2 // This file is part of Moodle - http://moodle.org/
4 // Moodle is free software: you can redistribute it and/or modify
5 // it under the terms of the GNU General Public License as published by
6 // the Free Software Foundation, either version 3 of the License, or
7 // (at your option) any later version.
9 // Moodle is distributed in the hope that it will be useful,
10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 // GNU General Public License for more details.
14 // You should have received a copy of the GNU General Public License
15 // along with Moodle. If not, see <http://www.gnu.org/licenses/>.
18 * Native mysqli class representing moodle database interface.
21 * @copyright 2008 Petr Skoda (http://skodak.org)
22 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
25 defined('MOODLE_INTERNAL') ||
die();
27 require_once(__DIR__
.'/moodle_database.php');
28 require_once(__DIR__
.'/mysqli_native_moodle_recordset.php');
29 require_once(__DIR__
.'/mysqli_native_moodle_temptables.php');
32 * Native mysqli class representing moodle database interface.
35 * @copyright 2008 Petr Skoda (http://skodak.org)
36 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
38 class mysqli_native_moodle_database
extends moodle_database
{
40 /** @var mysqli $mysqli */
41 protected $mysqli = null;
42 /** @var bool is compressed row format supported cache */
43 protected $compressedrowformatsupported = null;
45 private $transactions_supported = null;
48 * Attempt to create the database
49 * @param string $dbhost
50 * @param string $dbuser
51 * @param string $dbpass
52 * @param string $dbname
53 * @return bool success
54 * @throws dml_exception A DML specific exception is thrown for any errors.
56 public function create_database($dbhost, $dbuser, $dbpass, $dbname, array $dboptions=null) {
57 $driverstatus = $this->driver_installed();
59 if ($driverstatus !== true) {
60 throw new dml_exception('dbdriverproblem', $driverstatus);
63 if (!empty($dboptions['dbsocket'])
64 and (strpos($dboptions['dbsocket'], '/') !== false or strpos($dboptions['dbsocket'], '\\') !== false)) {
65 $dbsocket = $dboptions['dbsocket'];
67 $dbsocket = ini_get('mysqli.default_socket');
69 if (empty($dboptions['dbport'])) {
70 $dbport = (int)ini_get('mysqli.default_port');
72 $dbport = (int)$dboptions['dbport'];
74 // verify ini.get does not return nonsense
79 $conn = new mysqli($dbhost, $dbuser, $dbpass, '', $dbport, $dbsocket); // Connect without db
80 $dberr = ob_get_contents();
82 $errorno = @$conn->connect_errno
;
85 throw new dml_connection_exception($dberr);
88 // Normally a check would be done before setting utf8mb4, but the database can be created
89 // before the enviroment checks are done. We'll proceed with creating the database and then do checks next.
91 if (isset($dboptions['dbcollation']) and (strpos($dboptions['dbcollation'], 'utf8_') === 0
92 ||
strpos($dboptions['dbcollation'], 'utf8mb4_') === 0)) {
93 $collation = $dboptions['dbcollation'];
94 $collationinfo = explode('_', $dboptions['dbcollation']);
95 $charset = reset($collationinfo);
97 $collation = 'utf8mb4_unicode_ci';
100 $result = $conn->query("CREATE DATABASE $dbname DEFAULT CHARACTER SET $charset DEFAULT COLLATE ".$collation);
105 throw new dml_exception('cannotcreatedb');
112 * Detects if all needed PHP stuff installed.
113 * Note: can be used before connect()
114 * @return mixed true if ok, string if something
116 public function driver_installed() {
117 if (!extension_loaded('mysqli')) {
118 return get_string('mysqliextensionisnotpresentinphp', 'install');
124 * Returns database family type - describes SQL dialect
125 * Note: can be used before connect()
126 * @return string db family name (mysql, postgres, mssql, oracle, etc.)
128 public function get_dbfamily() {
133 * Returns more specific database driver type
134 * Note: can be used before connect()
135 * @return string db type mysqli, pgsql, oci, mssql, sqlsrv
137 protected function get_dbtype() {
142 * Returns general database library name
143 * Note: can be used before connect()
144 * @return string db type pdo, native
146 protected function get_dblibrary() {
151 * Returns the current MySQL db engine.
153 * This is an ugly workaround for MySQL default engine problems,
154 * Moodle is designed to work best on ACID compliant databases
155 * with full transaction support. Do not use MyISAM.
157 * @return string or null MySQL engine name
159 public function get_dbengine() {
160 if (isset($this->dboptions
['dbengine'])) {
161 return $this->dboptions
['dbengine'];
164 if ($this->external
) {
170 // Look for current engine of our config table (the first table that gets created),
171 // so that we create all tables with the same engine.
172 $sql = "SELECT engine
173 FROM INFORMATION_SCHEMA.TABLES
174 WHERE table_schema = DATABASE() AND table_name = '{$this->prefix}config'";
175 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
176 $result = $this->mysqli
->query($sql);
177 $this->query_end($result);
178 if ($rec = $result->fetch_assoc()) {
179 // MySQL 8 BC: information_schema.* returns the fields in upper case.
180 $rec = array_change_key_case($rec, CASE_LOWER
);
181 $engine = $rec['engine'];
186 // Cache the result to improve performance.
187 $this->dboptions
['dbengine'] = $engine;
191 // Get the default database engine.
192 $sql = "SELECT @@default_storage_engine engine";
193 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
194 $result = $this->mysqli
->query($sql);
195 $this->query_end($result);
196 if ($rec = $result->fetch_assoc()) {
197 $engine = $rec['engine'];
201 if ($engine === 'MyISAM') {
202 // we really do not want MyISAM for Moodle, InnoDB or XtraDB is a reasonable defaults if supported
203 $sql = "SHOW STORAGE ENGINES";
204 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
205 $result = $this->mysqli
->query($sql);
206 $this->query_end($result);
208 while ($res = $result->fetch_assoc()) {
209 if ($res['Support'] === 'YES' or $res['Support'] === 'DEFAULT') {
210 $engines[$res['Engine']] = true;
214 if (isset($engines['InnoDB'])) {
217 if (isset($engines['XtraDB'])) {
222 // Cache the result to improve performance.
223 $this->dboptions
['dbengine'] = $engine;
228 * Returns the current MySQL db collation.
230 * This is an ugly workaround for MySQL default collation problems.
232 * @return string or null MySQL collation name
234 public function get_dbcollation() {
235 if (isset($this->dboptions
['dbcollation'])) {
236 return $this->dboptions
['dbcollation'];
238 if ($this->external
) {
244 // Look for current collation of our config table (the first table that gets created),
245 // so that we create all tables with the same collation.
246 $sql = "SELECT collation_name
247 FROM INFORMATION_SCHEMA.COLUMNS
248 WHERE table_schema = DATABASE() AND table_name = '{$this->prefix}config' AND column_name = 'value'";
249 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
250 $result = $this->mysqli
->query($sql);
251 $this->query_end($result);
252 if ($rec = $result->fetch_assoc()) {
253 // MySQL 8 BC: information_schema.* returns the fields in upper case.
254 $rec = array_change_key_case($rec, CASE_LOWER
);
255 $collation = $rec['collation_name'];
261 // Get the default database collation, but only if using UTF-8.
262 $sql = "SELECT @@collation_database";
263 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
264 $result = $this->mysqli
->query($sql);
265 $this->query_end($result);
266 if ($rec = $result->fetch_assoc()) {
267 if (strpos($rec['@@collation_database'], 'utf8_') === 0 ||
strpos($rec['@@collation_database'], 'utf8mb4_') === 0) {
268 $collation = $rec['@@collation_database'];
275 // We want only utf8 compatible collations.
277 $sql = "SHOW COLLATION WHERE Collation LIKE 'utf8mb4\_%' AND Charset = 'utf8mb4'";
278 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
279 $result = $this->mysqli
->query($sql);
280 $this->query_end($result);
281 while ($res = $result->fetch_assoc()) {
282 $collation = $res['Collation'];
283 if (strtoupper($res['Default']) === 'YES') {
284 $collation = $res['Collation'];
291 // Cache the result to improve performance.
292 $this->dboptions
['dbcollation'] = $collation;
297 * Tests if the Antelope file format is still supported or it has been removed.
298 * When removed, only Barracuda file format is supported, given the XtraDB/InnoDB engine.
300 * @return bool True if the Antelope file format has been removed; otherwise, false.
302 protected function is_antelope_file_format_no_more_supported() {
303 // Breaking change: Antelope file format support has been removed from both MySQL and MariaDB.
304 // The following InnoDB file format configuration parameters were deprecated and then removed:
305 // - innodb_file_format
306 // - innodb_file_format_check
307 // - innodb_file_format_max
308 // - innodb_large_prefix
309 // 1. MySQL: deprecated in 5.7.7 and removed 8.0.0+.
310 $ismysqlge8d0d0 = ($this->get_dbtype() == 'mysqli') &&
311 version_compare($this->get_server_info()['version'], '8.0.0', '>=');
312 // 2. MariaDB: deprecated in 10.2.0 and removed 10.3.1+.
313 $ismariadbge10d3d1 = ($this->get_dbtype() == 'mariadb') &&
314 version_compare($this->get_server_info()['version'], '10.3.1', '>=');
316 return $ismysqlge8d0d0 ||
$ismariadbge10d3d1;
320 * Get the row format from the database schema.
322 * @param string $table
323 * @return string row_format name or null if not known or table does not exist.
325 public function get_row_format($table = null) {
328 $table = $this->mysqli
->real_escape_string($table);
329 $sql = "SELECT row_format
330 FROM INFORMATION_SCHEMA.TABLES
331 WHERE table_schema = DATABASE() AND table_name = '{$this->prefix}$table'";
333 if ($this->is_antelope_file_format_no_more_supported()) {
334 // Breaking change: Antelope file format support has been removed, only Barracuda.
335 $dbengine = $this->get_dbengine();
336 $supporteddbengines = array('InnoDB', 'XtraDB');
337 if (in_array($dbengine, $supporteddbengines)) {
338 $rowformat = 'Barracuda';
344 $sql = "SHOW VARIABLES LIKE 'innodb_file_format'";
346 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
347 $result = $this->mysqli
->query($sql);
348 $this->query_end($result);
349 if ($rec = $result->fetch_assoc()) {
350 // MySQL 8 BC: information_schema.* returns the fields in upper case.
351 $rec = array_change_key_case($rec, CASE_LOWER
);
353 $rowformat = $rec['row_format'];
355 $rowformat = $rec['value'];
364 * Is this database compatible with compressed row format?
365 * This feature is necessary for support of large number of text
366 * columns in InnoDB/XtraDB database.
368 * @param bool $cached use cached result
369 * @return bool true if table can be created or changed to compressed row format.
371 public function is_compressed_row_format_supported($cached = true) {
372 if ($cached and isset($this->compressedrowformatsupported
)) {
373 return($this->compressedrowformatsupported
);
376 $engine = strtolower($this->get_dbengine());
377 $info = $this->get_server_info();
379 if (version_compare($info['version'], '5.5.0') < 0) {
380 // MySQL 5.1 is not supported here because we cannot read the file format.
381 $this->compressedrowformatsupported
= false;
383 } else if ($engine !== 'innodb' and $engine !== 'xtradb') {
384 // Other engines are not supported, most probably not compatible.
385 $this->compressedrowformatsupported
= false;
387 } else if (!$this->is_file_per_table_enabled()) {
388 $this->compressedrowformatsupported
= false;
390 } else if ($this->get_row_format() !== 'Barracuda') {
391 $this->compressedrowformatsupported
= false;
394 // All the tests passed, we can safely use ROW_FORMAT=Compressed in sql statements.
395 $this->compressedrowformatsupported
= true;
398 return $this->compressedrowformatsupported
;
402 * Check the database to see if innodb_file_per_table is on.
404 * @return bool True if on otherwise false.
406 public function is_file_per_table_enabled() {
407 if ($filepertable = $this->get_record_sql("SHOW VARIABLES LIKE 'innodb_file_per_table'")) {
408 if ($filepertable->value
== 'ON') {
416 * Check the database to see if innodb_large_prefix is on.
418 * @return bool True if on otherwise false.
420 public function is_large_prefix_enabled() {
421 if ($this->is_antelope_file_format_no_more_supported()) {
422 // Breaking change: Antelope file format support has been removed, only Barracuda.
426 if ($largeprefix = $this->get_record_sql("SHOW VARIABLES LIKE 'innodb_large_prefix'")) {
427 if ($largeprefix->value
== 'ON') {
435 * Determine if the row format should be set to compressed, dynamic, or default.
437 * Terrible kludge. If we're using utf8mb4 AND we're using InnoDB, we need to specify row format to
438 * be either dynamic or compressed (default is compact) in order to allow for bigger indexes (MySQL
439 * errors #1709 and #1071).
441 * @param string $engine The database engine being used. Will be looked up if not supplied.
442 * @param string $collation The database collation to use. Will look up the current collation if not supplied.
443 * @return string An sql fragment to add to sql statements.
445 public function get_row_format_sql($engine = null, $collation = null) {
447 if (!isset($engine)) {
448 $engine = $this->get_dbengine();
450 $engine = strtolower($engine);
452 if (!isset($collation)) {
453 $collation = $this->get_dbcollation();
457 if (($engine === 'innodb' ||
$engine === 'xtradb') && strpos($collation, 'utf8mb4_') === 0) {
458 if ($this->is_compressed_row_format_supported()) {
459 $rowformat = "ROW_FORMAT=Compressed";
461 $rowformat = "ROW_FORMAT=Dynamic";
468 * Returns localised database type name
469 * Note: can be used before connect()
472 public function get_name() {
473 return get_string('nativemysqli', 'install');
477 * Returns localised database configuration help.
478 * Note: can be used before connect()
481 public function get_configuration_help() {
482 return get_string('nativemysqlihelp', 'install');
486 * Diagnose database and tables, this function is used
487 * to verify database and driver settings, db engine types, etc.
489 * @return string null means everything ok, string means problem found.
491 public function diagnose() {
492 $sloppymyisamfound = false;
493 $prefix = str_replace('_', '\\_', $this->prefix
);
494 $sql = "SELECT COUNT('x')
495 FROM INFORMATION_SCHEMA.TABLES
496 WHERE table_schema = DATABASE()
497 AND table_name LIKE BINARY '$prefix%'
498 AND Engine = 'MyISAM'";
499 $this->query_start($sql, null, SQL_QUERY_AUX
);
500 $result = $this->mysqli
->query($sql);
501 $this->query_end($result);
503 if ($arr = $result->fetch_assoc()) {
504 $count = reset($arr);
506 $sloppymyisamfound = true;
512 if ($sloppymyisamfound) {
513 return get_string('myisamproblem', 'error');
521 * Must be called before other methods.
522 * @param string $dbhost The database host.
523 * @param string $dbuser The database username.
524 * @param string $dbpass The database username's password.
525 * @param string $dbname The name of the database being connected to.e
526 * @param mixed $prefix string means moodle db prefix, false used for external databases where prefix not used
527 * @param array $dboptions driver specific options
528 * @return bool success
530 public function connect($dbhost, $dbuser, $dbpass, $dbname, $prefix, array $dboptions=null) {
531 $driverstatus = $this->driver_installed();
533 if ($driverstatus !== true) {
534 throw new dml_exception('dbdriverproblem', $driverstatus);
537 $this->store_settings($dbhost, $dbuser, $dbpass, $dbname, $prefix, $dboptions);
539 // dbsocket is used ONLY if host is NULL or 'localhost',
540 // you can not disable it because it is always tried if dbhost is 'localhost'
541 if (!empty($this->dboptions
['dbsocket'])
542 and (strpos($this->dboptions
['dbsocket'], '/') !== false or strpos($this->dboptions
['dbsocket'], '\\') !== false)) {
543 $dbsocket = $this->dboptions
['dbsocket'];
545 $dbsocket = ini_get('mysqli.default_socket');
547 if (empty($this->dboptions
['dbport'])) {
548 $dbport = (int)ini_get('mysqli.default_port');
550 $dbport = (int)$this->dboptions
['dbport'];
552 // verify ini.get does not return nonsense
553 if (empty($dbport)) {
556 if ($dbhost and !empty($this->dboptions
['dbpersist'])) {
557 $dbhost = "p:$dbhost";
559 $this->mysqli
= @new
mysqli($dbhost, $dbuser, $dbpass, $dbname, $dbport, $dbsocket);
561 if ($this->mysqli
->connect_errno
!== 0) {
562 $dberr = $this->mysqli
->connect_error
;
563 $this->mysqli
= null;
564 throw new dml_connection_exception($dberr);
567 // Disable logging until we are fully setup.
568 $this->query_log_prevent();
570 if (isset($dboptions['dbcollation'])) {
571 $collationinfo = explode('_', $dboptions['dbcollation']);
572 $this->dboptions
['dbcollation'] = $dboptions['dbcollation'];
574 $collationinfo = explode('_', $this->get_dbcollation());
576 $charset = reset($collationinfo);
578 $this->query_start("--set_charset()", null, SQL_QUERY_AUX
);
579 $this->mysqli
->set_charset($charset);
580 $this->query_end(true);
582 // If available, enforce strict mode for the session. That guaranties
583 // standard behaviour under some situations, avoiding some MySQL nasty
584 // habits like truncating data or performing some transparent cast losses.
585 // With strict mode enforced, Moodle DB layer will be consistently throwing
586 // the corresponding exceptions as expected.
587 $si = $this->get_server_info();
588 if (version_compare($si['version'], '5.0.2', '>=')) {
589 $sql = "SET SESSION sql_mode = 'STRICT_ALL_TABLES'";
590 $this->query_start($sql, null, SQL_QUERY_AUX
);
591 $result = $this->mysqli
->query($sql);
592 $this->query_end($result);
595 // We can enable logging now.
596 $this->query_log_allow();
598 // Connection stabilised and configured, going to instantiate the temptables controller
599 $this->temptables
= new mysqli_native_moodle_temptables($this);
605 * Close database connection and release all resources
606 * and memory (especially circular memory references).
607 * Do NOT use connect() again, create a new instance if needed.
609 public function dispose() {
610 parent
::dispose(); // Call parent dispose to write/close session and other common stuff before closing connection
612 $this->mysqli
->close();
613 $this->mysqli
= null;
618 * Returns database server info array
619 * @return array Array containing 'description' and 'version' info
621 public function get_server_info() {
622 return array('description'=>$this->mysqli
->server_info
, 'version'=>$this->mysqli
->server_info
);
626 * Returns supported query parameter types
627 * @return int bitmask of accepted SQL_PARAMS_*
629 protected function allowed_param_types() {
630 return SQL_PARAMS_QM
;
634 * Returns last error reported by database engine.
635 * @return string error message
637 public function get_last_error() {
638 return $this->mysqli
->error
;
642 * Return tables in database WITHOUT current prefix
643 * @param bool $usecache if true, returns list of cached tables.
644 * @return array of table names in lowercase and without prefix
646 public function get_tables($usecache=true) {
647 if ($usecache and $this->tables
!== null) {
648 return $this->tables
;
650 $this->tables
= array();
651 $prefix = str_replace('_', '\\_', $this->prefix
);
652 $sql = "SHOW TABLES LIKE '$prefix%'";
653 $this->query_start($sql, null, SQL_QUERY_AUX
);
654 $result = $this->mysqli
->query($sql);
655 $this->query_end($result);
656 $len = strlen($this->prefix
);
658 while ($arr = $result->fetch_assoc()) {
659 $tablename = reset($arr);
660 $tablename = substr($tablename, $len);
661 $this->tables
[$tablename] = $tablename;
666 // Add the currently available temptables
667 $this->tables
= array_merge($this->tables
, $this->temptables
->get_temptables());
668 return $this->tables
;
672 * Return table indexes - everything lowercased.
673 * @param string $table The table we want to get indexes from.
674 * @return array An associative array of indexes containing 'unique' flag and 'columns' being indexed
676 public function get_indexes($table) {
678 $sql = "SHOW INDEXES FROM {$this->prefix}$table";
679 $this->query_start($sql, null, SQL_QUERY_AUX
);
680 $result = $this->mysqli
->query($sql);
682 $this->query_end($result);
683 } catch (dml_read_exception
$e) {
684 return $indexes; // table does not exist - no indexes...
687 while ($res = $result->fetch_object()) {
688 if ($res->Key_name
=== 'PRIMARY') {
691 if (!isset($indexes[$res->Key_name
])) {
692 $indexes[$res->Key_name
] = array('unique'=>empty($res->Non_unique
), 'columns'=>array());
694 $indexes[$res->Key_name
]['columns'][$res->Seq_in_index
-1] = $res->Column_name
;
702 * Returns detailed information about columns in table. This information is cached internally.
703 * @param string $table name
704 * @param bool $usecache
705 * @return database_column_info[] array of database_column_info objects indexed with column names
707 public function get_columns($table, $usecache=true) {
709 if ($this->temptables
->is_temptable($table)) {
710 if ($data = $this->get_temp_tables_cache()->get($table)) {
714 if ($data = $this->get_metacache()->get($table)) {
720 $structure = array();
722 $sql = "SELECT column_name, data_type, character_maximum_length, numeric_precision,
723 numeric_scale, is_nullable, column_type, column_default, column_key, extra
724 FROM information_schema.columns
725 WHERE table_name = '" . $this->prefix
.$table . "'
726 AND table_schema = '" . $this->dbname
. "'
727 ORDER BY ordinal_position";
728 $this->query_start($sql, null, SQL_QUERY_AUX
);
729 $result = $this->mysqli
->query($sql);
730 $this->query_end(true); // Don't want to throw anything here ever. MDL-30147
732 if ($result === false) {
736 if ($result->num_rows
> 0) {
737 // standard table exists
738 while ($rawcolumn = $result->fetch_assoc()) {
739 // MySQL 8 BC: information_schema.* returns the fields in upper case.
740 $rawcolumn = array_change_key_case($rawcolumn, CASE_LOWER
);
741 $info = (object)$this->get_column_info((object)$rawcolumn);
742 $structure[$info->name
] = new database_column_info($info);
747 // temporary tables are not in information schema, let's try it the old way
749 $sql = "SHOW COLUMNS FROM {$this->prefix}$table";
750 $this->query_start($sql, null, SQL_QUERY_AUX
);
751 $result = $this->mysqli
->query($sql);
752 $this->query_end(true);
753 if ($result === false) {
756 while ($rawcolumn = $result->fetch_assoc()) {
757 $rawcolumn = (object)array_change_key_case($rawcolumn, CASE_LOWER
);
758 $rawcolumn->column_name
= $rawcolumn->field
; unset($rawcolumn->field
);
759 $rawcolumn->column_type
= $rawcolumn->type
; unset($rawcolumn->type
);
760 $rawcolumn->character_maximum_length
= null;
761 $rawcolumn->numeric_precision
= null;
762 $rawcolumn->numeric_scale
= null;
763 $rawcolumn->is_nullable
= $rawcolumn->null; unset($rawcolumn->null);
764 $rawcolumn->column_default
= $rawcolumn->default; unset($rawcolumn->default);
765 $rawcolumn->column_key
= $rawcolumn->key
; unset($rawcolumn->key
);
767 if (preg_match('/(enum|varchar)\((\d+)\)/i', $rawcolumn->column_type
, $matches)) {
768 $rawcolumn->data_type
= $matches[1];
769 $rawcolumn->character_maximum_length
= $matches[2];
771 } else if (preg_match('/([a-z]*int[a-z]*)\((\d+)\)/i', $rawcolumn->column_type
, $matches)) {
772 $rawcolumn->data_type
= $matches[1];
773 $rawcolumn->numeric_precision
= $matches[2];
774 $rawcolumn->max_length
= $rawcolumn->numeric_precision
;
776 $type = strtoupper($matches[1]);
777 if ($type === 'BIGINT') {
779 } else if ($type === 'INT' or $type === 'INTEGER') {
781 } else if ($type === 'MEDIUMINT') {
783 } else if ($type === 'SMALLINT') {
785 } else if ($type === 'TINYINT') {
788 // This should not happen.
791 if ($maxlength < $rawcolumn->max_length
) {
792 $rawcolumn->max_length
= $maxlength;
795 } else if (preg_match('/(decimal)\((\d+),(\d+)\)/i', $rawcolumn->column_type
, $matches)) {
796 $rawcolumn->data_type
= $matches[1];
797 $rawcolumn->numeric_precision
= $matches[2];
798 $rawcolumn->numeric_scale
= $matches[3];
800 } else if (preg_match('/(double|float)(\((\d+),(\d+)\))?/i', $rawcolumn->column_type
, $matches)) {
801 $rawcolumn->data_type
= $matches[1];
802 $rawcolumn->numeric_precision
= isset($matches[3]) ?
$matches[3] : null;
803 $rawcolumn->numeric_scale
= isset($matches[4]) ?
$matches[4] : null;
805 } else if (preg_match('/([a-z]*text)/i', $rawcolumn->column_type
, $matches)) {
806 $rawcolumn->data_type
= $matches[1];
807 $rawcolumn->character_maximum_length
= -1; // unknown
809 } else if (preg_match('/([a-z]*blob)/i', $rawcolumn->column_type
, $matches)) {
810 $rawcolumn->data_type
= $matches[1];
813 $rawcolumn->data_type
= $rawcolumn->column_type
;
816 $info = $this->get_column_info($rawcolumn);
817 $structure[$info->name
] = new database_column_info($info);
823 if ($this->temptables
->is_temptable($table)) {
824 $this->get_temp_tables_cache()->set($table, $structure);
826 $this->get_metacache()->set($table, $structure);
834 * Indicates whether column information retrieved from `information_schema.columns` has default values quoted or not.
835 * @return boolean True when default values are quoted (breaking change); otherwise, false.
837 protected function has_breaking_change_quoted_defaults() {
842 * Indicates whether SQL_MODE default value has changed in a not backward compatible way.
843 * @return boolean True when SQL_MODE breaks BC; otherwise, false.
845 public function has_breaking_change_sqlmode() {
850 * Returns moodle column info for raw column from information schema.
851 * @param stdClass $rawcolumn
852 * @return stdClass standardised colum info
854 private function get_column_info(stdClass
$rawcolumn) {
855 $rawcolumn = (object)$rawcolumn;
856 $info = new stdClass();
857 $info->name
= $rawcolumn->column_name
;
858 $info->type
= $rawcolumn->data_type
;
859 $info->meta_type
= $this->mysqltype2moodletype($rawcolumn->data_type
);
860 if ($this->has_breaking_change_quoted_defaults()) {
861 $info->default_value
= trim($rawcolumn->column_default
, "'");
862 if ($info->default_value
=== 'NULL') {
863 $info->default_value
= null;
866 $info->default_value
= $rawcolumn->column_default
;
868 $info->has_default
= !is_null($info->default_value
);
869 $info->not_null
= ($rawcolumn->is_nullable
=== 'NO');
870 $info->primary_key
= ($rawcolumn->column_key
=== 'PRI');
871 $info->binary
= false;
872 $info->unsigned
= null;
873 $info->auto_increment
= false;
874 $info->unique
= null;
877 if ($info->meta_type
=== 'C') {
878 $info->max_length
= $rawcolumn->character_maximum_length
;
880 } else if ($info->meta_type
=== 'I') {
881 if ($info->primary_key
) {
882 $info->meta_type
= 'R';
883 $info->unique
= true;
885 // Return number of decimals, not bytes here.
886 $info->max_length
= $rawcolumn->numeric_precision
;
887 if (preg_match('/([a-z]*int[a-z]*)\((\d+)\)/i', $rawcolumn->column_type
, $matches)) {
888 $type = strtoupper($matches[1]);
889 if ($type === 'BIGINT') {
891 } else if ($type === 'INT' or $type === 'INTEGER') {
893 } else if ($type === 'MEDIUMINT') {
895 } else if ($type === 'SMALLINT') {
897 } else if ($type === 'TINYINT') {
900 // This should not happen.
903 // It is possible that display precision is different from storage type length,
904 // always use the smaller value to make sure our data fits.
905 if ($maxlength < $info->max_length
) {
906 $info->max_length
= $maxlength;
909 $info->unsigned
= (stripos($rawcolumn->column_type
, 'unsigned') !== false);
910 $info->auto_increment
= (strpos($rawcolumn->extra
, 'auto_increment') !== false);
912 } else if ($info->meta_type
=== 'N') {
913 $info->max_length
= $rawcolumn->numeric_precision
;
914 $info->scale
= $rawcolumn->numeric_scale
;
915 $info->unsigned
= (stripos($rawcolumn->column_type
, 'unsigned') !== false);
917 } else if ($info->meta_type
=== 'X') {
918 if ("$rawcolumn->character_maximum_length" === '4294967295') { // watch out for PHP max int limits!
919 // means maximum moodle size for text column, in other drivers it may also mean unknown size
920 $info->max_length
= -1;
922 $info->max_length
= $rawcolumn->character_maximum_length
;
924 $info->primary_key
= false;
926 } else if ($info->meta_type
=== 'B') {
927 $info->max_length
= -1;
928 $info->primary_key
= false;
929 $info->binary
= true;
936 * Normalise column type.
937 * @param string $mysql_type
938 * @return string one character
939 * @throws dml_exception
941 private function mysqltype2moodletype($mysql_type) {
944 switch(strtoupper($mysql_type)) {
997 throw new dml_exception('invalidmysqlnativetype', $mysql_type);
1003 * Normalise values based in RDBMS dependencies (booleans, LOBs...)
1005 * @param database_column_info $column column metadata corresponding with the value we are going to normalise
1006 * @param mixed $value value we are going to normalise
1007 * @return mixed the normalised value
1009 protected function normalise_value($column, $value) {
1010 $this->detect_objects($value);
1012 if (is_bool($value)) { // Always, convert boolean to int
1013 $value = (int)$value;
1015 } else if ($value === '') {
1016 if ($column->meta_type
== 'I' or $column->meta_type
== 'F' or $column->meta_type
== 'N') {
1017 $value = 0; // prevent '' problems in numeric fields
1019 // Any float value being stored in varchar or text field is converted to string to avoid
1020 // any implicit conversion by MySQL
1021 } else if (is_float($value) and ($column->meta_type
== 'C' or $column->meta_type
== 'X')) {
1028 * Is this database compatible with utf8?
1031 public function setup_is_unicodedb() {
1032 // All new tables are created with this collation, we just have to make sure it is utf8 compatible,
1033 // if config table already exists it has this collation too.
1034 $collation = $this->get_dbcollation();
1036 $collationinfo = explode('_', $collation);
1037 $charset = reset($collationinfo);
1039 $sql = "SHOW COLLATION WHERE Collation ='$collation' AND Charset = '$charset'";
1040 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
1041 $result = $this->mysqli
->query($sql);
1042 $this->query_end($result);
1043 if ($result->fetch_assoc()) {
1054 * Do NOT use in code, to be used by database_manager only!
1055 * @param string|array $sql query
1056 * @param array|null $tablenames an array of xmldb table names affected by this request.
1058 * @throws ddl_change_structure_exception A DDL specific exception is thrown for any errors.
1060 public function change_database_structure($sql, $tablenames = null) {
1061 $this->get_manager(); // Includes DDL exceptions classes ;-)
1062 if (is_array($sql)) {
1063 $sql = implode("\n;\n", $sql);
1067 $this->query_start($sql, null, SQL_QUERY_STRUCTURE
);
1068 $result = $this->mysqli
->multi_query($sql);
1069 if ($result === false) {
1070 $this->query_end(false);
1072 while ($this->mysqli
->more_results()) {
1073 $result = $this->mysqli
->next_result();
1074 if ($result === false) {
1075 $this->query_end(false);
1078 $this->query_end(true);
1079 } catch (ddl_change_structure_exception
$e) {
1080 while (@$this->mysqli
->more_results()) {
1081 @$this->mysqli
->next_result();
1083 $this->reset_caches($tablenames);
1087 $this->reset_caches($tablenames);
1092 * Very ugly hack which emulates bound parameters in queries
1093 * because prepared statements do not use query cache.
1095 protected function emulate_bound_params($sql, array $params=null) {
1096 if (empty($params)) {
1099 // ok, we have verified sql statement with ? and correct number of params
1100 $parts = array_reverse(explode('?', $sql));
1101 $return = array_pop($parts);
1102 foreach ($params as $param) {
1103 if (is_bool($param)) {
1104 $return .= (int)$param;
1105 } else if (is_null($param)) {
1107 } else if (is_number($param)) {
1108 $return .= "'".$param."'"; // we have to always use strings because mysql is using weird automatic int casting
1109 } else if (is_float($param)) {
1112 $param = $this->mysqli
->real_escape_string($param);
1113 $return .= "'$param'";
1115 $return .= array_pop($parts);
1121 * Execute general sql query. Should be used only when no other method suitable.
1122 * Do NOT use this to make changes in db structure, use database_manager methods instead!
1123 * @param string $sql query
1124 * @param array $params query parameters
1126 * @throws dml_exception A DML specific exception is thrown for any errors.
1128 public function execute($sql, array $params=null) {
1129 list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
1131 if (strpos($sql, ';') !== false) {
1132 throw new coding_exception('moodle_database::execute() Multiple sql statements found or bound parameters not used properly in query!');
1135 $rawsql = $this->emulate_bound_params($sql, $params);
1137 $this->query_start($sql, $params, SQL_QUERY_UPDATE
);
1138 $result = $this->mysqli
->query($rawsql);
1139 $this->query_end($result);
1141 if ($result === true) {
1151 * Get a number of records as a moodle_recordset using a SQL statement.
1153 * Since this method is a little less readable, use of it should be restricted to
1154 * code where it's possible there might be large datasets being returned. For known
1155 * small datasets use get_records_sql - it leads to simpler code.
1157 * The return type is like:
1158 * @see function get_recordset.
1160 * @param string $sql the SQL select query to execute.
1161 * @param array $params array of sql parameters
1162 * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
1163 * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
1164 * @return moodle_recordset instance
1165 * @throws dml_exception A DML specific exception is thrown for any errors.
1167 public function get_recordset_sql($sql, array $params=null, $limitfrom=0, $limitnum=0) {
1169 list($limitfrom, $limitnum) = $this->normalise_limit_from_num($limitfrom, $limitnum);
1171 if ($limitfrom or $limitnum) {
1172 if ($limitnum < 1) {
1173 $limitnum = "18446744073709551615";
1175 $sql .= " LIMIT $limitfrom, $limitnum";
1178 list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
1179 $rawsql = $this->emulate_bound_params($sql, $params);
1181 $this->query_start($sql, $params, SQL_QUERY_SELECT
);
1182 // no MYSQLI_USE_RESULT here, it would block write ops on affected tables
1183 $result = $this->mysqli
->query($rawsql, MYSQLI_STORE_RESULT
);
1184 $this->query_end($result);
1186 return $this->create_recordset($result);
1190 * Get all records from a table.
1192 * This method works around potential memory problems and may improve performance,
1193 * this method may block access to table until the recordset is closed.
1195 * @param string $table Name of database table.
1196 * @return moodle_recordset A moodle_recordset instance {@link function get_recordset}.
1197 * @throws dml_exception A DML specific exception is thrown for any errors.
1199 public function export_table_recordset($table) {
1200 $sql = $this->fix_table_names("SELECT * FROM {{$table}}");
1202 $this->query_start($sql, array(), SQL_QUERY_SELECT
);
1203 // MYSQLI_STORE_RESULT may eat all memory for large tables, unfortunately MYSQLI_USE_RESULT blocks other queries.
1204 $result = $this->mysqli
->query($sql, MYSQLI_USE_RESULT
);
1205 $this->query_end($result);
1207 return $this->create_recordset($result);
1210 protected function create_recordset($result) {
1211 return new mysqli_native_moodle_recordset($result);
1215 * Get a number of records as an array of objects using a SQL statement.
1217 * Return value is like:
1218 * @see function get_records.
1220 * @param string $sql the SQL select query to execute. The first column of this SELECT statement
1221 * must be a unique value (usually the 'id' field), as it will be used as the key of the
1223 * @param array $params array of sql parameters
1224 * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
1225 * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
1226 * @return array of objects, or empty array if no records were found
1227 * @throws dml_exception A DML specific exception is thrown for any errors.
1229 public function get_records_sql($sql, array $params=null, $limitfrom=0, $limitnum=0) {
1231 list($limitfrom, $limitnum) = $this->normalise_limit_from_num($limitfrom, $limitnum);
1233 if ($limitfrom or $limitnum) {
1234 if ($limitnum < 1) {
1235 $limitnum = "18446744073709551615";
1237 $sql .= " LIMIT $limitfrom, $limitnum";
1240 list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
1241 $rawsql = $this->emulate_bound_params($sql, $params);
1243 $this->query_start($sql, $params, SQL_QUERY_SELECT
);
1244 $result = $this->mysqli
->query($rawsql, MYSQLI_STORE_RESULT
);
1245 $this->query_end($result);
1249 while($row = $result->fetch_assoc()) {
1250 $row = array_change_key_case($row, CASE_LOWER
);
1252 if (isset($return[$id])) {
1253 $colname = key($row);
1254 debugging("Did you remember to make the first column something unique in your call to get_records? Duplicate value '$id' found in column '$colname'.", DEBUG_DEVELOPER
);
1256 $return[$id] = (object)$row;
1264 * Selects records and return values (first field) as an array using a SQL statement.
1266 * @param string $sql The SQL query
1267 * @param array $params array of sql parameters
1268 * @return array of values
1269 * @throws dml_exception A DML specific exception is thrown for any errors.
1271 public function get_fieldset_sql($sql, array $params=null) {
1272 list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
1273 $rawsql = $this->emulate_bound_params($sql, $params);
1275 $this->query_start($sql, $params, SQL_QUERY_SELECT
);
1276 $result = $this->mysqli
->query($rawsql, MYSQLI_STORE_RESULT
);
1277 $this->query_end($result);
1281 while($row = $result->fetch_assoc()) {
1282 $return[] = reset($row);
1290 * Insert new record into database, as fast as possible, no safety checks, lobs not supported.
1291 * @param string $table name
1292 * @param mixed $params data record as object or array
1293 * @param bool $returnit return it of inserted record
1294 * @param bool $bulk true means repeated inserts expected
1295 * @param bool $customsequence true if 'id' included in $params, disables $returnid
1296 * @return bool|int true or new id
1297 * @throws dml_exception A DML specific exception is thrown for any errors.
1299 public function insert_record_raw($table, $params, $returnid=true, $bulk=false, $customsequence=false) {
1300 if (!is_array($params)) {
1301 $params = (array)$params;
1304 if ($customsequence) {
1305 if (!isset($params['id'])) {
1306 throw new coding_exception('moodle_database::insert_record_raw() id field must be specified if custom sequences used.');
1310 unset($params['id']);
1313 if (empty($params)) {
1314 throw new coding_exception('moodle_database::insert_record_raw() no fields found.');
1317 $fields = implode(',', array_keys($params));
1318 $qms = array_fill(0, count($params), '?');
1319 $qms = implode(',', $qms);
1321 $sql = "INSERT INTO {$this->prefix}$table ($fields) VALUES($qms)";
1323 list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
1324 $rawsql = $this->emulate_bound_params($sql, $params);
1326 $this->query_start($sql, $params, SQL_QUERY_INSERT
);
1327 $result = $this->mysqli
->query($rawsql);
1328 $id = @$this->mysqli
->insert_id
; // must be called before query_end() which may insert log into db
1329 $this->query_end($result);
1331 if (!$customsequence and !$id) {
1332 throw new dml_write_exception('unknown error fetching inserted id');
1343 * Insert a record into a table and return the "id" field if required.
1345 * Some conversions and safety checks are carried out. Lobs are supported.
1346 * If the return ID isn't required, then this just reports success as true/false.
1347 * $data is an object containing needed data
1348 * @param string $table The database table to be inserted into
1349 * @param object $data A data object with values for one or more fields in the record
1350 * @param bool $returnid Should the id of the newly created record entry be returned? If this option is not requested then true/false is returned.
1351 * @return bool|int true or new id
1352 * @throws dml_exception A DML specific exception is thrown for any errors.
1354 public function insert_record($table, $dataobject, $returnid=true, $bulk=false) {
1355 $dataobject = (array)$dataobject;
1357 $columns = $this->get_columns($table);
1358 if (empty($columns)) {
1359 throw new dml_exception('ddltablenotexist', $table);
1364 foreach ($dataobject as $field=>$value) {
1365 if ($field === 'id') {
1368 if (!isset($columns[$field])) {
1371 $column = $columns[$field];
1372 $cleaned[$field] = $this->normalise_value($column, $value);
1375 return $this->insert_record_raw($table, $cleaned, $returnid, $bulk);
1379 * Insert multiple records into database as fast as possible.
1381 * Order of inserts is maintained, but the operation is not atomic,
1382 * use transactions if necessary.
1384 * This method is intended for inserting of large number of small objects,
1385 * do not use for huge objects with text or binary fields.
1389 * @param string $table The database table to be inserted into
1390 * @param array|Traversable $dataobjects list of objects to be inserted, must be compatible with foreach
1391 * @return void does not return new record ids
1393 * @throws coding_exception if data objects have different structure
1394 * @throws dml_exception A DML specific exception is thrown for any errors.
1396 public function insert_records($table, $dataobjects) {
1397 if (!is_array($dataobjects) and !$dataobjects instanceof Traversable
) {
1398 throw new coding_exception('insert_records() passed non-traversable object');
1401 // MySQL has a relatively small query length limit by default,
1402 // make sure 'max_allowed_packet' in my.cnf is high enough
1403 // if you change the following default...
1404 static $chunksize = null;
1405 if ($chunksize === null) {
1406 if (!empty($this->dboptions
['bulkinsertsize'])) {
1407 $chunksize = (int)$this->dboptions
['bulkinsertsize'];
1410 if (PHP_INT_SIZE
=== 4) {
1411 // Bad luck for Windows, we cannot do any maths with large numbers.
1414 $sql = "SHOW VARIABLES LIKE 'max_allowed_packet'";
1415 $this->query_start($sql, null, SQL_QUERY_AUX
);
1416 $result = $this->mysqli
->query($sql);
1417 $this->query_end($result);
1419 if ($rec = $result->fetch_assoc()) {
1420 $size = $rec['Value'];
1423 // Hopefully 200kb per object are enough.
1424 $chunksize = (int)($size / 200000);
1425 if ($chunksize > 50) {
1432 $columns = $this->get_columns($table, true);
1436 foreach ($dataobjects as $dataobject) {
1437 if (!is_array($dataobject) and !is_object($dataobject)) {
1438 throw new coding_exception('insert_records() passed invalid record object');
1440 $dataobject = (array)$dataobject;
1441 if ($fields === null) {
1442 $fields = array_keys($dataobject);
1443 $columns = array_intersect_key($columns, $dataobject);
1444 unset($columns['id']);
1445 } else if ($fields !== array_keys($dataobject)) {
1446 throw new coding_exception('All dataobjects in insert_records() must have the same structure!');
1450 $chunk[] = $dataobject;
1452 if ($count === $chunksize) {
1453 $this->insert_chunk($table, $chunk, $columns);
1460 $this->insert_chunk($table, $chunk, $columns);
1465 * Insert records in chunks.
1467 * Note: can be used only from insert_records().
1469 * @param string $table
1470 * @param array $chunk
1471 * @param database_column_info[] $columns
1473 protected function insert_chunk($table, array $chunk, array $columns) {
1474 $fieldssql = '('.implode(',', array_keys($columns)).')';
1476 $valuessql = '('.implode(',', array_fill(0, count($columns), '?')).')';
1477 $valuessql = implode(',', array_fill(0, count($chunk), $valuessql));
1480 foreach ($chunk as $dataobject) {
1481 foreach ($columns as $field => $column) {
1482 $params[] = $this->normalise_value($column, $dataobject[$field]);
1486 $sql = "INSERT INTO {$this->prefix}$table $fieldssql VALUES $valuessql";
1488 list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
1489 $rawsql = $this->emulate_bound_params($sql, $params);
1491 $this->query_start($sql, $params, SQL_QUERY_INSERT
);
1492 $result = $this->mysqli
->query($rawsql);
1493 $this->query_end($result);
1497 * Import a record into a table, id field is required.
1498 * Safety checks are NOT carried out. Lobs are supported.
1500 * @param string $table name of database table to be inserted into
1501 * @param object $dataobject A data object with values for one or more fields in the record
1503 * @throws dml_exception A DML specific exception is thrown for any errors.
1505 public function import_record($table, $dataobject) {
1506 $dataobject = (array)$dataobject;
1508 $columns = $this->get_columns($table);
1511 foreach ($dataobject as $field=>$value) {
1512 if (!isset($columns[$field])) {
1515 $cleaned[$field] = $value;
1518 return $this->insert_record_raw($table, $cleaned, false, true, true);
1522 * Update record in database, as fast as possible, no safety checks, lobs not supported.
1523 * @param string $table name
1524 * @param mixed $params data record as object or array
1525 * @param bool true means repeated updates expected
1527 * @throws dml_exception A DML specific exception is thrown for any errors.
1529 public function update_record_raw($table, $params, $bulk=false) {
1530 $params = (array)$params;
1532 if (!isset($params['id'])) {
1533 throw new coding_exception('moodle_database::update_record_raw() id field must be specified.');
1535 $id = $params['id'];
1536 unset($params['id']);
1538 if (empty($params)) {
1539 throw new coding_exception('moodle_database::update_record_raw() no fields found.');
1543 foreach ($params as $field=>$value) {
1544 $sets[] = "$field = ?";
1547 $params[] = $id; // last ? in WHERE condition
1549 $sets = implode(',', $sets);
1550 $sql = "UPDATE {$this->prefix}$table SET $sets WHERE id=?";
1552 list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
1553 $rawsql = $this->emulate_bound_params($sql, $params);
1555 $this->query_start($sql, $params, SQL_QUERY_UPDATE
);
1556 $result = $this->mysqli
->query($rawsql);
1557 $this->query_end($result);
1563 * Update a record in a table
1565 * $dataobject is an object containing needed data
1566 * Relies on $dataobject having a variable "id" to
1567 * specify the record to update
1569 * @param string $table The database table to be checked against.
1570 * @param object $dataobject An object with contents equal to fieldname=>fieldvalue. Must have an entry for 'id' to map to the table specified.
1571 * @param bool true means repeated updates expected
1573 * @throws dml_exception A DML specific exception is thrown for any errors.
1575 public function update_record($table, $dataobject, $bulk=false) {
1576 $dataobject = (array)$dataobject;
1578 $columns = $this->get_columns($table);
1581 foreach ($dataobject as $field=>$value) {
1582 if (!isset($columns[$field])) {
1585 $column = $columns[$field];
1586 $cleaned[$field] = $this->normalise_value($column, $value);
1589 return $this->update_record_raw($table, $cleaned, $bulk);
1593 * Set a single field in every table record which match a particular WHERE clause.
1595 * @param string $table The database table to be checked against.
1596 * @param string $newfield the field to set.
1597 * @param string $newvalue the value to set the field to.
1598 * @param string $select A fragment of SQL to be used in a where clause in the SQL call.
1599 * @param array $params array of sql parameters
1601 * @throws dml_exception A DML specific exception is thrown for any errors.
1603 public function set_field_select($table, $newfield, $newvalue, $select, array $params=null) {
1605 $select = "WHERE $select";
1607 if (is_null($params)) {
1610 list($select, $params, $type) = $this->fix_sql_params($select, $params);
1612 // Get column metadata
1613 $columns = $this->get_columns($table);
1614 $column = $columns[$newfield];
1616 $normalised_value = $this->normalise_value($column, $newvalue);
1618 if (is_null($normalised_value)) {
1619 $newfield = "$newfield = NULL";
1621 $newfield = "$newfield = ?";
1622 array_unshift($params, $normalised_value);
1624 $sql = "UPDATE {$this->prefix}$table SET $newfield $select";
1625 $rawsql = $this->emulate_bound_params($sql, $params);
1627 $this->query_start($sql, $params, SQL_QUERY_UPDATE
);
1628 $result = $this->mysqli
->query($rawsql);
1629 $this->query_end($result);
1635 * Delete one or more records from a table which match a particular WHERE clause.
1637 * @param string $table The database table to be checked against.
1638 * @param string $select A fragment of SQL to be used in a where clause in the SQL call (used to define the selection criteria).
1639 * @param array $params array of sql parameters
1641 * @throws dml_exception A DML specific exception is thrown for any errors.
1643 public function delete_records_select($table, $select, array $params=null) {
1645 $select = "WHERE $select";
1647 $sql = "DELETE FROM {$this->prefix}$table $select";
1649 list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
1650 $rawsql = $this->emulate_bound_params($sql, $params);
1652 $this->query_start($sql, $params, SQL_QUERY_UPDATE
);
1653 $result = $this->mysqli
->query($rawsql);
1654 $this->query_end($result);
1659 public function sql_cast_char2int($fieldname, $text=false) {
1660 return ' CAST(' . $fieldname . ' AS SIGNED) ';
1663 public function sql_cast_char2real($fieldname, $text=false) {
1664 // Set to 65 (max mysql 5.5 precision) with 7 as scale
1665 // because we must ensure at least 6 decimal positions
1666 // per casting given that postgres is casting to that scale (::real::).
1667 // Can be raised easily but that must be done in all DBs and tests.
1668 return ' CAST(' . $fieldname . ' AS DECIMAL(65,7)) ';
1671 public function sql_equal($fieldname, $param, $casesensitive = true, $accentsensitive = true, $notequal = false) {
1672 $equalop = $notequal ?
'<>' : '=';
1674 $collationinfo = explode('_', $this->get_dbcollation());
1675 $bincollate = reset($collationinfo) . '_bin';
1677 if ($casesensitive) {
1678 // Current MySQL versions do not support case sensitive and accent insensitive.
1679 return "$fieldname COLLATE $bincollate $equalop $param";
1680 } else if ($accentsensitive) {
1681 // Case insensitive and accent sensitive, we can force a binary comparison once all texts are using the same case.
1682 return "LOWER($fieldname) COLLATE $bincollate $equalop LOWER($param)";
1684 // Case insensitive and accent insensitive. All collations are that way, but utf8_bin.
1686 if ($this->get_dbcollation() == 'utf8_bin') {
1687 $collation = 'COLLATE utf8_unicode_ci';
1688 } else if ($this->get_dbcollation() == 'utf8mb4_bin') {
1689 $collation = 'COLLATE utf8mb4_unicode_ci';
1691 return "$fieldname $collation $equalop $param";
1696 * Returns 'LIKE' part of a query.
1698 * Note that mysql does not support $casesensitive = true and $accentsensitive = false.
1699 * More information in http://bugs.mysql.com/bug.php?id=19567.
1701 * @param string $fieldname usually name of the table column
1702 * @param string $param usually bound query parameter (?, :named)
1703 * @param bool $casesensitive use case sensitive search
1704 * @param bool $accensensitive use accent sensitive search (ignored if $casesensitive is true)
1705 * @param bool $notlike true means "NOT LIKE"
1706 * @param string $escapechar escape char for '%' and '_'
1707 * @return string SQL code fragment
1709 public function sql_like($fieldname, $param, $casesensitive = true, $accentsensitive = true, $notlike = false, $escapechar = '\\') {
1710 if (strpos($param, '%') !== false) {
1711 debugging('Potential SQL injection detected, sql_like() expects bound parameters (? or :named)');
1713 $escapechar = $this->mysqli
->real_escape_string($escapechar); // prevents problems with C-style escapes of enclosing '\'
1715 $collationinfo = explode('_', $this->get_dbcollation());
1716 $bincollate = reset($collationinfo) . '_bin';
1718 $LIKE = $notlike ?
'NOT LIKE' : 'LIKE';
1720 if ($casesensitive) {
1721 // Current MySQL versions do not support case sensitive and accent insensitive.
1722 return "$fieldname $LIKE $param COLLATE $bincollate ESCAPE '$escapechar'";
1724 } else if ($accentsensitive) {
1725 // Case insensitive and accent sensitive, we can force a binary comparison once all texts are using the same case.
1726 return "LOWER($fieldname) $LIKE LOWER($param) COLLATE $bincollate ESCAPE '$escapechar'";
1729 // Case insensitive and accent insensitive.
1731 if ($this->get_dbcollation() == 'utf8_bin') {
1732 // Force a case insensitive comparison if using utf8_bin.
1733 $collation = 'COLLATE utf8_unicode_ci';
1734 } else if ($this->get_dbcollation() == 'utf8mb4_bin') {
1735 // Force a case insensitive comparison if using utf8mb4_bin.
1736 $collation = 'COLLATE utf8mb4_unicode_ci';
1739 return "$fieldname $LIKE $param $collation ESCAPE '$escapechar'";
1744 * Returns the proper SQL to do CONCAT between the elements passed
1745 * Can take many parameters
1747 * @param string $str,... 1 or more fields/strings to concat
1749 * @return string The concat sql
1751 public function sql_concat() {
1752 $arr = func_get_args();
1753 $s = implode(', ', $arr);
1757 return "CONCAT($s)";
1761 * Returns the proper SQL to do CONCAT between the elements passed
1762 * with a given separator
1764 * @param string $separator The string to use as the separator
1765 * @param array $elements An array of items to concatenate
1766 * @return string The concat SQL
1768 public function sql_concat_join($separator="' '", $elements=array()) {
1769 $s = implode(', ', $elements);
1774 return "CONCAT_WS($separator, $s)";
1778 * Returns the SQL text to be used to calculate the length in characters of one expression.
1779 * @param string fieldname or expression to calculate its length in characters.
1780 * @return string the piece of SQL code to be used in the statement.
1782 public function sql_length($fieldname) {
1783 return ' CHAR_LENGTH(' . $fieldname . ')';
1787 * Does this driver support regex syntax when searching
1789 public function sql_regex_supported() {
1794 * Return regex positive or negative match sql
1795 * @param bool $positivematch
1796 * @param bool $casesensitive
1797 * @return string or empty if not supported
1799 public function sql_regex($positivematch = true, $casesensitive = false) {
1801 if ($casesensitive) {
1802 if (substr($this->get_dbcollation(), -4) !== '_bin') {
1803 $collationinfo = explode('_', $this->get_dbcollation());
1804 $collation = 'COLLATE ' . $collationinfo[0] . '_bin ';
1807 if ($this->get_dbcollation() == 'utf8_bin') {
1808 $collation = 'COLLATE utf8_unicode_ci ';
1809 } else if ($this->get_dbcollation() == 'utf8mb4_bin') {
1810 $collation = 'COLLATE utf8mb4_unicode_ci ';
1814 return $collation . ($positivematch ?
'REGEXP' : 'NOT REGEXP');
1818 * Returns the SQL to be used in order to an UNSIGNED INTEGER column to SIGNED.
1820 * @deprecated since 2.3
1821 * @param string $fieldname The name of the field to be cast
1822 * @return string The piece of SQL code to be used in your statement.
1824 public function sql_cast_2signed($fieldname) {
1825 return ' CAST(' . $fieldname . ' AS SIGNED) ';
1829 * Returns the SQL that allows to find intersection of two or more queries
1833 * @param array $selects array of SQL select queries, each of them only returns fields with the names from $fields
1834 * @param string $fields comma-separated list of fields
1835 * @return string SQL query that will return only values that are present in each of selects
1837 public function sql_intersect($selects, $fields) {
1838 if (count($selects) <= 1) {
1839 return parent
::sql_intersect($selects, $fields);
1841 $fields = preg_replace('/\s/', '', $fields);
1842 static $aliascnt = 0;
1843 $falias = 'intsctal'.($aliascnt++
);
1844 $rv = "SELECT $falias.".
1845 preg_replace('/,/', ','.$falias.'.', $fields).
1846 " FROM ($selects[0]) $falias";
1847 for ($i = 1; $i < count($selects); $i++
) {
1848 $alias = 'intsctal'.($aliascnt++
);
1849 $rv .= " JOIN (".$selects[$i].") $alias ON ".
1852 function($a) use ($alias, $falias) {
1853 return $falias . '.' . $a .' = ' . $alias . '.' . $a;
1855 preg_split('/,/', $fields))
1862 * Does this driver support tool_replace?
1864 * @since Moodle 2.6.1
1867 public function replace_all_text_supported() {
1871 public function session_lock_supported() {
1876 * Obtain session lock
1877 * @param int $rowid id of the row with session record
1878 * @param int $timeout max allowed time to wait for the lock in seconds
1881 public function get_session_lock($rowid, $timeout) {
1882 parent
::get_session_lock($rowid, $timeout);
1884 $fullname = $this->dbname
.'-'.$this->prefix
.'-session-'.$rowid;
1885 $sql = "SELECT GET_LOCK('$fullname', $timeout)";
1886 $this->query_start($sql, null, SQL_QUERY_AUX
);
1887 $result = $this->mysqli
->query($sql);
1888 $this->query_end($result);
1891 $arr = $result->fetch_assoc();
1894 if (reset($arr) == 1) {
1897 throw new dml_sessionwait_exception();
1902 public function release_session_lock($rowid) {
1903 if (!$this->used_for_db_sessions
) {
1907 parent
::release_session_lock($rowid);
1908 $fullname = $this->dbname
.'-'.$this->prefix
.'-session-'.$rowid;
1909 $sql = "SELECT RELEASE_LOCK('$fullname')";
1910 $this->query_start($sql, null, SQL_QUERY_AUX
);
1911 $result = $this->mysqli
->query($sql);
1912 $this->query_end($result);
1920 * Are transactions supported?
1921 * It is not responsible to run productions servers
1922 * on databases without transaction support ;-)
1924 * MyISAM does not support support transactions.
1926 * You can override this via the dbtransactions option.
1930 protected function transactions_supported() {
1931 if (!is_null($this->transactions_supported
)) {
1932 return $this->transactions_supported
;
1935 // this is all just guessing, might be better to just specify it in config.php
1936 if (isset($this->dboptions
['dbtransactions'])) {
1937 $this->transactions_supported
= $this->dboptions
['dbtransactions'];
1938 return $this->transactions_supported
;
1941 $this->transactions_supported
= false;
1943 $engine = $this->get_dbengine();
1945 // Only will accept transactions if using compatible storage engine (more engines can be added easily BDB, Falcon...)
1946 if (in_array($engine, array('InnoDB', 'INNOBASE', 'BDB', 'XtraDB', 'Aria', 'Falcon'))) {
1947 $this->transactions_supported
= true;
1950 return $this->transactions_supported
;
1954 * Driver specific start of real database transaction,
1955 * this can not be used directly in code.
1958 protected function begin_transaction() {
1959 if (!$this->transactions_supported()) {
1963 $sql = "SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED";
1964 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
1965 $result = $this->mysqli
->query($sql);
1966 $this->query_end($result);
1968 $sql = "START TRANSACTION";
1969 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
1970 $result = $this->mysqli
->query($sql);
1971 $this->query_end($result);
1975 * Driver specific commit of real database transaction,
1976 * this can not be used directly in code.
1979 protected function commit_transaction() {
1980 if (!$this->transactions_supported()) {
1985 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
1986 $result = $this->mysqli
->query($sql);
1987 $this->query_end($result);
1991 * Driver specific abort of real database transaction,
1992 * this can not be used directly in code.
1995 protected function rollback_transaction() {
1996 if (!$this->transactions_supported()) {
2001 $this->query_start($sql, NULL, SQL_QUERY_AUX
);
2002 $result = $this->mysqli
->query($sql);
2003 $this->query_end($result);
2009 * Converts a table to either 'Compressed' or 'Dynamic' row format.
2011 * @param string $tablename Name of the table to convert to the new row format.
2013 public function convert_table_row_format($tablename) {
2014 $currentrowformat = $this->get_row_format($tablename);
2015 if ($currentrowformat == 'Compact' ||
$currentrowformat == 'Redundant') {
2016 $rowformat = ($this->is_compressed_row_format_supported(false)) ?
"ROW_FORMAT=Compressed" : "ROW_FORMAT=Dynamic";
2017 $prefix = $this->get_prefix();
2018 $this->change_database_structure("ALTER TABLE {$prefix}$tablename $rowformat");
2023 * Does this mysql instance support fulltext indexes?
2027 public function is_fulltext_search_supported() {
2028 $info = $this->get_server_info();
2030 if (version_compare($info['version'], '5.6.4', '>=')) {