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1 <?php 2 // This file is part of Moodle - http://moodle.org/ 3 // 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. 8 // 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. 13 // 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/>. 16 17 /** 18 * Native oci class representing moodle database interface. 19 * 20 * @package core_dml 21 * @copyright 2008 Petr Skoda (http://skodak.org) 22 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 23 */ 24 25 defined('MOODLE_INTERNAL') || die(); 26 27 require_once (__DIR__.'/moodle_database.php'); 28 require_once (__DIR__.'/oci_native_moodle_recordset.php'); 29 require_once (__DIR__.'/oci_native_moodle_temptables.php'); 30 31 /** 32 * Native oci class representing moodle database interface. 33 * 34 * One complete reference for PHP + OCI: 35 * http://www.oracle.com/technology/tech/php/underground-php-oracle-manual.html 36 * 37 * @package core_dml 38 * @copyright 2008 Petr Skoda (http://skodak.org) 39 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 40 */ 41 class oci_native_moodle_database extends moodle_database { 42 43 protected $oci = null; 44 45 /** @var To store stmt errors and enable get_last_error() to detect them.*/ 46 private $last_stmt_error = null; 47 /** @var Default value initialised in connect method, we need the driver to be present.*/ 48 private $commit_status = null; 49 50 /** @var To handle oci driver default verbosity.*/ 51 private $last_error_reporting; 52 /** @var To store unique_session_id. Needed for temp tables unique naming.*/ 53 private $unique_session_id; 54 55 /** 56 * Detects if all needed PHP stuff installed. 57 * Note: can be used before connect() 58 * @return mixed true if ok, string if something 59 */ 60 public function driver_installed() { 61 if (!extension_loaded('oci8')) { 62 return get_string('ociextensionisnotpresentinphp', 'install'); 63 } 64 return true; 65 } 66 67 /** 68 * Returns database family type - describes SQL dialect 69 * Note: can be used before connect() 70 * @return string db family name (mysql, postgres, mssql, oracle, etc.) 71 */ 72 public function get_dbfamily() { 73 return 'oracle'; 74 } 75 76 /** 77 * Returns more specific database driver type 78 * Note: can be used before connect() 79 * @return string db type mysqli, pgsql, oci, mssql, sqlsrv 80 */ 81 protected function get_dbtype() { 82 return 'oci'; 83 } 84 85 /** 86 * Returns general database library name 87 * Note: can be used before connect() 88 * @return string db type pdo, native 89 */ 90 protected function get_dblibrary() { 91 return 'native'; 92 } 93 94 /** 95 * Returns localised database type name 96 * Note: can be used before connect() 97 * @return string 98 */ 99 public function get_name() { 100 return get_string('nativeoci', 'install'); 101 } 102 103 /** 104 * Returns localised database configuration help. 105 * Note: can be used before connect() 106 * @return string 107 */ 108 public function get_configuration_help() { 109 return get_string('nativeocihelp', 'install'); 110 } 111 112 /** 113 * Diagnose database and tables, this function is used 114 * to verify database and driver settings, db engine types, etc. 115 * 116 * @return string null means everything ok, string means problem found. 117 */ 118 public function diagnose() { 119 return null; 120 } 121 122 /** 123 * Connect to db 124 * Must be called before other methods. 125 * @param string $dbhost The database host. 126 * @param string $dbuser The database username. 127 * @param string $dbpass The database username's password. 128 * @param string $dbname The name of the database being connected to. 129 * @param mixed $prefix string means moodle db prefix, false used for external databases where prefix not used 130 * @param array $dboptions driver specific options 131 * @return bool true 132 * @throws dml_connection_exception if error 133 */ 134 public function connect($dbhost, $dbuser, $dbpass, $dbname, $prefix, array $dboptions=null) { 135 if ($prefix == '' and !$this->external) { 136 //Enforce prefixes for everybody but mysql 137 throw new dml_exception('prefixcannotbeempty', $this->get_dbfamily()); 138 } 139 if (!$this->external and strlen($prefix) > 2) { 140 //Max prefix length for Oracle is 2cc 141 $a = (object)array('dbfamily'=>'oracle', 'maxlength'=>2); 142 throw new dml_exception('prefixtoolong', $a); 143 } 144 145 $driverstatus = $this->driver_installed(); 146 147 if ($driverstatus !== true) { 148 throw new dml_exception('dbdriverproblem', $driverstatus); 149 } 150 151 // Autocommit ON by default. 152 // Switching to OFF (OCI_DEFAULT), when playing with transactions 153 // please note this thing is not defined if oracle driver not present in PHP 154 // which means it can not be used as default value of object property! 155 $this->commit_status = OCI_COMMIT_ON_SUCCESS; 156 157 $this->store_settings($dbhost, $dbuser, $dbpass, $dbname, $prefix, $dboptions); 158 unset($this->dboptions['dbsocket']); 159 160 // NOTE: use of ', ", / and \ is very problematic, even native oracle tools seem to have 161 // problems with these, so just forget them and do not report problems into tracker... 162 163 if (empty($this->dbhost)) { 164 // old style full address (TNS) 165 $dbstring = $this->dbname; 166 } else { 167 if (empty($this->dboptions['dbport'])) { 168 $this->dboptions['dbport'] = 1521; 169 } 170 $dbstring = '//'.$this->dbhost.':'.$this->dboptions['dbport'].'/'.$this->dbname; 171 } 172 173 ob_start(); 174 if (empty($this->dboptions['dbpersist'])) { 175 $this->oci = oci_new_connect($this->dbuser, $this->dbpass, $dbstring, 'AL32UTF8'); 176 } else { 177 $this->oci = oci_pconnect($this->dbuser, $this->dbpass, $dbstring, 'AL32UTF8'); 178 } 179 $dberr = ob_get_contents(); 180 ob_end_clean(); 181 182 183 if ($this->oci === false) { 184 $this->oci = null; 185 $e = oci_error(); 186 if (isset($e['message'])) { 187 $dberr = $e['message']; 188 } 189 throw new dml_connection_exception($dberr); 190 } 191 192 // Make sure moodle package is installed - now required. 193 if (!$this->oci_package_installed()) { 194 try { 195 $this->attempt_oci_package_install(); 196 } catch (Exception $e) { 197 // Ignore problems, only the result counts, 198 // admins have to fix it manually if necessary. 199 } 200 if (!$this->oci_package_installed()) { 201 throw new dml_exception('dbdriverproblem', 'Oracle PL/SQL Moodle support package MOODLELIB is not installed! Database administrator has to execute /lib/dml/oci_native_moodle_package.sql script.'); 202 } 203 } 204 205 // get unique session id, to be used later for temp tables stuff 206 $sql = 'SELECT DBMS_SESSION.UNIQUE_SESSION_ID() FROM DUAL'; 207 $this->query_start($sql, null, SQL_QUERY_AUX); 208 $stmt = $this->parse_query($sql); 209 $result = oci_execute($stmt, $this->commit_status); 210 $this->query_end($result, $stmt); 211 $records = null; 212 oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_ROW); 213 oci_free_statement($stmt); 214 $this->unique_session_id = reset($records[0]); 215 216 //note: do not send "ALTER SESSION SET NLS_NUMERIC_CHARACTERS='.,'" ! 217 // instead fix our PHP code to convert "," to "." properly! 218 219 // Connection stabilised and configured, going to instantiate the temptables controller 220 $this->temptables = new oci_native_moodle_temptables($this, $this->unique_session_id); 221 222 return true; 223 } 224 225 /** 226 * Close database connection and release all resources 227 * and memory (especially circular memory references). 228 * Do NOT use connect() again, create a new instance if needed. 229 */ 230 public function dispose() { 231 parent::dispose(); // Call parent dispose to write/close session and other common stuff before closing connection 232 if ($this->oci) { 233 oci_close($this->oci); 234 $this->oci = null; 235 } 236 } 237 238 239 /** 240 * Called before each db query. 241 * @param string $sql 242 * @param array array of parameters 243 * @param int $type type of query 244 * @param mixed $extrainfo driver specific extra information 245 * @return void 246 */ 247 protected function query_start($sql, array $params=null, $type, $extrainfo=null) { 248 parent::query_start($sql, $params, $type, $extrainfo); 249 // oci driver tents to send debug to output, we do not need that ;-) 250 $this->last_error_reporting = error_reporting(0); 251 } 252 253 /** 254 * Called immediately after each db query. 255 * @param mixed db specific result 256 * @return void 257 */ 258 protected function query_end($result, $stmt=null) { 259 // reset original debug level 260 error_reporting($this->last_error_reporting); 261 if ($stmt and $result === false) { 262 // Look for stmt error and store it 263 if (is_resource($stmt)) { 264 $e = oci_error($stmt); 265 if ($e !== false) { 266 $this->last_stmt_error = $e['message']; 267 } 268 } 269 oci_free_statement($stmt); 270 } 271 parent::query_end($result); 272 } 273 274 /** 275 * Returns database server info array 276 * @return array Array containing 'description' and 'version' info 277 */ 278 public function get_server_info() { 279 static $info = null; // TODO: move to real object property 280 281 if (is_null($info)) { 282 $this->query_start("--oci_server_version()", null, SQL_QUERY_AUX); 283 $description = oci_server_version($this->oci); 284 $this->query_end(true); 285 preg_match('/(\d+\.)+\d+/', $description, $matches); 286 $info = array('description'=>$description, 'version'=>$matches[0]); 287 } 288 289 return $info; 290 } 291 292 /** 293 * Converts short table name {tablename} to real table name 294 * supporting temp tables ($this->unique_session_id based) if detected 295 * 296 * @param string sql 297 * @return string sql 298 */ 299 protected function fix_table_names($sql) { 300 if (preg_match_all('/\{([a-z][a-z0-9_]*)\}/', $sql, $matches)) { 301 foreach($matches[0] as $key=>$match) { 302 $name = $matches[1][$key]; 303 if ($this->temptables && $this->temptables->is_temptable($name)) { 304 $sql = str_replace($match, $this->temptables->get_correct_name($name), $sql); 305 } else { 306 $sql = str_replace($match, $this->prefix.$name, $sql); 307 } 308 } 309 } 310 return $sql; 311 } 312 313 /** 314 * Returns supported query parameter types 315 * @return int bitmask of accepted SQL_PARAMS_* 316 */ 317 protected function allowed_param_types() { 318 return SQL_PARAMS_NAMED; 319 } 320 321 /** 322 * Returns last error reported by database engine. 323 * @return string error message 324 */ 325 public function get_last_error() { 326 $error = false; 327 // First look for any previously saved stmt error 328 if (!empty($this->last_stmt_error)) { 329 $error = $this->last_stmt_error; 330 $this->last_stmt_error = null; 331 } else { // Now try connection error 332 $e = oci_error($this->oci); 333 if ($e !== false) { 334 $error = $e['message']; 335 } 336 } 337 return $error; 338 } 339 340 /** 341 * Prepare the statement for execution 342 * @throws dml_connection_exception 343 * @param string $sql 344 * @return resource 345 */ 346 protected function parse_query($sql) { 347 $stmt = oci_parse($this->oci, $sql); 348 if ($stmt == false) { 349 throw new dml_connection_exception('Can not parse sql query'); //TODO: maybe add better info 350 } 351 return $stmt; 352 } 353 354 /** 355 * Make sure there are no reserved words in param names... 356 * @param string $sql 357 * @param array $params 358 * @return array ($sql, $params) updated query and parameters 359 */ 360 protected function tweak_param_names($sql, array $params) { 361 if (empty($params)) { 362 return array($sql, $params); 363 } 364 365 $newparams = array(); 366 $searcharr = array(); // search => replace pairs 367 foreach ($params as $name => $value) { 368 // Keep the name within the 30 chars limit always (prefixing/replacing) 369 if (strlen($name) <= 28) { 370 $newname = 'o_' . $name; 371 } else { 372 $newname = 'o_' . substr($name, 2); 373 } 374 $newparams[$newname] = $value; 375 $searcharr[':' . $name] = ':' . $newname; 376 } 377 // sort by length desc to avoid potential str_replace() overlap 378 uksort($searcharr, array('oci_native_moodle_database', 'compare_by_length_desc')); 379 380 $sql = str_replace(array_keys($searcharr), $searcharr, $sql); 381 return array($sql, $newparams); 382 } 383 384 /** 385 * Return tables in database WITHOUT current prefix 386 * @param bool $usecache if true, returns list of cached tables. 387 * @return array of table names in lowercase and without prefix 388 */ 389 public function get_tables($usecache=true) { 390 if ($usecache and $this->tables !== null) { 391 return $this->tables; 392 } 393 $this->tables = array(); 394 $prefix = str_replace('_', "\\_", strtoupper($this->prefix)); 395 $sql = "SELECT TABLE_NAME 396 FROM CAT 397 WHERE TABLE_TYPE='TABLE' 398 AND TABLE_NAME NOT LIKE 'BIN\$%' 399 AND TABLE_NAME LIKE '$prefix%' ESCAPE '\\'"; 400 $this->query_start($sql, null, SQL_QUERY_AUX); 401 $stmt = $this->parse_query($sql); 402 $result = oci_execute($stmt, $this->commit_status); 403 $this->query_end($result, $stmt); 404 $records = null; 405 oci_fetch_all($stmt, $records, 0, -1, OCI_ASSOC); 406 oci_free_statement($stmt); 407 $records = array_map('strtolower', $records['TABLE_NAME']); 408 foreach ($records as $tablename) { 409 if ($this->prefix !== false && $this->prefix !== '') { 410 if (strpos($tablename, $this->prefix) !== 0) { 411 continue; 412 } 413 $tablename = substr($tablename, strlen($this->prefix)); 414 } 415 $this->tables[$tablename] = $tablename; 416 } 417 418 // Add the currently available temptables 419 $this->tables = array_merge($this->tables, $this->temptables->get_temptables()); 420 421 return $this->tables; 422 } 423 424 /** 425 * Return table indexes - everything lowercased. 426 * @param string $table The table we want to get indexes from. 427 * @return array An associative array of indexes containing 'unique' flag and 'columns' being indexed 428 */ 429 public function get_indexes($table) { 430 $indexes = array(); 431 $tablename = strtoupper($this->prefix.$table); 432 433 $sql = "SELECT i.INDEX_NAME, i.UNIQUENESS, c.COLUMN_POSITION, c.COLUMN_NAME, ac.CONSTRAINT_TYPE 434 FROM ALL_INDEXES i 435 JOIN ALL_IND_COLUMNS c ON c.INDEX_NAME=i.INDEX_NAME 436 LEFT JOIN ALL_CONSTRAINTS ac ON (ac.TABLE_NAME=i.TABLE_NAME AND ac.CONSTRAINT_NAME=i.INDEX_NAME AND ac.CONSTRAINT_TYPE='P') 437 WHERE i.TABLE_NAME = '$tablename' 438 ORDER BY i.INDEX_NAME, c.COLUMN_POSITION"; 439 440 $stmt = $this->parse_query($sql); 441 $result = oci_execute($stmt, $this->commit_status); 442 $this->query_end($result, $stmt); 443 $records = null; 444 oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_ROW); 445 oci_free_statement($stmt); 446 447 foreach ($records as $record) { 448 if ($record['CONSTRAINT_TYPE'] === 'P') { 449 //ignore for now; 450 continue; 451 } 452 $indexname = strtolower($record['INDEX_NAME']); 453 if (!isset($indexes[$indexname])) { 454 $indexes[$indexname] = array('primary' => ($record['CONSTRAINT_TYPE'] === 'P'), 455 'unique' => ($record['UNIQUENESS'] === 'UNIQUE'), 456 'columns' => array()); 457 } 458 $indexes[$indexname]['columns'][] = strtolower($record['COLUMN_NAME']); 459 } 460 461 return $indexes; 462 } 463 464 /** 465 * Returns detailed information about columns in table. This information is cached internally. 466 * @param string $table name 467 * @param bool $usecache 468 * @return array array of database_column_info objects indexed with column names 469 */ 470 public function get_columns($table, $usecache=true) { 471 472 if ($usecache) { 473 if ($this->temptables->is_temptable($table)) { 474 if ($data = $this->get_temp_tables_cache()->get($table)) { 475 return $data; 476 } 477 } else { 478 if ($data = $this->get_metacache()->get($table)) { 479 return $data; 480 } 481 } 482 } 483 484 if (!$table) { // table not specified, return empty array directly 485 return array(); 486 } 487 488 $structure = array(); 489 490 // We give precedence to CHAR_LENGTH for VARCHAR2 columns over WIDTH because the former is always 491 // BYTE based and, for cross-db operations, we want CHAR based results. See MDL-29415 492 // Instead of guessing sequence based exclusively on name, check tables against user_triggers to 493 // ensure the table has a 'before each row' trigger to assume 'id' is auto_increment. MDL-32365 494 $sql = "SELECT CNAME, COLTYPE, nvl(CHAR_LENGTH, WIDTH) AS WIDTH, SCALE, PRECISION, NULLS, DEFAULTVAL, 495 DECODE(NVL(TRIGGER_NAME, '0'), '0', '0', '1') HASTRIGGER 496 FROM COL c 497 LEFT JOIN USER_TAB_COLUMNS u ON (u.TABLE_NAME = c.TNAME AND u.COLUMN_NAME = c.CNAME AND u.DATA_TYPE = 'VARCHAR2') 498 LEFT JOIN USER_TRIGGERS t ON (t.TABLE_NAME = c.TNAME AND TRIGGER_TYPE = 'BEFORE EACH ROW' AND c.CNAME = 'ID') 499 WHERE TNAME = UPPER('{" . $table . "}') 500 ORDER BY COLNO"; 501 502 list($sql, $params, $type) = $this->fix_sql_params($sql, null); 503 504 $this->query_start($sql, null, SQL_QUERY_AUX); 505 $stmt = $this->parse_query($sql); 506 $result = oci_execute($stmt, $this->commit_status); 507 $this->query_end($result, $stmt); 508 $records = null; 509 oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_ROW); 510 oci_free_statement($stmt); 511 512 if (!$records) { 513 return array(); 514 } 515 foreach ($records as $rawcolumn) { 516 $rawcolumn = (object)$rawcolumn; 517 518 $info = new stdClass(); 519 $info->name = strtolower($rawcolumn->CNAME); 520 $info->auto_increment = ((int)$rawcolumn->HASTRIGGER) ? true : false; 521 $matches = null; 522 523 if ($rawcolumn->COLTYPE === 'VARCHAR2' 524 or $rawcolumn->COLTYPE === 'VARCHAR' 525 or $rawcolumn->COLTYPE === 'NVARCHAR2' 526 or $rawcolumn->COLTYPE === 'NVARCHAR' 527 or $rawcolumn->COLTYPE === 'CHAR' 528 or $rawcolumn->COLTYPE === 'NCHAR') { 529 $info->type = $rawcolumn->COLTYPE; 530 $info->meta_type = 'C'; 531 $info->max_length = $rawcolumn->WIDTH; 532 $info->scale = null; 533 $info->not_null = ($rawcolumn->NULLS === 'NOT NULL'); 534 $info->has_default = !is_null($rawcolumn->DEFAULTVAL); 535 if ($info->has_default) { 536 537 // this is hacky :-( 538 if ($rawcolumn->DEFAULTVAL === 'NULL') { 539 $info->default_value = null; 540 } else if ($rawcolumn->DEFAULTVAL === "' ' ") { // Sometimes it's stored with trailing space 541 $info->default_value = ""; 542 } else if ($rawcolumn->DEFAULTVAL === "' '") { // Sometimes it's stored without trailing space 543 $info->default_value = ""; 544 } else { 545 $info->default_value = trim($rawcolumn->DEFAULTVAL); // remove trailing space 546 $info->default_value = substr($info->default_value, 1, strlen($info->default_value)-2); //trim '' 547 } 548 } else { 549 $info->default_value = null; 550 } 551 $info->primary_key = false; 552 $info->binary = false; 553 $info->unsigned = null; 554 $info->unique = null; 555 556 } else if ($rawcolumn->COLTYPE === 'NUMBER') { 557 $info->type = $rawcolumn->COLTYPE; 558 $info->max_length = $rawcolumn->PRECISION; 559 $info->binary = false; 560 if (!is_null($rawcolumn->SCALE) && $rawcolumn->SCALE == 0) { // null in oracle scale allows decimals => not integer 561 // integer 562 if ($info->name === 'id') { 563 $info->primary_key = true; 564 $info->meta_type = 'R'; 565 $info->unique = true; 566 $info->has_default = false; 567 } else { 568 $info->primary_key = false; 569 $info->meta_type = 'I'; 570 $info->unique = null; 571 } 572 $info->scale = 0; 573 574 } else { 575 //float 576 $info->meta_type = 'N'; 577 $info->primary_key = false; 578 $info->unsigned = null; 579 $info->unique = null; 580 $info->scale = $rawcolumn->SCALE; 581 } 582 $info->not_null = ($rawcolumn->NULLS === 'NOT NULL'); 583 $info->has_default = !is_null($rawcolumn->DEFAULTVAL); 584 if ($info->has_default) { 585 $info->default_value = trim($rawcolumn->DEFAULTVAL); // remove trailing space 586 } else { 587 $info->default_value = null; 588 } 589 590 } else if ($rawcolumn->COLTYPE === 'FLOAT') { 591 $info->type = $rawcolumn->COLTYPE; 592 $info->max_length = (int)($rawcolumn->PRECISION * 3.32193); 593 $info->primary_key = false; 594 $info->meta_type = 'N'; 595 $info->unique = null; 596 $info->not_null = ($rawcolumn->NULLS === 'NOT NULL'); 597 $info->has_default = !is_null($rawcolumn->DEFAULTVAL); 598 if ($info->has_default) { 599 $info->default_value = trim($rawcolumn->DEFAULTVAL); // remove trailing space 600 } else { 601 $info->default_value = null; 602 } 603 604 } else if ($rawcolumn->COLTYPE === 'CLOB' 605 or $rawcolumn->COLTYPE === 'NCLOB') { 606 $info->type = $rawcolumn->COLTYPE; 607 $info->meta_type = 'X'; 608 $info->max_length = -1; 609 $info->scale = null; 610 $info->scale = null; 611 $info->not_null = ($rawcolumn->NULLS === 'NOT NULL'); 612 $info->has_default = !is_null($rawcolumn->DEFAULTVAL); 613 if ($info->has_default) { 614 // this is hacky :-( 615 if ($rawcolumn->DEFAULTVAL === 'NULL') { 616 $info->default_value = null; 617 } else if ($rawcolumn->DEFAULTVAL === "' ' ") { // Sometimes it's stored with trailing space 618 $info->default_value = ""; 619 } else if ($rawcolumn->DEFAULTVAL === "' '") { // Other times it's stored without trailing space 620 $info->default_value = ""; 621 } else { 622 $info->default_value = trim($rawcolumn->DEFAULTVAL); // remove trailing space 623 $info->default_value = substr($info->default_value, 1, strlen($info->default_value)-2); //trim '' 624 } 625 } else { 626 $info->default_value = null; 627 } 628 $info->primary_key = false; 629 $info->binary = false; 630 $info->unsigned = null; 631 $info->unique = null; 632 633 } else if ($rawcolumn->COLTYPE === 'BLOB') { 634 $info->type = $rawcolumn->COLTYPE; 635 $info->meta_type = 'B'; 636 $info->max_length = -1; 637 $info->scale = null; 638 $info->scale = null; 639 $info->not_null = ($rawcolumn->NULLS === 'NOT NULL'); 640 $info->has_default = !is_null($rawcolumn->DEFAULTVAL); 641 if ($info->has_default) { 642 // this is hacky :-( 643 if ($rawcolumn->DEFAULTVAL === 'NULL') { 644 $info->default_value = null; 645 } else if ($rawcolumn->DEFAULTVAL === "' ' ") { // Sometimes it's stored with trailing space 646 $info->default_value = ""; 647 } else if ($rawcolumn->DEFAULTVAL === "' '") { // Sometimes it's stored without trailing space 648 $info->default_value = ""; 649 } else { 650 $info->default_value = trim($rawcolumn->DEFAULTVAL); // remove trailing space 651 $info->default_value = substr($info->default_value, 1, strlen($info->default_value)-2); //trim '' 652 } 653 } else { 654 $info->default_value = null; 655 } 656 $info->primary_key = false; 657 $info->binary = true; 658 $info->unsigned = null; 659 $info->unique = null; 660 661 } else { 662 // unknown type - sorry 663 $info->type = $rawcolumn->COLTYPE; 664 $info->meta_type = '?'; 665 } 666 667 $structure[$info->name] = new database_column_info($info); 668 } 669 670 if ($usecache) { 671 if ($this->temptables->is_temptable($table)) { 672 $this->get_temp_tables_cache()->set($table, $structure); 673 } else { 674 $this->get_metacache()->set($table, $structure); 675 } 676 } 677 678 return $structure; 679 } 680 681 /** 682 * Normalise values based in RDBMS dependencies (booleans, LOBs...) 683 * 684 * @param database_column_info $column column metadata corresponding with the value we are going to normalise 685 * @param mixed $value value we are going to normalise 686 * @return mixed the normalised value 687 */ 688 protected function normalise_value($column, $value) { 689 $this->detect_objects($value); 690 691 if (is_bool($value)) { // Always, convert boolean to int 692 $value = (int)$value; 693 694 } else if ($column->meta_type == 'B') { // BLOB detected, we return 'blob' array instead of raw value to allow 695 if (!is_null($value)) { // binding/executing code later to know about its nature 696 $value = array('blob' => $value); 697 } 698 699 } else if ($column->meta_type == 'X' && strlen($value) > 4000) { // CLOB detected (>4000 optimisation), we return 'clob' 700 if (!is_null($value)) { // array instead of raw value to allow binding/ 701 $value = array('clob' => (string)$value); // executing code later to know about its nature 702 } 703 704 } else if ($value === '') { 705 if ($column->meta_type == 'I' or $column->meta_type == 'F' or $column->meta_type == 'N') { 706 $value = 0; // prevent '' problems in numeric fields 707 } 708 } 709 return $value; 710 } 711 712 /** 713 * Transforms the sql and params in order to emulate the LIMIT clause available in other DBs 714 * 715 * @param string $sql the SQL select query to execute. 716 * @param array $params array of sql parameters 717 * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set). 718 * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set). 719 * @return array with the transformed sql and params updated 720 */ 721 private function get_limit_sql($sql, array $params = null, $limitfrom=0, $limitnum=0) { 722 723 list($limitfrom, $limitnum) = $this->normalise_limit_from_num($limitfrom, $limitnum); 724 // TODO: Add the /*+ FIRST_ROWS */ hint if there isn't another hint 725 726 if ($limitfrom and $limitnum) { 727 $sql = "SELECT oracle_o.* 728 FROM (SELECT oracle_i.*, rownum AS oracle_rownum 729 FROM ($sql) oracle_i 730 WHERE rownum <= :oracle_num_rows 731 ) oracle_o 732 WHERE oracle_rownum > :oracle_skip_rows"; 733 $params['oracle_num_rows'] = $limitfrom + $limitnum; 734 $params['oracle_skip_rows'] = $limitfrom; 735 736 } else if ($limitfrom and !$limitnum) { 737 $sql = "SELECT oracle_o.* 738 FROM (SELECT oracle_i.*, rownum AS oracle_rownum 739 FROM ($sql) oracle_i 740 ) oracle_o 741 WHERE oracle_rownum > :oracle_skip_rows"; 742 $params['oracle_skip_rows'] = $limitfrom; 743 744 } else if (!$limitfrom and $limitnum) { 745 $sql = "SELECT * 746 FROM ($sql) 747 WHERE rownum <= :oracle_num_rows"; 748 $params['oracle_num_rows'] = $limitnum; 749 } 750 751 return array($sql, $params); 752 } 753 754 /** 755 * This function will handle all the column values before being inserted/updated to DB for Oracle 756 * installations. This is because the "special feature" of Oracle where the empty string is 757 * equal to NULL and this presents a problem with all our currently NOT NULL default '' fields. 758 * (and with empties handling in general) 759 * 760 * Note that this function is 100% private and should be used, exclusively by DML functions 761 * in this file. Also, this is considered a DIRTY HACK to be removed when possible. 762 * 763 * This function is private and must not be used outside this driver at all 764 * 765 * @param $table string the table where the record is going to be inserted/updated (without prefix) 766 * @param $field string the field where the record is going to be inserted/updated 767 * @param $value mixed the value to be inserted/updated 768 */ 769 private function oracle_dirty_hack ($table, $field, $value) { 770 771 // General bound parameter, just hack the spaces and pray it will work. 772 if (!$table) { 773 if ($value === '') { 774 return ' '; 775 } else if (is_bool($value)) { 776 return (int)$value; 777 } else { 778 return $value; 779 } 780 } 781 782 // Get metadata 783 $columns = $this->get_columns($table); 784 if (!isset($columns[$field])) { 785 if ($value === '') { 786 return ' '; 787 } else if (is_bool($value)) { 788 return (int)$value; 789 } else { 790 return $value; 791 } 792 } 793 $column = $columns[$field]; 794 795 // !! This paragraph explains behaviour before Moodle 2.0: 796 // 797 // For Oracle DB, empty strings are converted to NULLs in DB 798 // and this breaks a lot of NOT NULL columns currently Moodle. In the future it's 799 // planned to move some of them to NULL, if they must accept empty values and this 800 // piece of code will become less and less used. But, for now, we need it. 801 // What we are going to do is to examine all the data being inserted and if it's 802 // an empty string (NULL for Oracle) and the field is defined as NOT NULL, we'll modify 803 // such data in the best form possible ("0" for booleans and numbers and " " for the 804 // rest of strings. It isn't optimal, but the only way to do so. 805 // In the opposite, when retrieving records from Oracle, we'll decode " " back to 806 // empty strings to allow everything to work properly. DIRTY HACK. 807 808 // !! These paragraphs explain the rationale about the change for Moodle 2.5: 809 // 810 // Before Moodle 2.0, we only used to apply this DIRTY HACK to NOT NULL columns, as 811 // stated above, but it causes one problem in NULL columns where both empty strings 812 // and real NULLs are stored as NULLs, being impossible to differentiate them when 813 // being retrieved from DB. 814 // 815 // So, starting with Moodle 2.0, we are going to apply the DIRTY HACK to all the 816 // CHAR/CLOB columns no matter of their nullability. That way, when retrieving 817 // NULLABLE fields we'll get proper empties and NULLs differentiated, so we'll be able 818 // to rely in NULL/empty/content contents without problems, until now that wasn't 819 // possible at all. 820 // 821 // One space DIRTY HACK is now applied automatically for all query parameters 822 // and results. The only problem is string concatenation where the glue must 823 // be specified as "' '" sql fragment. 824 // 825 // !! Conclusions: 826 // 827 // From Moodle 2.5 onwards, ALL empty strings in Oracle DBs will be stored as 828 // 1-whitespace char, ALL NULLs as NULLs and, obviously, content as content. And 829 // those 1-whitespace chars will be converted back to empty strings by all the 830 // get_field/record/set() functions transparently and any SQL needing direct handling 831 // of empties will have to use placeholders or sql_isempty() helper function. 832 833 // If the field isn't VARCHAR or CLOB, skip 834 if ($column->meta_type != 'C' and $column->meta_type != 'X') { 835 return $value; 836 } 837 838 // If the value isn't empty, skip 839 if (!empty($value)) { 840 return $value; 841 } 842 843 // Now, we have one empty value, going to be inserted to one VARCHAR2 or CLOB field 844 // Try to get the best value to be inserted 845 846 // The '0' string doesn't need any transformation, skip 847 if ($value === '0') { 848 return $value; 849 } 850 851 // Transformations start 852 if (gettype($value) == 'boolean') { 853 return '0'; // Transform false to '0' that evaluates the same for PHP 854 855 } else if (gettype($value) == 'integer') { 856 return '0'; // Transform 0 to '0' that evaluates the same for PHP 857 858 } else if ($value === '') { 859 return ' '; // Transform '' to ' ' that DON'T EVALUATE THE SAME 860 // (we'll transform back again on get_records_XXX functions and others)!! 861 } 862 863 // Fail safe to original value 864 return $value; 865 } 866 867 /** 868 * Helper function to order by string length desc 869 * 870 * @param $a string first element to compare 871 * @param $b string second element to compare 872 * @return int < 0 $a goes first (is less), 0 $b goes first, 0 doesn't matter 873 */ 874 private function compare_by_length_desc($a, $b) { 875 return strlen($b) - strlen($a); 876 } 877 878 /** 879 * Is db in unicode mode? 880 * @return bool 881 */ 882 public function setup_is_unicodedb() { 883 $sql = "SELECT VALUE 884 FROM NLS_DATABASE_PARAMETERS 885 WHERE PARAMETER = 'NLS_CHARACTERSET'"; 886 $this->query_start($sql, null, SQL_QUERY_AUX); 887 $stmt = $this->parse_query($sql); 888 $result = oci_execute($stmt, $this->commit_status); 889 $this->query_end($result, $stmt); 890 $records = null; 891 oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_COLUMN); 892 oci_free_statement($stmt); 893 894 return (isset($records['VALUE'][0]) and $records['VALUE'][0] === 'AL32UTF8'); 895 } 896 897 /** 898 * Do NOT use in code, to be used by database_manager only! 899 * @param string|array $sql query 900 * @param array|null $tablenames an array of xmldb table names affected by this request. 901 * @return bool true 902 * @throws ddl_change_structure_exception A DDL specific exception is thrown for any errors. 903 */ 904 public function change_database_structure($sql, $tablenames = null) { 905 $this->get_manager(); // Includes DDL exceptions classes ;-) 906 $sqls = (array)$sql; 907 908 try { 909 foreach ($sqls as $sql) { 910 $this->query_start($sql, null, SQL_QUERY_STRUCTURE); 911 $stmt = $this->parse_query($sql); 912 $result = oci_execute($stmt, $this->commit_status); 913 $this->query_end($result, $stmt); 914 oci_free_statement($stmt); 915 } 916 } catch (ddl_change_structure_exception $e) { 917 $this->reset_caches($tablenames); 918 throw $e; 919 } 920 921 $this->reset_caches($tablenames); 922 return true; 923 } 924 925 protected function bind_params($stmt, array &$params=null, $tablename=null, array &$descriptors = null) { 926 if ($params) { 927 $columns = array(); 928 if ($tablename) { 929 $columns = $this->get_columns($tablename); 930 } 931 foreach($params as $key => $value) { 932 // Decouple column name and param name as far as sometimes they aren't the same 933 if ($key == 'o_newfieldtoset') { // found case where column and key diverge, handle that 934 $columnname = key($value); // columnname is the key of the array 935 $params[$key] = $value[$columnname]; // set the proper value in the $params array and 936 $value = $value[$columnname]; // set the proper value in the $value variable 937 } else { 938 $columnname = preg_replace('/^o_/', '', $key); // Default columnname (for DB introspecting is key), but... 939 } 940 // Continue processing 941 // Now, handle already detected LOBs 942 if (is_array($value)) { // Let's go to bind special cases (lob descriptors) 943 if (isset($value['clob'])) { 944 $lob = oci_new_descriptor($this->oci, OCI_DTYPE_LOB); 945 if ($descriptors === null) { 946 throw new coding_exception('moodle_database::bind_params() $descriptors not specified for clob'); 947 } 948 $descriptors[] = $lob; 949 oci_bind_by_name($stmt, $key, $lob, -1, SQLT_CLOB); 950 $lob->writeTemporary($this->oracle_dirty_hack($tablename, $columnname, $params[$key]['clob']), OCI_TEMP_CLOB); 951 continue; // Column binding finished, go to next one 952 } else if (isset($value['blob'])) { 953 $lob = oci_new_descriptor($this->oci, OCI_DTYPE_LOB); 954 if ($descriptors === null) { 955 throw new coding_exception('moodle_database::bind_params() $descriptors not specified for clob'); 956 } 957 $descriptors[] = $lob; 958 oci_bind_by_name($stmt, $key, $lob, -1, SQLT_BLOB); 959 $lob->writeTemporary($params[$key]['blob'], OCI_TEMP_BLOB); 960 continue; // Column binding finished, go to next one 961 } 962 } else { 963 // If, at this point, the param value > 4000 (bytes), let's assume it's a clob 964 // passed in an arbitrary sql (not processed by normalise_value() ever, 965 // and let's handle it as such. This will provide proper binding of CLOBs in 966 // conditions and other raw SQLs not covered by the above function. 967 if (strlen($value) > 4000) { 968 $lob = oci_new_descriptor($this->oci, OCI_DTYPE_LOB); 969 if ($descriptors === null) { 970 throw new coding_exception('moodle_database::bind_params() $descriptors not specified for clob'); 971 } 972 $descriptors[] = $lob; 973 oci_bind_by_name($stmt, $key, $lob, -1, SQLT_CLOB); 974 $lob->writeTemporary($this->oracle_dirty_hack($tablename, $columnname, $params[$key]), OCI_TEMP_CLOB); 975 continue; // Param binding finished, go to next one. 976 } 977 } 978 // TODO: Put proper types and length is possible (enormous speedup) 979 // Arrived here, continue with standard processing, using metadata if possible 980 if (isset($columns[$columnname])) { 981 $type = $columns[$columnname]->meta_type; 982 $maxlength = $columns[$columnname]->max_length; 983 } else { 984 $type = '?'; 985 $maxlength = -1; 986 } 987 switch ($type) { 988 case 'I': 989 case 'R': 990 // TODO: Optimise 991 oci_bind_by_name($stmt, $key, $params[$key]); 992 break; 993 994 case 'N': 995 case 'F': 996 // TODO: Optimise 997 oci_bind_by_name($stmt, $key, $params[$key]); 998 break; 999 1000 case 'B': 1001 // TODO: Only arrive here if BLOB is null: Bind if so, else exception! 1002 // don't break here 1003 1004 case 'X': 1005 // TODO: Only arrive here if CLOB is null or <= 4000 cc, else exception 1006 // don't break here 1007 1008 default: // Bind as CHAR (applying dirty hack) 1009 // TODO: Optimise 1010 $params[$key] = $this->oracle_dirty_hack($tablename, $columnname, $params[$key]); 1011 // Because of PHP7 bug (https://bugs.php.net/bug.php?id=72524) it seems that it's 1012 // impossible to bind NULL values in a reliable way, let's use empty string 1013 // instead in the mean time. 1014 if ($params[$key] === null && version_compare(PHP_VERSION, '7.0.0', '>=')) { 1015 $params[$key] = ''; 1016 } 1017 oci_bind_by_name($stmt, $key, $params[$key]); 1018 } 1019 } 1020 } 1021 return $descriptors; 1022 } 1023 1024 protected function free_descriptors($descriptors) { 1025 foreach ($descriptors as $descriptor) { 1026 // Because all descriptors used in the driver come from LOB::writeTemporary() calls 1027 // we can safely close them here unconditionally. 1028 $descriptor->close(); 1029 // Free resources. 1030 oci_free_descriptor($descriptor); 1031 } 1032 } 1033 1034 /** 1035 * This function is used to convert all the Oracle 1-space defaults to the empty string 1036 * like a really DIRTY HACK to allow it to work better until all those NOT NULL DEFAULT '' 1037 * fields will be out from Moodle. 1038 * @param string the string to be converted to '' (empty string) if it's ' ' (one space) 1039 * @param mixed the key of the array in case we are using this function from array_walk, 1040 * defaults to null for other (direct) uses 1041 * @return boolean always true (the converted variable is returned by reference) 1042 */ 1043 public static function onespace2empty(&$item, $key=null) { 1044 $item = ($item === ' ') ? '' : $item; 1045 return true; 1046 } 1047 1048 /** 1049 * Execute general sql query. Should be used only when no other method suitable. 1050 * Do NOT use this to make changes in db structure, use database_manager methods instead! 1051 * @param string $sql query 1052 * @param array $params query parameters 1053 * @return bool true 1054 * @throws dml_exception A DML specific exception is thrown for any errors. 1055 */ 1056 public function execute($sql, array $params=null) { 1057 list($sql, $params, $type) = $this->fix_sql_params($sql, $params); 1058 1059 if (strpos($sql, ';') !== false) { 1060 throw new coding_exception('moodle_database::execute() Multiple sql statements found or bound parameters not used properly in query!'); 1061 } 1062 1063 list($sql, $params) = $this->tweak_param_names($sql, $params); 1064 $this->query_start($sql, $params, SQL_QUERY_UPDATE); 1065 $stmt = $this->parse_query($sql); 1066 $descriptors = array(); 1067 $this->bind_params($stmt, $params, null, $descriptors); 1068 $result = oci_execute($stmt, $this->commit_status); 1069 $this->free_descriptors($descriptors); 1070 $this->query_end($result, $stmt); 1071 oci_free_statement($stmt); 1072 1073 return true; 1074 } 1075 1076 /** 1077 * Get a single database record as an object using a SQL statement. 1078 * 1079 * The SQL statement should normally only return one record. 1080 * It is recommended to use get_records_sql() if more matches possible! 1081 * 1082 * @param string $sql The SQL string you wish to be executed, should normally only return one record. 1083 * @param array $params array of sql parameters 1084 * @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found; 1085 * IGNORE_MULTIPLE means return first, ignore multiple records found(not recommended); 1086 * MUST_EXIST means throw exception if no record or multiple records found 1087 * @return mixed a fieldset object containing the first matching record, false or exception if error not found depending on mode 1088 * @throws dml_exception A DML specific exception is thrown for any errors. 1089 */ 1090 public function get_record_sql($sql, array $params=null, $strictness=IGNORE_MISSING) { 1091 $strictness = (int)$strictness; 1092 if ($strictness == IGNORE_MULTIPLE) { 1093 // do not limit here - ORA does not like that 1094 $rs = $this->get_recordset_sql($sql, $params); 1095 $result = false; 1096 foreach ($rs as $rec) { 1097 $result = $rec; 1098 break; 1099 } 1100 $rs->close(); 1101 return $result; 1102 } 1103 return parent::get_record_sql($sql, $params, $strictness); 1104 } 1105 1106 /** 1107 * Get a number of records as a moodle_recordset using a SQL statement. 1108 * 1109 * Since this method is a little less readable, use of it should be restricted to 1110 * code where it's possible there might be large datasets being returned. For known 1111 * small datasets use get_records_sql - it leads to simpler code. 1112 * 1113 * The return type is like: 1114 * @see function get_recordset. 1115 * 1116 * @param string $sql the SQL select query to execute. 1117 * @param array $params array of sql parameters 1118 * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set). 1119 * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set). 1120 * @return moodle_recordset instance 1121 * @throws dml_exception A DML specific exception is thrown for any errors. 1122 */ 1123 public function get_recordset_sql($sql, array $params=null, $limitfrom=0, $limitnum=0) { 1124 1125 list($sql, $params, $type) = $this->fix_sql_params($sql, $params); 1126 1127 list($rawsql, $params) = $this->get_limit_sql($sql, $params, $limitfrom, $limitnum); 1128 1129 list($rawsql, $params) = $this->tweak_param_names($rawsql, $params); 1130 $this->query_start($rawsql, $params, SQL_QUERY_SELECT); 1131 $stmt = $this->parse_query($rawsql); 1132 $descriptors = array(); 1133 $this->bind_params($stmt, $params, null, $descriptors); 1134 $result = oci_execute($stmt, $this->commit_status); 1135 $this->free_descriptors($descriptors); 1136 $this->query_end($result, $stmt); 1137 1138 return $this->create_recordset($stmt); 1139 } 1140 1141 protected function create_recordset($stmt) { 1142 return new oci_native_moodle_recordset($stmt); 1143 } 1144 1145 /** 1146 * Get a number of records as an array of objects using a SQL statement. 1147 * 1148 * Return value is like: 1149 * @see function get_records. 1150 * 1151 * @param string $sql the SQL select query to execute. The first column of this SELECT statement 1152 * must be a unique value (usually the 'id' field), as it will be used as the key of the 1153 * returned array. 1154 * @param array $params array of sql parameters 1155 * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set). 1156 * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set). 1157 * @return array of objects, or empty array if no records were found 1158 * @throws dml_exception A DML specific exception is thrown for any errors. 1159 */ 1160 public function get_records_sql($sql, array $params=null, $limitfrom=0, $limitnum=0) { 1161 1162 list($sql, $params, $type) = $this->fix_sql_params($sql, $params); 1163 1164 list($rawsql, $params) = $this->get_limit_sql($sql, $params, $limitfrom, $limitnum); 1165 1166 list($rawsql, $params) = $this->tweak_param_names($rawsql, $params); 1167 $this->query_start($rawsql, $params, SQL_QUERY_SELECT); 1168 $stmt = $this->parse_query($rawsql); 1169 $descriptors = array(); 1170 $this->bind_params($stmt, $params, null, $descriptors); 1171 $result = oci_execute($stmt, $this->commit_status); 1172 $this->free_descriptors($descriptors); 1173 $this->query_end($result, $stmt); 1174 1175 $records = null; 1176 oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_ROW); 1177 oci_free_statement($stmt); 1178 1179 $return = array(); 1180 1181 foreach ($records as $row) { 1182 $row = array_change_key_case($row, CASE_LOWER); 1183 unset($row['oracle_rownum']); 1184 array_walk($row, array('oci_native_moodle_database', 'onespace2empty')); 1185 $id = reset($row); 1186 if (isset($return[$id])) { 1187 $colname = key($row); 1188 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); 1189 } 1190 $return[$id] = (object)$row; 1191 } 1192 1193 return $return; 1194 } 1195 1196 /** 1197 * Selects records and return values (first field) as an array using a SQL statement. 1198 * 1199 * @param string $sql The SQL query 1200 * @param array $params array of sql parameters 1201 * @return array of values 1202 * @throws dml_exception A DML specific exception is thrown for any errors. 1203 */ 1204 public function get_fieldset_sql($sql, array $params=null) { 1205 list($sql, $params, $type) = $this->fix_sql_params($sql, $params); 1206 1207 list($sql, $params) = $this->tweak_param_names($sql, $params); 1208 $this->query_start($sql, $params, SQL_QUERY_SELECT); 1209 $stmt = $this->parse_query($sql); 1210 $descriptors = array(); 1211 $this->bind_params($stmt, $params, null, $descriptors); 1212 $result = oci_execute($stmt, $this->commit_status); 1213 $this->free_descriptors($descriptors); 1214 $this->query_end($result, $stmt); 1215 1216 $records = null; 1217 oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_COLUMN); 1218 oci_free_statement($stmt); 1219 1220 $return = reset($records); 1221 array_walk($return, array('oci_native_moodle_database', 'onespace2empty')); 1222 1223 return $return; 1224 } 1225 1226 /** 1227 * Insert new record into database, as fast as possible, no safety checks, lobs not supported. 1228 * @param string $table name 1229 * @param mixed $params data record as object or array 1230 * @param bool $returnit return it of inserted record 1231 * @param bool $bulk true means repeated inserts expected 1232 * @param bool $customsequence true if 'id' included in $params, disables $returnid 1233 * @return bool|int true or new id 1234 * @throws dml_exception A DML specific exception is thrown for any errors. 1235 */ 1236 public function insert_record_raw($table, $params, $returnid=true, $bulk=false, $customsequence=false) { 1237 if (!is_array($params)) { 1238 $params = (array)$params; 1239 } 1240 1241 $returning = ""; 1242 1243 if ($customsequence) { 1244 if (!isset($params['id'])) { 1245 throw new coding_exception('moodle_database::insert_record_raw() id field must be specified if custom sequences used.'); 1246 } 1247 $returnid = false; 1248 } else { 1249 unset($params['id']); 1250 if ($returnid) { 1251 $returning = " RETURNING id INTO :oracle_id"; // crazy name nobody is ever going to use or parameter ;-) 1252 } 1253 } 1254 1255 if (empty($params)) { 1256 throw new coding_exception('moodle_database::insert_record_raw() no fields found.'); 1257 } 1258 1259 $fields = implode(',', array_keys($params)); 1260 $values = array(); 1261 foreach ($params as $pname => $value) { 1262 $values[] = ":$pname"; 1263 } 1264 $values = implode(',', $values); 1265 1266 $sql = "INSERT INTO {" . $table . "} ($fields) VALUES ($values)"; 1267 list($sql, $params, $type) = $this->fix_sql_params($sql, $params); 1268 $sql .= $returning; 1269 1270 $id = 0; 1271 1272 // note we don't need tweak_param_names() here. Placeholders are safe column names. MDL-28080 1273 // list($sql, $params) = $this->tweak_param_names($sql, $params); 1274 $this->query_start($sql, $params, SQL_QUERY_INSERT); 1275 $stmt = $this->parse_query($sql); 1276 if ($returning) { 1277 oci_bind_by_name($stmt, ":oracle_id", $id, 10, SQLT_INT); 1278 } 1279 $descriptors = array(); 1280 $this->bind_params($stmt, $params, $table, $descriptors); 1281 $result = oci_execute($stmt, $this->commit_status); 1282 $this->free_descriptors($descriptors); 1283 $this->query_end($result, $stmt); 1284 oci_free_statement($stmt); 1285 1286 if (!$returnid) { 1287 return true; 1288 } 1289 1290 if (!$returning) { 1291 die('TODO - implement oracle 9.2 insert support'); //TODO 1292 } 1293 1294 return (int)$id; 1295 } 1296 1297 /** 1298 * Insert a record into a table and return the "id" field if required. 1299 * 1300 * Some conversions and safety checks are carried out. Lobs are supported. 1301 * If the return ID isn't required, then this just reports success as true/false. 1302 * $data is an object containing needed data 1303 * @param string $table The database table to be inserted into 1304 * @param object $data A data object with values for one or more fields in the record 1305 * @param bool $returnid Should the id of the newly created record entry be returned? If this option is not requested then true/false is returned. 1306 * @return bool|int true or new id 1307 * @throws dml_exception A DML specific exception is thrown for any errors. 1308 */ 1309 public function insert_record($table, $dataobject, $returnid=true, $bulk=false) { 1310 $dataobject = (array)$dataobject; 1311 1312 $columns = $this->get_columns($table); 1313 if (empty($columns)) { 1314 throw new dml_exception('ddltablenotexist', $table); 1315 } 1316 1317 $cleaned = array(); 1318 1319 foreach ($dataobject as $field=>$value) { 1320 if ($field === 'id') { 1321 continue; 1322 } 1323 if (!isset($columns[$field])) { // Non-existing table field, skip it 1324 continue; 1325 } 1326 $column = $columns[$field]; 1327 $cleaned[$field] = $this->normalise_value($column, $value); 1328 } 1329 1330 return $this->insert_record_raw($table, $cleaned, $returnid, $bulk); 1331 } 1332 1333 /** 1334 * Import a record into a table, id field is required. 1335 * Safety checks are NOT carried out. Lobs are supported. 1336 * 1337 * @param string $table name of database table to be inserted into 1338 * @param object $dataobject A data object with values for one or more fields in the record 1339 * @return bool true 1340 * @throws dml_exception A DML specific exception is thrown for any errors. 1341 */ 1342 public function import_record($table, $dataobject) { 1343 $dataobject = (array)$dataobject; 1344 1345 $columns = $this->get_columns($table); 1346 $cleaned = array(); 1347 1348 foreach ($dataobject as $field=>$value) { 1349 if (!isset($columns[$field])) { 1350 continue; 1351 } 1352 $column = $columns[$field]; 1353 $cleaned[$field] = $this->normalise_value($column, $value); 1354 } 1355 1356 return $this->insert_record_raw($table, $cleaned, false, true, true); 1357 } 1358 1359 /** 1360 * Update record in database, as fast as possible, no safety checks, lobs not supported. 1361 * @param string $table name 1362 * @param mixed $params data record as object or array 1363 * @param bool true means repeated updates expected 1364 * @return bool true 1365 * @throws dml_exception A DML specific exception is thrown for any errors. 1366 */ 1367 public function update_record_raw($table, $params, $bulk=false) { 1368 $params = (array)$params; 1369 1370 if (!isset($params['id'])) { 1371 throw new coding_exception('moodle_database::update_record_raw() id field must be specified.'); 1372 } 1373 1374 if (empty($params)) { 1375 throw new coding_exception('moodle_database::update_record_raw() no fields found.'); 1376 } 1377 1378 $sets = array(); 1379 foreach ($params as $field=>$value) { 1380 if ($field == 'id') { 1381 continue; 1382 } 1383 $sets[] = "$field = :$field"; 1384 } 1385 1386 $sets = implode(',', $sets); 1387 $sql = "UPDATE {" . $table . "} SET $sets WHERE id=:id"; 1388 list($sql, $params, $type) = $this->fix_sql_params($sql, $params); 1389 1390 // note we don't need tweak_param_names() here. Placeholders are safe column names. MDL-28080 1391 // list($sql, $params) = $this->tweak_param_names($sql, $params); 1392 $this->query_start($sql, $params, SQL_QUERY_UPDATE); 1393 $stmt = $this->parse_query($sql); 1394 $descriptors = array(); 1395 $this->bind_params($stmt, $params, $table, $descriptors); 1396 $result = oci_execute($stmt, $this->commit_status); 1397 $this->free_descriptors($descriptors); 1398 $this->query_end($result, $stmt); 1399 oci_free_statement($stmt); 1400 1401 return true; 1402 } 1403 1404 /** 1405 * Update a record in a table 1406 * 1407 * $dataobject is an object containing needed data 1408 * Relies on $dataobject having a variable "id" to 1409 * specify the record to update 1410 * 1411 * @param string $table The database table to be checked against. 1412 * @param object $dataobject An object with contents equal to fieldname=>fieldvalue. Must have an entry for 'id' to map to the table specified. 1413 * @param bool true means repeated updates expected 1414 * @return bool true 1415 * @throws dml_exception A DML specific exception is thrown for any errors. 1416 */ 1417 public function update_record($table, $dataobject, $bulk=false) { 1418 $dataobject = (array)$dataobject; 1419 1420 $columns = $this->get_columns($table); 1421 $cleaned = array(); 1422 1423 foreach ($dataobject as $field=>$value) { 1424 if (!isset($columns[$field])) { 1425 continue; 1426 } 1427 $column = $columns[$field]; 1428 $cleaned[$field] = $this->normalise_value($column, $value); 1429 } 1430 1431 $this->update_record_raw($table, $cleaned, $bulk); 1432 1433 return true; 1434 } 1435 1436 /** 1437 * Set a single field in every table record which match a particular WHERE clause. 1438 * 1439 * @param string $table The database table to be checked against. 1440 * @param string $newfield the field to set. 1441 * @param string $newvalue the value to set the field to. 1442 * @param string $select A fragment of SQL to be used in a where clause in the SQL call. 1443 * @param array $params array of sql parameters 1444 * @return bool true 1445 * @throws dml_exception A DML specific exception is thrown for any errors. 1446 */ 1447 public function set_field_select($table, $newfield, $newvalue, $select, array $params=null) { 1448 1449 if ($select) { 1450 $select = "WHERE $select"; 1451 } 1452 if (is_null($params)) { 1453 $params = array(); 1454 } 1455 1456 // Get column metadata 1457 $columns = $this->get_columns($table); 1458 $column = $columns[$newfield]; 1459 1460 $newvalue = $this->normalise_value($column, $newvalue); 1461 1462 list($select, $params, $type) = $this->fix_sql_params($select, $params); 1463 1464 if (is_bool($newvalue)) { 1465 $newvalue = (int)$newvalue; // prevent "false" problems 1466 } 1467 if (is_null($newvalue)) { 1468 $newsql = "$newfield = NULL"; 1469 } else { 1470 // Set the param to array ($newfield => $newvalue) and key to 'newfieldtoset' 1471 // name in the build sql. Later, bind_params() will detect the value array and 1472 // perform the needed modifications to allow the query to work. Note that 1473 // 'newfieldtoset' is one arbitrary name that hopefully won't be used ever 1474 // in order to avoid problems where the same field is used both in the set clause and in 1475 // the conditions. This was breaking badly in drivers using NAMED params like oci. 1476 $params['newfieldtoset'] = array($newfield => $newvalue); 1477 $newsql = "$newfield = :newfieldtoset"; 1478 } 1479 $sql = "UPDATE {" . $table . "} SET $newsql $select"; 1480 list($sql, $params, $type) = $this->fix_sql_params($sql, $params); 1481 1482 list($sql, $params) = $this->tweak_param_names($sql, $params); 1483 $this->query_start($sql, $params, SQL_QUERY_UPDATE); 1484 $stmt = $this->parse_query($sql); 1485 $descriptors = array(); 1486 $this->bind_params($stmt, $params, $table, $descriptors); 1487 $result = oci_execute($stmt, $this->commit_status); 1488 $this->free_descriptors($descriptors); 1489 $this->query_end($result, $stmt); 1490 oci_free_statement($stmt); 1491 1492 return true; 1493 } 1494 1495 /** 1496 * Delete one or more records from a table which match a particular WHERE clause. 1497 * 1498 * @param string $table The database table to be checked against. 1499 * @param string $select A fragment of SQL to be used in a where clause in the SQL call (used to define the selection criteria). 1500 * @param array $params array of sql parameters 1501 * @return bool true 1502 * @throws dml_exception A DML specific exception is thrown for any errors. 1503 */ 1504 public function delete_records_select($table, $select, array $params=null) { 1505 1506 if ($select) { 1507 $select = "WHERE $select"; 1508 } 1509 1510 $sql = "DELETE FROM {" . $table . "} $select"; 1511 1512 list($sql, $params, $type) = $this->fix_sql_params($sql, $params); 1513 1514 list($sql, $params) = $this->tweak_param_names($sql, $params); 1515 $this->query_start($sql, $params, SQL_QUERY_UPDATE); 1516 $stmt = $this->parse_query($sql); 1517 $descriptors = array(); 1518 $this->bind_params($stmt, $params, null, $descriptors); 1519 $result = oci_execute($stmt, $this->commit_status); 1520 $this->free_descriptors($descriptors); 1521 $this->query_end($result, $stmt); 1522 oci_free_statement($stmt); 1523 1524 return true; 1525 } 1526 1527 function sql_null_from_clause() { 1528 return ' FROM dual'; 1529 } 1530 1531 public function sql_bitand($int1, $int2) { 1532 return 'bitand((' . $int1 . '), (' . $int2 . '))'; 1533 } 1534 1535 public function sql_bitnot($int1) { 1536 return '((0 - (' . $int1 . ')) - 1)'; 1537 } 1538 1539 public function sql_bitor($int1, $int2) { 1540 return 'MOODLELIB.BITOR(' . $int1 . ', ' . $int2 . ')'; 1541 } 1542 1543 public function sql_bitxor($int1, $int2) { 1544 return 'MOODLELIB.BITXOR(' . $int1 . ', ' . $int2 . ')'; 1545 } 1546 1547 /** 1548 * Returns the SQL text to be used in order to perform module '%' 1549 * operation - remainder after division 1550 * 1551 * @param integer int1 first integer in the operation 1552 * @param integer int2 second integer in the operation 1553 * @return string the piece of SQL code to be used in your statement. 1554 */ 1555 public function sql_modulo($int1, $int2) { 1556 return 'MOD(' . $int1 . ', ' . $int2 . ')'; 1557 } 1558 1559 public function sql_cast_char2int($fieldname, $text=false) { 1560 if (!$text) { 1561 return ' CAST(' . $fieldname . ' AS INT) '; 1562 } else { 1563 return ' CAST(' . $this->sql_compare_text($fieldname) . ' AS INT) '; 1564 } 1565 } 1566 1567 public function sql_cast_char2real($fieldname, $text=false) { 1568 if (!$text) { 1569 return ' CAST(' . $fieldname . ' AS FLOAT) '; 1570 } else { 1571 return ' CAST(' . $this->sql_compare_text($fieldname) . ' AS FLOAT) '; 1572 } 1573 } 1574 1575 /** 1576 * Returns 'LIKE' part of a query. 1577 * 1578 * @param string $fieldname usually name of the table column 1579 * @param string $param usually bound query parameter (?, :named) 1580 * @param bool $casesensitive use case sensitive search 1581 * @param bool $accensensitive use accent sensitive search (not all databases support accent insensitive) 1582 * @param bool $notlike true means "NOT LIKE" 1583 * @param string $escapechar escape char for '%' and '_' 1584 * @return string SQL code fragment 1585 */ 1586 public function sql_like($fieldname, $param, $casesensitive = true, $accentsensitive = true, $notlike = false, $escapechar = '\\') { 1587 if (strpos($param, '%') !== false) { 1588 debugging('Potential SQL injection detected, sql_like() expects bound parameters (? or :named)'); 1589 } 1590 1591 $LIKE = $notlike ? 'NOT LIKE' : 'LIKE'; 1592 1593 // no accent sensitiveness here for now, sorry 1594 1595 if ($casesensitive) { 1596 return "$fieldname $LIKE $param ESCAPE '$escapechar'"; 1597 } else { 1598 return "LOWER($fieldname) $LIKE LOWER($param) ESCAPE '$escapechar'"; 1599 } 1600 } 1601 1602 public function sql_concat() { 1603 $arr = func_get_args(); 1604 if (empty($arr)) { 1605 return " ' ' "; 1606 } 1607 foreach ($arr as $k => $v) { 1608 if ($v === "' '") { 1609 $arr[$k] = "'*OCISP*'"; // New mega hack. 1610 } 1611 } 1612 $s = $this->recursive_concat($arr); 1613 return " MOODLELIB.UNDO_MEGA_HACK($s) "; 1614 } 1615 1616 public function sql_concat_join($separator="' '", $elements = array()) { 1617 if ($separator === "' '") { 1618 $separator = "'*OCISP*'"; // New mega hack. 1619 } 1620 foreach ($elements as $k => $v) { 1621 if ($v === "' '") { 1622 $elements[$k] = "'*OCISP*'"; // New mega hack. 1623 } 1624 } 1625 for ($n = count($elements)-1; $n > 0 ; $n--) { 1626 array_splice($elements, $n, 0, $separator); 1627 } 1628 if (empty($elements)) { 1629 return " ' ' "; 1630 } 1631 $s = $this->recursive_concat($elements); 1632 return " MOODLELIB.UNDO_MEGA_HACK($s) "; 1633 } 1634 1635 /** 1636 * Constructs 'IN()' or '=' sql fragment 1637 * 1638 * Method overriding {@link moodle_database::get_in_or_equal} to be able to get 1639 * more than 1000 elements working, to avoid ORA-01795. We use a pivoting technique 1640 * to be able to transform the params into virtual rows, so the original IN() 1641 * expression gets transformed into a subquery. Once more, be noted that we shouldn't 1642 * be using ever get_in_or_equal() with such number of parameters (proper subquery and/or 1643 * chunking should be used instead). 1644 * 1645 * @param mixed $items A single value or array of values for the expression. 1646 * @param int $type Parameter bounding type : SQL_PARAMS_QM or SQL_PARAMS_NAMED. 1647 * @param string $prefix Named parameter placeholder prefix (a unique counter value is appended to each parameter name). 1648 * @param bool $equal True means we want to equate to the constructed expression, false means we don't want to equate to it. 1649 * @param mixed $onemptyitems This defines the behavior when the array of items provided is empty. Defaults to false, 1650 * meaning throw exceptions. Other values will become part of the returned SQL fragment. 1651 * @throws coding_exception | dml_exception 1652 * @return array A list containing the constructed sql fragment and an array of parameters. 1653 */ 1654 public function get_in_or_equal($items, $type=SQL_PARAMS_QM, $prefix='param', $equal=true, $onemptyitems=false) { 1655 list($sql, $params) = parent::get_in_or_equal($items, $type, $prefix, $equal, $onemptyitems); 1656 1657 // Less than 1000 elements, nothing to do. 1658 if (count($params) < 1000) { 1659 return array($sql, $params); // Return unmodified. 1660 } 1661 1662 // Extract the interesting parts of the sql to rewrite. 1663 if (preg_match('!(^.*IN \()([^\)]*)(.*)$!', $sql, $matches) === false) { 1664 return array($sql, $params); // Return unmodified. 1665 } 1666 1667 $instart = $matches[1]; 1668 $insql = $matches[2]; 1669 $inend = $matches[3]; 1670 $newsql = ''; 1671 1672 // Some basic verification about the matching going ok. 1673 $insqlarr = explode(',', $insql); 1674 if (count($insqlarr) !== count($params)) { 1675 return array($sql, $params); // Return unmodified. 1676 } 1677 1678 // Arrived here, we need to chunk and pivot the params, building a new sql (params remain the same). 1679 $addunionclause = false; 1680 while ($chunk = array_splice($insqlarr, 0, 125)) { // Each chunk will handle up to 125 (+125 +1) elements (DECODE max is 255). 1681 $chunksize = count($chunk); 1682 if ($addunionclause) { 1683 $newsql .= "\n UNION ALL"; 1684 } 1685 $newsql .= "\n SELECT DECODE(pivot"; 1686 $counter = 1; 1687 foreach ($chunk as $element) { 1688 $newsql .= ",\n {$counter}, " . trim($element); 1689 $counter++; 1690 } 1691 $newsql .= ")"; 1692 $newsql .= "\n FROM dual"; 1693 $newsql .= "\n CROSS JOIN (SELECT LEVEL AS pivot FROM dual CONNECT BY LEVEL <= {$chunksize})"; 1694 $addunionclause = true; 1695 } 1696 1697 // Rebuild the complete IN() clause and return it. 1698 return array($instart . $newsql . $inend, $params); 1699 } 1700 1701 /** 1702 * Mega hacky magic to work around crazy Oracle NULL concats. 1703 * @param array $args 1704 * @return string 1705 */ 1706 protected function recursive_concat(array $args) { 1707 $count = count($args); 1708 if ($count == 1) { 1709 $arg = reset($args); 1710 return $arg; 1711 } 1712 if ($count == 2) { 1713 $args[] = "' '"; 1714 // No return here intentionally. 1715 } 1716 $first = array_shift($args); 1717 $second = array_shift($args); 1718 $third = $this->recursive_concat($args); 1719 return "MOODLELIB.TRICONCAT($first, $second, $third)"; 1720 } 1721 1722 /** 1723 * Returns the SQL for returning searching one string for the location of another. 1724 */ 1725 public function sql_position($needle, $haystack) { 1726 return "INSTR(($haystack), ($needle))"; 1727 } 1728 1729 /** 1730 * Returns the SQL to know if one field is empty. 1731 * 1732 * @param string $tablename Name of the table (without prefix). Not used for now but can be 1733 * necessary in the future if we want to use some introspection using 1734 * meta information against the DB. 1735 * @param string $fieldname Name of the field we are going to check 1736 * @param bool $nullablefield For specifying if the field is nullable (true) or no (false) in the DB. 1737 * @param bool $textfield For specifying if it is a text (also called clob) field (true) or a varchar one (false) 1738 * @return string the sql code to be added to check for empty values 1739 */ 1740 public function sql_isempty($tablename, $fieldname, $nullablefield, $textfield) { 1741 if ($textfield) { 1742 return " (".$this->sql_compare_text($fieldname)." = ' ') "; 1743 } else { 1744 return " ($fieldname = ' ') "; 1745 } 1746 } 1747 1748 public function sql_order_by_text($fieldname, $numchars=32) { 1749 return 'dbms_lob.substr(' . $fieldname . ', ' . $numchars . ',1)'; 1750 } 1751 1752 /** 1753 * Is the required OCI server package installed? 1754 * @return bool 1755 */ 1756 protected function oci_package_installed() { 1757 $sql = "SELECT 1 1758 FROM user_objects 1759 WHERE object_type = 'PACKAGE BODY' 1760 AND object_name = 'MOODLELIB' 1761 AND status = 'VALID'"; 1762 $this->query_start($sql, null, SQL_QUERY_AUX); 1763 $stmt = $this->parse_query($sql); 1764 $result = oci_execute($stmt, $this->commit_status); 1765 $this->query_end($result, $stmt); 1766 $records = null; 1767 oci_fetch_all($stmt, $records, 0, -1, OCI_FETCHSTATEMENT_BY_ROW); 1768 oci_free_statement($stmt); 1769 return isset($records[0]) && reset($records[0]) ? true : false; 1770 } 1771 1772 /** 1773 * Try to add required moodle package into oracle server. 1774 */ 1775 protected function attempt_oci_package_install() { 1776 $sqls = file_get_contents(__DIR__.'/oci_native_moodle_package.sql'); 1777 $sqls = preg_split('/^\/$/sm', $sqls); 1778 foreach ($sqls as $sql) { 1779 $sql = trim($sql); 1780 if ($sql === '' or $sql === 'SHOW ERRORS') { 1781 continue; 1782 } 1783 $this->change_database_structure($sql); 1784 } 1785 } 1786 1787 /** 1788 * Does this driver support tool_replace? 1789 * 1790 * @since Moodle 2.8 1791 * @return bool 1792 */ 1793 public function replace_all_text_supported() { 1794 return true; 1795 } 1796 1797 public function session_lock_supported() { 1798 return true; 1799 } 1800 1801 /** 1802 * Obtain session lock 1803 * @param int $rowid id of the row with session record 1804 * @param int $timeout max allowed time to wait for the lock in seconds 1805 * @return void 1806 */ 1807 public function get_session_lock($rowid, $timeout) { 1808 parent::get_session_lock($rowid, $timeout); 1809 1810 $fullname = $this->dbname.'-'.$this->prefix.'-session-'.$rowid; 1811 $sql = 'SELECT MOODLELIB.GET_LOCK(:lockname, :locktimeout) FROM DUAL'; 1812 $params = array('lockname' => $fullname , 'locktimeout' => $timeout); 1813 $this->query_start($sql, $params, SQL_QUERY_AUX); 1814 $stmt = $this->parse_query($sql); 1815 $this->bind_params($stmt, $params); 1816 $result = oci_execute($stmt, $this->commit_status); 1817 if ($result === false) { // Any failure in get_lock() raises error, causing return of bool false 1818 throw new dml_sessionwait_exception(); 1819 } 1820 $this->query_end($result, $stmt); 1821 oci_free_statement($stmt); 1822 } 1823 1824 public function release_session_lock($rowid) { 1825 if (!$this->used_for_db_sessions) { 1826 return; 1827 } 1828 1829 parent::release_session_lock($rowid); 1830 1831 $fullname = $this->dbname.'-'.$this->prefix.'-session-'.$rowid; 1832 $params = array('lockname' => $fullname); 1833 $sql = 'SELECT MOODLELIB.RELEASE_LOCK(:lockname) FROM DUAL'; 1834 $this->query_start($sql, $params, SQL_QUERY_AUX); 1835 $stmt = $this->parse_query($sql); 1836 $this->bind_params($stmt, $params); 1837 $result = oci_execute($stmt, $this->commit_status); 1838 $this->query_end($result, $stmt); 1839 oci_free_statement($stmt); 1840 } 1841 1842 /** 1843 * Driver specific start of real database transaction, 1844 * this can not be used directly in code. 1845 * @return void 1846 */ 1847 protected function begin_transaction() { 1848 $this->commit_status = OCI_DEFAULT; //Done! ;-) 1849 } 1850 1851 /** 1852 * Driver specific commit of real database transaction, 1853 * this can not be used directly in code. 1854 * @return void 1855 */ 1856 protected function commit_transaction() { 1857 $this->query_start('--oracle_commit', NULL, SQL_QUERY_AUX); 1858 $result = oci_commit($this->oci); 1859 $this->commit_status = OCI_COMMIT_ON_SUCCESS; 1860 $this->query_end($result); 1861 } 1862 1863 /** 1864 * Driver specific abort of real database transaction, 1865 * this can not be used directly in code. 1866 * @return void 1867 */ 1868 protected function rollback_transaction() { 1869 $this->query_start('--oracle_rollback', NULL, SQL_QUERY_AUX); 1870 $result = oci_rollback($this->oci); 1871 $this->commit_status = OCI_COMMIT_ON_SUCCESS; 1872 $this->query_end($result); 1873 } 1874 }
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