src/Database/DBA.php

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