected;
 339         }
 340
 341         /**
 342          * @brief Replaces ANY_VALUE() function by MIN() function,
 343          *  if the database server does not support ANY_VALUE().
 344          *
 345          * Considerations for Standard SQL, or MySQL with ONLY_FULL_GROUP_BY (default since 5.7.5).
 346          * ANY_VALUE() is available from MySQL 5.7.5 https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html
 347          * A standard fall-back is to use MIN().
 348          *
 349          * @param string $sql An SQL string without the values
 350          * @return string The input SQL string modified if necessary.
 351          */
 352         public static function anyValueFallback($sql) {
 353                 $server_info = self::serverInfo();
 354                 if (version_compare($server_info, '5.7.5', '<') ||
 355                         (stripos($server_info, 'MariaDB') !== false)) {
 356                         $sql = str_ireplace('ANY_VALUE(', 'MIN(', $sql);
 357                 }
 358                 return $sql;
 359         }
 360
 361         /**
 362          * @brief beautifies the query - useful for "SHOW PROCESSLIST"
 363          *
 364          * This is safe when we bind the parameters later.
 365          * The parameter values aren't part of the SQL.
 366          *
 367          * @param string $sql An SQL string without the values
 368          * @return string The input SQL string modified if necessary.
 369          */
 370         public static function cleanQuery($sql) {
 371                 $search = ["\t", "\n", "\r", "  "];
 372                 $replace = [' ', ' ', ' ', ' '];
 373                 do {
 374                         $oldsql = $sql;
 375                         $sql = str_replace($search, $replace, $sql);
 376                 } while ($oldsql != $sql);
 377
 378                 return $sql;
 379         }
 380
 381
 382         /**
 383          * @brief Replaces the ? placeholders with the parameters in the $args array
 384          *
 385          * @param string $sql SQL query
 386          * @param array $args The parameters that are to replace the ? placeholders
 387          * @return string The replaced SQL query
 388          */
 389         private static function replaceParameters($sql, $args) {
 390                 $offset = 0;
 391                 foreach ($args AS $param => $value) {
 392                         if (is_int($args[$param]) || is_float($args[$param])) {
 393                                 $replace = intval($args[$param]);
 394                         } else {
 395                                 $replace = "'".self::escape($args[$param])."'";
 396                         }
 397
 398                         $pos = strpos($sql, '?', $offset);
 399                         if ($pos !== false) {
 400                                 $sql = substr_replace($sql, $replace, $pos, 1);
 401                         }
 402                         $offset = $pos + strlen($replace);
 403                 }
 404                 return $sql;
 405         }
 406
 407         /**
 408          * @brief Convert parameter array to an universal form
 409          * @param array $args Parameter array
 410          * @return array universalized parameter array
 411          */
 412         private static function getParam($args) {
 413                 unset($args[0]);
 414
 415                 // When the second function parameter is an array then use this as the parameter array
 416                 if ((count($args) > 0) && (is_array($args[1]))) {
 417                         return $args[1];
 418                 } else {
 419                         return $args;
 420                 }
 421         }
 422
 423         /**
 424          * @brief Executes a prepared statement that returns data
 425          * @usage Example: $r = p("SELECT * FROM `item` WHERE `guid` = ?", $guid);
 426          *
 427          * Please only use it with complicated queries.
 428          * For all regular queries please use DBA::select or DBA::exists
 429          *
 430          * @param string $sql SQL statement
 431          * @return bool|object statement object or result object
 432          * @throws \Exception
 433          */
 434         public static function p($sql) {
 435
 436                 $stamp1 = microtime(true);
 437
 438                 $params = self::getParam(func_get_args());
 439
 440                 // Renumber the array keys to be sure that they fit
 441                 $i = 0;
 442                 $args = [];
 443                 foreach ($params AS $param) {
 444                         // Avoid problems with some MySQL servers and boolean values. See issue #3645
 445                         if (is_bool($param)) {
 446                                 $param = (int)$param;
 447                         }
 448                         $args[++$i] = $param;
 449                 }
 450
 451                 if (!self::$connected) {
 452                         return false;
 453                 }
 454
 455                 if ((substr_count($sql, '?') != count($args)) && (count($args) > 0)) {
 456                         // Question: Should we continue or stop the query here?
 457                         self::$logger->warning('Query parameters mismatch.', ['query' => $sql, 'args' => $args, 'callstack' => System::callstack()]);
 458                 }
 459
 460                 $sql = self::cleanQuery($sql);
 461                 $sql = self::anyValueFallback($sql);
 462
 463                 $orig_sql = $sql;
 464
 465                 if (self::$configCache->get('system', 'db_callstack') !== null) {
 466                         $sql = "/*".System::callstack()." */ ".$sql;
 467                 }
 468
 469                 self::$error = '';
 470                 self::$errorno = 0;
 471                 self::$affected_rows = 0;
 472
 473                 // We have to make some things different if this function is called from "e"
 474                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
 475
 476                 if (isset($trace[1])) {
 477                         $called_from = $trace[1];
 478                 } else {
 479                         // We use just something that is defined to avoid warnings
 480                         $called_from = $trace[0];
 481                 }
 482                 // We are having an own error logging in the function "e"
 483                 $called_from_e = ($called_from['function'] == 'e');
 484
 485                 switch (self::$driver) {
 486                         case 'pdo':
 487                                 // If there are no arguments we use "query"
 488                                 if (count($args) == 0) {
 489                                         if (!$retval = self::$connection->query($sql)) {
 490                                                 $errorInfo = self::$connection->errorInfo();
 491                                                 self::$error = $errorInfo[2];
 492                                                 self::$errorno = $errorInfo[1];
 493                                                 $retval = false;
 494                                                 break;
 495                                         }
 496                                         self::$affected_rows = $retval->rowCount();
 497                                         break;
 498                                 }
 499
 500                                 /** @var $stmt mysqli_stmt|PDOStatement */
 501                                 if (!$stmt = self::$connection->prepare($sql)) {
 502                                         $errorInfo = self::$connection->errorInfo();
 503                                         self::$error = $errorInfo[2];
 504                                         self::$errorno = $errorInfo[1];
 505                                         $retval = false;
 506                                         break;
 507                                 }
 508
 509                                 foreach ($args AS $param => $value) {
 510                                         if (is_int($args[$param])) {
 511                                                 $data_type = PDO::PARAM_INT;
 512                                         } else {
 513                                                 $data_type = PDO::PARAM_STR;
 514                                         }
 515                                         $stmt->bindParam($param, $args[$param], $data_type);
 516                                 }
 517
 518                                 if (!$stmt->execute()) {
 519                                         $errorInfo = $stmt->errorInfo();
 520                                         self::$error = $errorInfo[2];
 521                                         self::$errorno = $errorInfo[1];
 522                                         $retval = false;
 523                                 } else {
 524                                         $retval = $stmt;
 525                                         self::$affected_rows = $retval->rowCount();
 526                                 }
 527                                 break;
 528                         case 'mysqli':
 529                                 // There are SQL statements that cannot be executed with a prepared statement
 530                                 $parts = explode(' ', $orig_sql);
 531                                 $command = strtolower($parts[0]);
 532                                 $can_be_prepared = in_array($command, ['select', 'update', 'insert', 'delete']);
 533
 534                                 // The fallback routine is called as well when there are no arguments
 535                                 if (!$can_be_prepared || (count($args) == 0)) {
 536                                         $retval = self::$connection->query(self::replaceParameters($sql, $args));
 537                                         if (self::$connection->errno) {
 538                                                 self::$error = self::$connection->error;
 539                                                 self::$errorno = self::$connection->errno;
 540                                                 $retval = false;
 541                                         } else {
 542                                                 if (isset($retval->num_rows)) {
 543                                                         self::$affected_rows = $retval->num_rows;
 544                                                 } else {
 545                                                         self::$affected_rows = self::$connection->affected_rows;
 546                                                 }
 547                                         }
 548                                         break;
 549                                 }
 550
 551                                 $stmt = self::$connection->stmt_init();
 552
 553                                 if (!$stmt->prepare($sql)) {
 554                                         self::$error = $stmt->error;
 555                                         self::$errorno = $stmt->errno;
 556                                         $retval = false;
 557                                         break;
 558                                 }
 559
 560                                 $param_types = '';
 561                                 $values = [];
 562                                 foreach ($args AS $param => $value) {
 563                                         if (is_int($args[$param])) {
 564                                                 $param_types .= 'i';
 565                                         } elseif (is_float($args[$param])) {
 566                                                 $param_types .= 'd';
 567                                         } elseif (is_string($args[$param])) {
 568                                                 $param_types .= 's';
 569                                         } else {
 570                                                 $param_types .= 'b';
 571                                         }
 572                                         $values[] = &$args[$param];
 573                                 }
 574
 575                                 if (count($values) > 0) {
 576                                         array_unshift($values, $param_types);
 577                                         call_user_func_array([$stmt, 'bind_param'], $values);
 578                                 }
 579
 580                                 if (!$stmt->execute()) {
 581                                         self::$error = self::$connection->error;
 582                                         self::$errorno = self::$connection->errno;
 583                                         $retval = false;
 584                                 } else {
 585                                         $stmt->store_result();
 586                                         $retval = $stmt;
 587                                         self::$affected_rows = $retval->affected_rows;
 588                                 }
 589                                 break;
 590                 }
 591
 592                 // We are having an own error logging in the function "e"
 593                 if ((self::$errorno != 0) && !$called_from_e) {
 594                         // We have to preserve the error code, somewhere in the logging it get lost
 595                         $error = self::$error;
 596                         $errorno = self::$errorno;
 597
 598                         self::$logger->error('DB Error', [
 599                                 'code'      => self::$errorno,
 600                                 'error'     => self::$error,
 601                                 'callstack' => System::callstack(8),
 602                                 'params'    => self::replaceParameters($sql, $args),
 603                         ]);
 604
 605                         // On a lost connection we try to reconnect - but only once.
 606                         if ($errorno == 2006) {
 607                                 if (self::$in_retrial || !self::reconnect()) {
 608                                         // It doesn't make sense to continue when the database connection was lost
 609                                         if (self::$in_retrial) {
 610                                                 self::$logger->notice('Giving up retrial because of database error', [
 611                                                         'code'  => self::$errorno,
 612                                                         'error' => self::$error,
 613                                                 ]);
 614                                         } else {
 615                                                 self::$logger->notice('Couldn\'t reconnect after database error', [
 616                                                         'code'  => self::$errorno,
 617                                                         'error' => self::$error,
 618                                                 ]);
 619                                         }
 620                                         exit(1);
 621                                 } else {
 622                                         // We try it again
 623                                         self::$logger->notice('Reconnected after database error', [
 624                                                 'code'  => self::$errorno,
 625                                                 'error' => self::$error,
 626                                         ]);
 627                                         self::$in_retrial = true;
 628                                         $ret = self::p($sql, $args);
 629                                         self::$in_retrial = false;
 630                                         return $ret;
 631                                 }
 632                         }
 633
 634                         self::$error = $error;
 635                         self::$errorno = $errorno;
 636                 }
 637
 638                 self::$profiler->saveTimestamp($stamp1, 'database', System::callstack());
 639
 640                 if (self::$configCache->get('system', 'db_log')) {
 641                         $stamp2 = microtime(true);
 642                         $duration = (float)($stamp2 - $stamp1);
 643
 644                         if (($duration > self::$configCache->get('system', 'db_loglimit'))) {
 645                                 $duration = round($duration, 3);
 646                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 647
 648                                 @file_put_contents(self::$configCache->get('system', 'db_log'), DateTimeFormat::utcNow()."\t".$duration."\t".
 649                                                 basename($backtrace[1]["file"])."\t".
 650                                                 $backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
 651                                                 substr(self::replaceParameters($sql, $args), 0, 2000)."\n", FILE_APPEND);
 652                         }
 653                 }
 654                 return $retval;
 655         }
 656
 657         /**
 658          * @brief Executes a prepared statement like UPDATE or INSERT that doesn't return data
 659          *
 660          * Please use DBA::delete, DBA::insert, DBA::update, ... instead
 661          *
 662          * @param string $sql SQL statement
 663          * @return boolean Was the query successfull? False is returned only if an error occurred
 664          * @throws \Exception
 665          */
 666         public static function e($sql) {
 667
 668                 $stamp = microtime(true);
 669
 670                 $params = self::getParam(func_get_args());
 671
 672                 // In a case of a deadlock we are repeating the query 20 times
 673                 $timeout = 20;
 674
 675                 do {
 676                         $stmt = self::p($sql, $params);
 677
 678                         if (is_bool($stmt)) {
 679                                 $retval = $stmt;
 680                         } elseif (is_object($stmt)) {
 681                                 $retval = true;
 682                         } else {
 683                                 $retval = false;
 684                         }
 685
 686                         self::close($stmt);
 687
 688                 } while ((self::$errorno == 1213) && (--$timeout > 0));
 689
 690                 if (self::$errorno != 0) {
 691                         // We have to preserve the error code, somewhere in the logging it get lost
 692                         $error = self::$error;
 693                         $errorno = self::$errorno;
 694
 695                         self::$logger->error('DB Error', [
 696                                 'code'      => self::$errorno,
 697                                 'error'     => self::$error,
 698                                 'callstack' => System::callstack(8),
 699                                 'params'    => self::replaceParameters($sql, $params),
 700                         ]);
 701
 702                         // On a lost connection we simply quit.
 703                         // A reconnect like in self::p could be dangerous with modifications
 704                         if ($errorno == 2006) {
 705                                 self::$logger->notice('Giving up because of database error', [
 706                                         'code'  => self::$errorno,
 707                                         'error' => self::$error,
 708                                 ]);
 709                                 exit(1);
 710                         }
 711
 712                         self::$error = $error;
 713                         self::$errorno = $errorno;
 714                 }
 715
 716                 self::$profiler->saveTimestamp($stamp, "database_write", System::callstack());
 717
 718                 return $retval;
 719         }
 720
 721         /**
 722          * @brief Check if data exists
 723          *
 724          * @param string $table     Table name
 725          * @param array  $condition array of fields for condition
 726          *
 727          * @return boolean Are there rows for that condition?
 728          * @throws \Exception
 729          */
 730         public static function exists($table, $condition) {
 731                 if (empty($table)) {
 732                         return false;
 733                 }
 734
 735                 $fields = [];
 736
 737                 if (empty($condition)) {
 738                         return DBStructure::existsTable($table);
 739                 }
 740
 741                 reset($condition);
 742                 $first_key = key($condition);
 743                 if (!is_int($first_key)) {
 744                         $fields = [$first_key];
 745                 }
 746
 747                 $stmt = self::select($table, $fields, $condition, ['limit' => 1]);
 748
 749                 if (is_bool($stmt)) {
 750                         $retval = $stmt;
 751                 } else {
 752                         $retval = (self::numRows($stmt) > 0);
 753                 }
 754
 755                 self::close($stmt);
 756
 757                 return $retval;
 758         }
 759
 760         /**
 761          * Fetches the first row
 762          *
 763          * Please use DBA::selectFirst or DBA::exists whenever this is possible.
 764          *
 765          * @brief Fetches the first row
 766          * @param string $sql SQL statement
 767          * @return array first row of query
 768          * @throws \Exception
 769          */
 770         public static function fetchFirst($sql) {
 771                 $params = self::getParam(func_get_args());
 772
 773                 $stmt = self::p($sql, $params);
 774
 775                 if (is_bool($stmt)) {
 776                         $retval = $stmt;
 777                 } else {
 778                         $retval = self::fetch($stmt);
 779                 }
 780
 781                 self::close($stmt);
 782
 783                 return $retval;
 784         }
 785
 786         /**
 787          * @brief Returns the number of affected rows of the last statement
 788          *
 789          * @return int Number of rows
 790          */
 791         public static function affectedRows() {
 792                 return self::$affected_rows;
 793         }
 794
 795         /**
 796          * @brief Returns the number of columns of a statement
 797          *
 798          * @param object Statement object
 799          * @return int Number of columns
 800          */
 801         public static function columnCount($stmt) {
 802                 if (!is_object($stmt)) {
 803                         return 0;
 804                 }
 805                 switch (self::$driver) {
 806                         case 'pdo':
 807                                 return $stmt->columnCount();
 808                         case 'mysqli':
 809                                 return $stmt->field_count;
 810                 }
 811                 return 0;
 812         }
 813         /**
 814          * @brief Returns the number of rows of a statement
 815          *
 816          * @param PDOStatement|mysqli_result|mysqli_stmt Statement object
 817          * @return int Number of rows
 818          */
 819         public static function numRows($stmt) {
 820                 if (!is_object($stmt)) {
 821                         return 0;
 822                 }
 823                 switch (self::$driver) {
 824                         case 'pdo':
 825                                 return $stmt->rowCount();
 826                         case 'mysqli':
 827                                 return $stmt->num_rows;
 828                 }
 829                 return 0;
 830         }
 831
 832         /**
 833          * @brief Fetch a single row
 834          *
 835          * @param mixed $stmt statement object
 836          * @return array current row
 837          */
 838         public static function fetch($stmt) {
 839
 840                 $stamp1 = microtime(true);
 841
 842                 $columns = [];
 843
 844                 if (!is_object($stmt)) {
 845                         return false;
 846                 }
 847
 848                 switch (self::$driver) {
 849                         case 'pdo':
 850                                 $columns = $stmt->fetch(PDO::FETCH_ASSOC);
 851                                 break;
 852                         case 'mysqli':
 853                                 if (get_class($stmt) == 'mysqli_result') {
 854                                         $columns = $stmt->fetch_assoc();
 855                                         break;
 856                                 }
 857
 858                                 // This code works, but is slow
 859
 860                                 // Bind the result to a result array
 861                                 $cols = [];
 862
 863                                 $cols_num = [];
 864                                 for ($x = 0; $x < $stmt->field_count; $x++) {
 865                                         $cols[] = &$cols_num[$x];
 866                                 }
 867
 868                                 call_user_func_array([$stmt, 'bind_result'], $cols);
 869
 870                                 if (!$stmt->fetch()) {
 871                                         return false;
 872                                 }
 873
 874                                 // The slow part:
 875                                 // We need to get the field names for the array keys
 876                                 // It seems that there is no better way to do this.
 877                                 $result = $stmt->result_metadata();
 878                                 $fields = $result->fetch_fields();
 879
 880                                 foreach ($cols_num AS $param => $col) {
 881                                         $columns[$fields[$param]->name] = $col;
 882                                 }
 883                 }
 884
 885                 self::$profiler->saveTimestamp($stamp1, 'database', System::callstack());
 886
 887                 return $columns;
 888         }
 889
 890         /**
 891          * @brief Insert a row into a table
 892          *
 893          * @param string/array $table Table name
 894          *
 895          * @return string formatted and sanitzed table name
 896          * @throws \Exception
 897          */
 898         public static function formatTableName($table)
 899         {
 900                 if (is_string($table)) {
 901                         return "`" . self::sanitizeIdentifier($table) . "`";
 902                 }
 903
 904                 if (!is_array($table)) {
 905                         return '';
 906                 }
 907
 908                 $scheme = key($table);
 909
 910                 return "`" . self::sanitizeIdentifier($scheme) . "`.`" . self::sanitizeIdentifier($table[$scheme]) . "`";
 911         }
 912
 913         /**
 914          * @brief Insert a row into a table
 915          *
 916          * @param string $table               Table name
 917          * @param array  $param               parameter array
 918          * @param bool   $on_duplicate_update Do an update on a duplicate entry
 919          *
 920          * @return boolean was the insert successful?
 921          * @throws \Exception
 922          */
 923         public static function insert($table, $param, $on_duplicate_update = false) {
 924
 925                 if (empty($table) || empty($param)) {
 926                         self::$logger->info('Table and fields have to be set');
 927                         return false;
 928                 }
 929
 930                 $sql = "INSERT INTO " . self::formatTableName($table) . " (`".implode("`, `", array_keys($param))."`) VALUES (".
 931                         substr(str_repeat("?, ", count($param)), 0, -2).")";
 932
 933                 if ($on_duplicate_update) {
 934                         $sql .= " ON DUPLICATE KEY UPDATE `".implode("` = ?, `", array_keys($param))."` = ?";
 935
 936                         $values = array_values($param);
 937                         $param = array_merge_recursive($values, $values);
 938                 }
 939
 940                 return self::e($sql, $param);
 941         }
 942
 943         /**
 944          * @brief Fetch the id of the last insert command
 945          *
 946          * @return integer Last inserted id
 947          */
 948         public static function lastInsertId() {
 949                 switch (self::$driver) {
 950                         case 'pdo':
 951                                 $id = self::$connection->lastInsertId();
 952                                 break;
 953                         case 'mysqli':
 954                                 $id = self::$connection->insert_id;
 955                                 break;
 956                 }
 957                 return $id;
 958         }
 959
 960         /**
 961          * @brief Locks a table for exclusive write access
 962          *
 963          * This function can be extended in the future to accept a table array as well.
 964          *
 965          * @param string $table Table name
 966          *
 967          * @return boolean was the lock successful?
 968          * @throws \Exception
 969          */
 970         public static function lock($table) {
 971                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
 972                 if (self::$driver == 'pdo') {
 973                         self::e("SET autocommit=0");
 974                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
 975                 } else {
 976                         self::$connection->autocommit(false);
 977                 }
 978
 979                 $success = self::e("LOCK TABLES " . self::formatTableName($table) ." WRITE");
 980
 981                 if (self::$driver == 'pdo') {
 982                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
 983                 }
 984
 985                 if (!$success) {
 986                         if (self::$driver == 'pdo') {
 987                                 self::e("SET autocommit=1");
 988                         } else {
 989                                 self::$connection->autocommit(true);
 990                         }
 991                 } else {
 992                         self::$in_transaction = true;
 993                 }
 994                 return $success;
 995         }
 996
 997         /**
 998          * @brief Unlocks all locked tables
 999          *
1000          * @return boolean was the unlock successful?
1001          * @throws \Exception
1002          */
1003         public static function unlock() {
1004                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1005                 self::performCommit();
1006
1007                 if (self::$driver == 'pdo') {
1008                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1009                 }
1010
1011                 $success = self::e("UNLOCK TABLES");
1012
1013                 if (self::$driver == 'pdo') {
1014                         self::$connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
1015                         self::e("SET autocommit=1");
1016                 } else {
1017                         self::$connection->autocommit(true);
1018                 }
1019
1020                 self::$in_transaction = false;
1021                 return $success;
1022         }
1023
1024         /**
1025          * @brief Starts a transaction
1026          *
1027          * @return boolean Was the command executed successfully?
1028          */
1029         public static function transaction() {
1030                 if (!self::performCommit()) {
1031                         return false;
1032                 }
1033
1034                 switch (self::$driver) {
1035                         case 'pdo':
1036                                 if (!self::$connection->inTransaction() && !self::$connection->beginTransaction()) {
1037                                         return false;
1038                                 }
1039                                 break;
1040
1041                         case 'mysqli':
1042                                 if (!self::$connection->begin_transaction()) {
1043                                         return false;
1044                                 }
1045                                 break;
1046                 }
1047
1048                 self::$in_transaction = true;
1049                 return true;
1050         }
1051
1052         private static function performCommit()
1053         {
1054                 switch (self::$driver) {
1055                         case 'pdo':
1056                                 if (!self::$connection->inTransaction()) {
1057                                         return true;
1058                                 }
1059
1060                                 return self::$connection->commit();
1061
1062                         case 'mysqli':
1063                                 return self::$connection->commit();
1064                 }
1065
1066                 return true;
1067         }
1068
1069         /**
1070          * @brief Does a commit
1071          *
1072          * @return boolean Was the command executed successfully?
1073          */
1074         public static function commit() {
1075                 if (!self::performCommit()) {
1076                         return false;
1077                 }
1078                 self::$in_transaction = false;
1079                 return true;
1080         }
1081
1082         /**
1083          * @brief Does a rollback
1084          *
1085          * @return boolean Was the command executed successfully?
1086          */
1087         public static function rollback() {
1088                 $ret = false;
1089
1090                 switch (self::$driver) {
1091                         case 'pdo':
1092                                 if (!self::$connection->inTransaction()) {
1093                                         $ret = true;
1094                                         break;
1095                                 }
1096                                 $ret = self::$connection->rollBack();
1097                                 break;
1098
1099                         case 'mysqli':
1100                                 $ret = self::$connection->rollback();
1101                                 break;
1102                 }
1103                 self::$in_transaction = false;
1104                 return $ret;
1105         }
1106
1107         /**
1108          * @brief Build the array with the table relations
1109          *
1110          * The array is build from the database definitions in DBStructure.php
1111          *
1112          * This process must only be started once, since the value is cached.
1113          */
1114         private static function buildRelationData() {
1115                 $definition = DBStructure::definition(self::$configCache->get('system', 'basepath'));
1116
1117                 foreach ($definition AS $table => $structure) {
1118                         foreach ($structure['fields'] AS $field => $field_struct) {
1119                                 if (isset($field_struct['relation'])) {
1120                                         foreach ($field_struct['relation'] AS $rel_table => $rel_field) {
1121                                                 self::$relation[$rel_table][$rel_field][$table][] = $field;
1122                                         }
1123                                 }
1124                         }
1125                 }
1126         }
1127
1128         /**
1129          * @brief Delete a row from a table
1130          *
1131          * @param string $table      Table name
1132          * @param array  $conditions Field condition(s)
1133          * @param array  $options
1134          *                           - cascade: If true we delete records in other tables that depend on the one we're deleting through
1135          *                           relations (default: true)
1136          * @param array  $callstack  Internal use: prevent endless loops
1137          *
1138          * @return boolean was the delete successful?
1139          * @throws \Exception
1140          */
1141         public static function delete($table, array $conditions, array $options = [], array &$callstack = [])
1142         {
1143                 if (empty($table) || empty($conditions)) {
1144                         self::$logger->info('Table and conditions have to be set');
1145                         return false;
1146                 }
1147
1148                 $commands = [];
1149
1150                 // Create a key for the loop prevention
1151                 $key = $table . ':' . json_encode($conditions);
1152
1153                 // We quit when this key already exists in the callstack.
1154                 if (isset($callstack[$key])) {
1155                         return $commands;
1156                 }
1157
1158                 $callstack[$key] = true;
1159
1160                 $table = self::sanitizeIdentifier($table);
1161
1162                 $commands[$key] = ['table' => $table, 'conditions' => $conditions];
1163
1164                 // Don't use "defaults" here, since it would set "false" to "true"
1165                 if (isset($options['cascade'])) {
1166                         $cascade = $options['cascade'];
1167                 } else {
1168                         $cascade = true;
1169                 }
1170
1171                 // To speed up the whole process we cache the table relations
1172                 if ($cascade && count(self::$relation) == 0) {
1173                         self::buildRelationData();
1174                 }
1175
1176                 // Is there a relation entry for the table?
1177                 if ($cascade && isset(self::$relation[$table])) {
1178                         // We only allow a simple "one field" relation.
1179                         $field = array_keys(self::$relation[$table])[0];
1180                         $rel_def = array_values(self::$relation[$table])[0];
1181
1182                         // Create a key for preventing double queries
1183                         $qkey = $field . '-' . $table . ':' . json_encode($conditions);
1184
1185                         // When the search field is the relation field, we don't need to fetch the rows
1186                         // This is useful when the leading record is already deleted in the frontend but the rest is done in the backend
1187                         if ((count($conditions) == 1) && ($field == array_keys($conditions)[0])) {
1188                                 foreach ($rel_def AS $rel_table => $rel_fields) {
1189                                         foreach ($rel_fields AS $rel_field) {
1190                                                 self::delete($rel_table, [$rel_field => array_values($conditions)[0]], $options, $callstack);
1191                                         }
1192                                 }
1193                                 // We quit when this key already exists in the callstack.
1194                         } elseif (!isset($callstack[$qkey])) {
1195                                 $callstack[$qkey] = true;
1196
1197                                 // Fetch all rows that are to be deleted
1198                                 $data = self::select($table, [$field], $conditions);
1199
1200                                 while ($row = self::fetch($data)) {
1201                                         self::delete($table, [$field => $row[$field]], $options, $callstack);
1202                                 }
1203
1204                                 self::close($data);
1205
1206                                 // Since we had split the delete command we don't need the original command anymore
1207                                 unset($commands[$key]);
1208                         }
1209                 }
1210
1211                 // Now we finalize the process
1212                 $do_transaction = !self::$in_transaction;
1213
1214                 if ($do_transaction) {
1215                         self::transaction();
1216                 }
1217
1218                 $compacted = [];
1219                 $counter = [];
1220
1221                 foreach ($commands AS $command) {
1222                         $conditions = $command['conditions'];
1223                         reset($conditions);
1224                         $first_key = key($conditions);
1225
1226                         $condition_string = self::buildCondition($conditions);
1227
1228                         if ((count($command['conditions']) > 1) || is_int($first_key)) {
1229                                 $sql = "DELETE FROM `" . $command['table'] . "`" . $condition_string;
1230                                 self::$logger->debug(self::replaceParameters($sql, $conditions));
1231
1232                                 if (!self::e($sql, $conditions)) {
1233                                         if ($do_transaction) {
1234                                                 self::rollback();
1235                                         }
1236                                         return false;
1237                                 }
1238                         } else {
1239                                 $key_table = $command['table'];
1240                                 $key_condition = array_keys($command['conditions'])[0];
1241                                 $value = array_values($command['conditions'])[0];
1242
1243                                 // Split the SQL queries in chunks of 100 values
1244                                 // We do the $i stuff here to make the code better readable
1245                                 $i = isset($counter[$key_table][$key_condition]) ? $counter[$key_table][$key_condition] : 0;
1246                                 if (isset($compacted[$key_table][$key_condition][$i]) && count($compacted[$key_table][$key_condition][$i]) > 100) {
1247                                         ++$i;
1248                                 }
1249
1250                                 $compacted[$key_table][$key_condition][$i][$value] = $value;
1251                                 $counter[$key_table][$key_condition] = $i;
1252                         }
1253                 }
1254                 foreach ($compacted AS $table => $values) {
1255                         foreach ($values AS $field => $field_value_list) {
1256                                 foreach ($field_value_list AS $field_values) {
1257                                         $sql = "DELETE FROM `" . $table . "` WHERE `" . $field . "` IN (" .
1258                                                 substr(str_repeat("?, ", count($field_values)), 0, -2) . ");";
1259
1260                                         self::$logger->debug(self::replaceParameters($sql, $field_values));
1261
1262                                         if (!self::e($sql, $field_values)) {
1263                                                 if ($do_transaction) {
1264                                                         self::rollback();
1265                                                 }
1266                                                 return false;
1267                                         }
1268                                 }
1269                         }
1270                 }
1271                 if ($do_transaction) {
1272                         self::commit();
1273                 }
1274                 return true;
1275         }
1276
1277         /**
1278          * @brief Updates rows
1279          *
1280          * Updates rows in the database. When $old_fields is set to an array,
1281          * the system will only do an update if the fields in that array changed.
1282          *
1283          * Attention:
1284          * Only the values in $old_fields are compared.
1285          * This is an intentional behaviour.
1286          *
1287          * Example:
1288          * We include the timestamp field in $fields but not in $old_fields.
1289          * Then the row will only get the new timestamp when the other fields had changed.
1290          *
1291          * When $old_fields is set to a boolean value the system will do this compare itself.
1292          * When $old_fields is set to "true" the system will do an insert if the row doesn't exists.
1293          *
1294          * Attention:
1295          * Only set $old_fields to a boolean value when you are sure that you will update a single row.
1296          * When you set $old_fields to "true" then $fields must contain all relevant fields!
1297          *
1298          * @param string        $table      Table name
1299          * @param array         $fields     contains the fields that are updated
1300          * @param array         $condition  condition array with the key values
1301          * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate)
1302          *
1303          * @return boolean was the update successfull?
1304          * @throws \Exception
1305          */
1306         public static function update($table, $fields, $condition, $old_fields = []) {
1307
1308                 if (empty($table) || empty($fields) || empty($condition)) {
1309                         self::$logger->info('Table, fields and condition have to be set');
1310                         return false;
1311                 }
1312
1313                 $condition_string = self::buildCondition($condition);
1314
1315                 if (is_bool($old_fields)) {
1316                         $do_insert = $old_fields;
1317
1318                         $old_fields = self::selectFirst($table, [], $condition);
1319
1320                         if (is_bool($old_fields)) {
1321                                 if ($do_insert) {
1322                                         $values = array_merge($condition, $fields);
1323                                         return self::insert($table, $values, $do_insert);
1324                                 }
1325                                 $old_fields = [];
1326                         }
1327                 }
1328
1329                 $do_update = (count($old_fields) == 0);
1330
1331                 foreach ($old_fields AS $fieldname => $content) {
1332                         if (isset($fields[$fieldname])) {
1333                                 if (($fields[$fieldname] == $content) && !is_null($content)) {
1334                                         unset($fields[$fieldname]);
1335                                 } else {
1336                                         $do_update = true;
1337                                 }
1338                         }
1339                 }
1340
1341                 if (!$do_update || (count($fields) == 0)) {
1342                         return true;
1343                 }
1344
1345                 $sql = "UPDATE ". self::formatTableName($table) . " SET `".
1346                         implode("` = ?, `", array_keys($fields))."` = ?".$condition_string;
1347
1348                 $params1 = array_values($fields);
1349                 $params2 = array_values($condition);
1350                 $params = array_merge_recursive($params1, $params2);
1351
1352                 return self::e($sql, $params);
1353         }
1354
1355         /**
1356          * Retrieve a single record from a table and returns it in an associative array
1357          *
1358          * @brief Retrieve a single record from a table
1359          * @param string $table
1360          * @param array  $fields
1361          * @param array  $condition
1362          * @param array  $params
1363          * @return bool|array
1364          * @throws \Exception
1365          * @see   self::select
1366          */
1367         public static function selectFirst($table, array $fields = [], array $condition = [], $params = [])
1368         {
1369                 $params['limit'] = 1;
1370                 $result = self::select($table, $fields, $condition, $params);
1371
1372                 if (is_bool($result)) {
1373                         return $result;
1374                 } else {
1375                         $row = self::fetch($result);
1376                         self::close($result);
1377                         return $row;
1378                 }
1379         }
1380
1381         /**
1382          * @brief Select rows from a table
1383          *
1384          * @param string $table     Table name
1385          * @param array  $fields    Array of selected fields, empty for all
1386          * @param array  $condition Array of fields for condition
1387          * @param array  $params    Array of several parameters
1388          *
1389          * @return boolean|object
1390          *
1391          * Example:
1392          * $table = "item";
1393          * $fields = array("id", "uri", "uid", "network");
1394          *
1395          * $condition = array("uid" => 1, "network" => 'dspr');
1396          * or:
1397          * $condition = array("`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr');
1398          *
1399          * $params = array("order" => array("id", "received" => true), "limit" => 10);
1400          *
1401          * $data = DBA::select($table, $fields, $condition, $params);
1402          * @throws \Exception
1403          */
1404         public static function select($table, array $fields = [], array $condition = [], array $params = [])
1405         {
1406                 if (empty($table)) {
1407                         return false;
1408                 }
1409
1410                 if (count($fields) > 0) {
1411                         $select_fields = "`" . implode("`, `", array_values($fields)) . "`";
1412                 } else {
1413                         $select_fields = "*";
1414                 }
1415
1416                 $condition_string = self::buildCondition($condition);
1417
1418                 $param_string = self::buildParameter($params);
1419
1420                 $sql = "SELECT " . $select_fields . " FROM " . self::formatTableName($table) . $condition_string . $param_string;
1421
1422                 $result = self::p($sql, $condition);
1423
1424                 return $result;
1425         }
1426
1427         /**
1428          * @brief Counts the rows from a table satisfying the provided condition
1429          *
1430          * @param string $table     Table name
1431          * @param array  $condition array of fields for condition
1432          *
1433          * @return int
1434          *
1435          * Example:
1436          * $table = "item";
1437          *
1438          * $condition = ["uid" => 1, "network" => 'dspr'];
1439          * or:
1440          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1441          *
1442          * $count = DBA::count($table, $condition);
1443          * @throws \Exception
1444          */
1445         public static function count($table, array $condition = [])
1446         {
1447                 if (empty($table)) {
1448                         return false;
1449                 }
1450
1451                 $condition_string = self::buildCondition($condition);
1452
1453                 $sql = "SELECT COUNT(*) AS `count` FROM " . self::formatTableName($table) . $condition_string;
1454
1455                 $row = self::fetchFirst($sql, $condition);
1456
1457                 return $row['count'];
1458         }
1459
1460         /**
1461          * @brief Returns the SQL condition string built from the provided condition array
1462          *
1463          * This function operates with two modes.
1464          * - Supplied with a filed/value associative array, it builds simple strict
1465          *   equality conditions linked by AND.
1466          * - Supplied with a flat list, the first element is the condition string and
1467          *   the following arguments are the values to be interpolated
1468          *
1469          * $condition = ["uid" => 1, "network" => 'dspr'];
1470          * or:
1471          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1472          *
1473          * In either case, the provided array is left with the parameters only
1474          *
1475          * @param array $condition
1476          * @return string
1477          */
1478         public static function buildCondition(array &$condition = [])
1479         {
1480                 $condition_string = '';
1481                 if (count($condition) > 0) {
1482                         reset($condition);
1483                         $first_key = key($condition);
1484                         if (is_int($first_key)) {
1485                                 $condition_string = " WHERE (" . array_shift($condition) . ")";
1486                         } else {
1487                                 $new_values = [];
1488                                 $condition_string = "";
1489                                 foreach ($condition as $field => $value) {
1490                                         if ($condition_string != "") {
1491                                                 $condition_string .= " AND ";
1492                                         }
1493                                         if (is_array($value)) {
1494                                                 /* Workaround for MySQL Bug #64791.
1495                                                  * Never mix data types inside any IN() condition.
1496                                                  * In case of mixed types, cast all as string.
1497                                                  * Logic needs to be consistent with DBA::p() data types.
1498                                                  */
1499                                                 $is_int = false;
1500                                                 $is_alpha = false;
1501                                                 foreach ($value as $single_value) {
1502                                                         if (is_int($single_value)) {
1503                                                                 $is_int = true;
1504                                                         } else {
1505                                                                 $is_alpha = true;
1506                                                         }
1507                                                 }
1508
1509                                                 if ($is_int && $is_alpha) {
1510                                                         foreach ($value as &$ref) {
1511                                                                 if (is_int($ref)) {
1512                                                                         $ref = (string)$ref;
1513                                                                 }
1514                                                         }
1515                                                         unset($ref); //Prevent accidental re-use.
1516                                                 }
1517
1518                                                 $new_values = array_merge($new_values, array_values($value));
1519                                                 $placeholders = substr(str_repeat("?, ", count($value)), 0, -2);
1520                                                 $condition_string .= "`" . $field . "` IN (" . $placeholders . ")";
1521                                         } elseif (is_null($value)) {
1522                                                 $condition_string .= "`" . $field . "` IS NULL";
1523                                         } else {
1524                                                 $new_values[$field] = $value;
1525                                                 $condition_string .= "`" . $field . "` = ?";
1526                                         }
1527                                 }
1528                                 $condition_string = " WHERE (" . $condition_string . ")";
1529                                 $condition = $new_values;
1530                         }
1531                 }
1532
1533                 return $condition_string;
1534         }
1535
1536         /**
1537          * @brief Returns the SQL parameter string built from the provided parameter array
1538          *
1539          * @param array $params
1540          * @return string
1541          */
1542         public static function buildParameter(array $params = [])
1543         {
1544                 $groupby_string = '';
1545                 if (isset($params['group_by'])) {
1546                         $groupby_string = " GROUP BY ";
1547                         foreach ($params['group_by'] as $fields) {
1548                                 $groupby_string .= "`" . $fields . "`, ";
1549                         }
1550                         $groupby_string = substr($groupby_string, 0, -2);
1551                 }
1552
1553                 $order_string = '';
1554                 if (isset($params['order'])) {
1555                         $order_string = " ORDER BY ";
1556                         foreach ($params['order'] AS $fields => $order) {
1557                                 if ($order === 'RAND()') {
1558                                         $order_string .= "RAND(), ";
1559                                 } elseif (!is_int($fields)) {
1560                                         $order_string .= "`" . $fields . "` " . ($order ? "DESC" : "ASC") . ", ";
1561                                 } else {
1562                                         $order_string .= "`" . $order . "`, ";
1563                                 }
1564                         }
1565                         $order_string = substr($order_string, 0, -2);
1566                 }
1567
1568                 $limit_string = '';
1569                 if (isset($params['limit']) && is_numeric($params['limit'])) {
1570                         $limit_string = " LIMIT " . intval($params['limit']);
1571                 }
1572
1573                 if (isset($params['limit']) && is_array($params['limit'])) {
1574                         $limit_string = " LIMIT " . intval($params['limit'][0]) . ", " . intval($params['limit'][1]);
1575                 }
1576
1577                 return $groupby_string . $order_string . $limit_string;
1578         }
1579
1580         /**
1581          * @brief Fills an array with data from a query
1582          *
1583          * @param object $stmt statement object
1584          * @param bool   $do_close
1585          * @return array Data array
1586          */
1587         public static function toArray($stmt, $do_close = true) {
1588                 if (is_bool($stmt)) {
1589                         return $stmt;
1590                 }
1591
1592                 $data = [];
1593                 while ($row = self::fetch($stmt)) {
1594                         $data[] = $row;
1595                 }
1596                 if ($do_close) {
1597                         self::close($stmt);
1598                 }
1599                 return $data;
1600         }
1601
1602         /**
1603          * @brief Returns the error number of the last query
1604          *
1605          * @return string Error number (0 if no error)
1606          */
1607         public static function errorNo() {
1608                 return self::$errorno;
1609         }
1610
1611         /**
1612          * @brief Returns the error message of the last query
1613          *
1614          * @return string Error message ('' if no error)
1615          */
1616         public static function errorMessage() {
1617                 return self::$error;
1618         }
1619
1620         /**
1621          * @brief Closes the current statement
1622          *
1623          * @param object $stmt statement object
1624          * @return boolean was the close successful?
1625          */
1626         public static function close($stmt) {
1627
1628                 $stamp1 = microtime(true);
1629
1630                 if (!is_object($stmt)) {
1631                         return false;
1632                 }
1633
1634                 switch (self::$driver) {
1635                         case 'pdo':
1636                                 $ret = $stmt->closeCursor();
1637                                 break;
1638                         case 'mysqli':
1639                                 // MySQLi offers both a mysqli_stmt and a mysqli_result class.
1640                                 // We should be careful not to assume the object type of $stmt
1641                                 // because DBA::p() has been able to return both types.
1642                                 if ($stmt instanceof mysqli_stmt) {
1643                                         $stmt->free_result();
1644                                         $ret = $stmt->close();
1645                                 } elseif ($stmt instanceof mysqli_result) {
1646                                         $stmt->free();
1647                                         $ret = true;
1648                                 } else {
1649                                         $ret = false;
1650                                 }
1651                                 break;
1652                 }
1653
1654                 self::$profiler->saveTimestamp($stamp1, 'database', System::callstack());
1655
1656                 return $ret;
1657         }
1658
1659         /**
1660          * @brief Return a list of database processes
1661          *
1662          * @return array
1663          *      'list' => List of processes, separated in their different states
1664          *      'amount' => Number of concurrent database processes
1665          * @throws \Exception
1666          */
1667         public static function processlist()
1668         {
1669                 $ret = self::p("SHOW PROCESSLIST");
1670                 $data = self::toArray($ret);
1671
1672                 $processes = 0;
1673                 $states = [];
1674                 foreach ($data as $process) {
1675                         $state = trim($process["State"]);
1676
1677                         // Filter out all non blocking processes
1678                         if (!in_array($state, ["", "init", "statistics", "updating"])) {
1679                                 ++$states[$state];
1680                                 ++$processes;
1681                         }
1682                 }
1683
1684                 $statelist = "";
1685                 foreach ($states as $state => $usage) {
1686                         if ($statelist != "") {
1687                                 $statelist .= ", ";
1688                         }
1689                         $statelist .= $state.": ".$usage;
1690                 }
1691                 return(["list" => $statelist, "amount" => $processes]);
1692         }
1693
1694         /**
1695          * Checks if $array is a filled array with at least one entry.
1696          *
1697          * @param mixed $array A filled array with at least one entry
1698          *
1699          * @return boolean Whether $array is a filled array or an object with rows
1700          */
1701         public static function isResult($array)
1702         {
1703                 // It could be a return value from an update statement
1704                 if (is_bool($array)) {
1705                         return $array;
1706                 }
1707
1708                 if (is_object($array)) {
1709                         return self::numRows($array) > 0;
1710                 }
1711
1712                 return (is_array($array) && (count($array) > 0));
1713         }
1714
1715         /**
1716          * @brief Callback function for "esc_array"
1717          *
1718          * @param mixed   $value         Array value
1719          * @param string  $key           Array key
1720          * @param boolean $add_quotation add quotation marks for string values
1721          * @return void
1722          */
1723         private static function escapeArrayCallback(&$value, $key, $add_quotation)
1724         {
1725                 if (!$add_quotation) {
1726                         if (is_bool($value)) {
1727                                 $value = ($value ? '1' : '0');
1728                         } else {
1729                                 $value = self::escape($value);
1730                         }
1731                         return;
1732                 }
1733
1734                 if (is_bool($value)) {
1735                         $value = ($value ? 'true' : 'false');
1736                 } elseif (is_float($value) || is_integer($value)) {
1737                         $value = (string) $value;
1738                 } else {
1739                         $value = "'" . self::escape($value) . "'";
1740                 }
1741         }
1742
1743         /**
1744          * @brief Escapes a whole array
1745          *
1746          * @param mixed   $arr           Array with values to be escaped
1747          * @param boolean $add_quotation add quotation marks for string values
1748          * @return void
1749          */
1750         public static function escapeArray(&$arr, $add_quotation = false)
1751         {
1752                 array_walk($arr, 'self::escapeArrayCallback', $add_quotation);
1753         }
1754 }