lib/dmllib.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18
  19 /**
  20  * This library contains all the Data Manipulation Language (DML) functions
  21  * used to interact with the DB
  22  *
  23  * This library contains all the Data Manipulation Language (DML) functions
  24  * used to interact with the DB. All the dunctions in this library must be
  25  * generic and work against the major number of RDBMS possible. This is the
  26  * list of currently supported and tested DBs: mysql, postresql, mssql, oracle
  27  *
  28  * This library is automatically included by Moodle core so you never need to
  29  * include it yourself.
  30  *
  31  * For more info about the functions available in this library, please visit:
  32  *     http://docs.moodle.org/en/DML_functions
  33  * (feel free to modify, improve and document such page, thanks!)
  34  *
  35  * @package    core
  36  * @category   dml
  37  * @subpackage 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
  42 defined('MOODLE_INTERNAL') || die();
  43
  44 // Require the essential
  45 require_once($CFG->libdir.'/dml/moodle_database.php');
  46
  47 /** Return false if record not found, show debug warning if multiple records found */
  48 define('IGNORE_MISSING', 0);
  49 /** Similar to IGNORE_MISSING but does not show debug warning if multiple records found, not recommended to be used */
  50 define('IGNORE_MULTIPLE', 1);
  51 /** Indicates exactly one record must exist */
  52 define('MUST_EXIST', 2);
  53
  54 /**
  55  * DML exception class, use instead of error() in dml code.
  56  *
  57  * @package    core
  58  * @category   dml
  59  * @subpackage dml
  60  * @copyright  2008 Petr Skoda (http://skodak.org)
  61  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  62  */
  63 class dml_exception extends moodle_exception {
  64     /**
  65      * @param string $errorcode The name of the string from error.php to print.
  66      * @param string $a Extra words and phrases that might be required in the error string.
  67      * @param string $debuginfo Optional debugging information.
  68      */
  69     function __construct($errorcode, $a=NULL, $debuginfo=null) {
  70         parent::__construct($errorcode, '', '', $a, $debuginfo);
  71     }
  72 }
  73
  74 /**
  75  * DML db connection exception - triggered if database not accessible.
  76  *
  77  * @package    core
  78  * @category   dml
  79  * @subpackage dml
  80  * @copyright  2008 Petr Skoda (http://skodak.org)
  81  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  82  */
  83 class dml_connection_exception extends dml_exception {
  84     /**
  85      * Constructor
  86      * @param string $error Optional debugging information.
  87      */
  88     function __construct($error) {
  89         $errorinfo = $error;
  90         parent::__construct('dbconnectionfailed', NULL, $errorinfo);
  91     }
  92 }
  93
  94 /**
  95  * DML db session wait exception - triggered when session lock request times out.
  96  *
  97  * @package    core
  98  * @category   dml
  99  * @subpackage dml
 100  * @copyright  2008 Petr Skoda (http://skodak.org)
 101  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 102  */
 103 class dml_sessionwait_exception extends dml_exception {
 104     /**
 105      * Constructor
 106      */
 107     function __construct() {
 108         parent::__construct('sessionwaiterr');
 109     }
 110 }
 111
 112 /**
 113  * DML read exception - triggered by some SQL syntax errors, etc.
 114  *
 115  * @package    core
 116  * @category   dml
 117  * @subpackage dml
 118  * @copyright  2008 Petr Skoda (http://skodak.org)
 119  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 120  */
 121 class dml_read_exception extends dml_exception {
 122     /** @var string The name of the string from error.php to print.*/
 123     public $error;
 124     /** @var string The SQL that ran just before this read error.*/
 125     public $sql;
 126     /** @var array The SQL's related parameters.*/
 127     public $params;
 128
 129     /**
 130      * Constructor
 131      * @param string $error The name of the string from error.php to print.
 132      * @param string $sql The SQL that ran just before this read error.
 133      * @param array $params The SQL's related parameters.(optional)
 134      */
 135     function __construct($error, $sql=null, array $params=null) {
 136         $this->error  = $error;
 137         $this->sql    = $sql;
 138         $this->params = $params;
 139         $errorinfo = $error."\n".$sql."\n[".var_export($params, true).']';
 140         parent::__construct('dmlreadexception', NULL, $errorinfo);
 141     }
 142 }
 143
 144 /**
 145  * Caused by multiple records found in get_record() call.
 146  *
 147  * @package    core
 148  * @category   dml
 149  * @subpackage dml
 150  * @copyright  2008 Petr Skoda (http://skodak.org)
 151  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 152  */
 153 class dml_multiple_records_exception extends dml_exception {
 154     /** @var string The SQL that ran just before this read error.*/
 155     public $sql;
 156     /** @var array The SQL's related parameters.*/
 157     public $params;
 158
 159     /**
 160      * Constructor
 161      * @param string $sql The SQL that ran just before this read error.
 162      * @param array $params The SQL's related parameters.(optional)
 163      */
 164     function __construct($sql='', array $params=null) {
 165         $errorinfo = $sql."\n[".var_export($params, true).']';
 166         parent::__construct('multiplerecordsfound', null, $errorinfo);
 167     }
 168 }
 169
 170 /**
 171  * Caused by missing record that is required for normal operation.
 172  *
 173  * @package    core
 174  * @category   dml
 175  * @subpackage dml
 176  * @copyright  2008 Petr Skoda (http://skodak.org)
 177  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 178  */
 179 class dml_missing_record_exception extends dml_exception {
 180     /** @var string A table's name.*/
 181     public $table;
 182     /** @var string An SQL query.*/
 183     public $sql;
 184     /** @var array The SQL's parameters.*/
 185     public $params;
 186
 187     /**
 188      * Constructor
 189      * @param string $tablename The table name if known, '' if unknown.
 190      * @param string $sql Optional SQL query.
 191      * @param array $params Optional SQL query's parameters.
 192      */
 193     function __construct($tablename, $sql='', array $params=null) {
 194         if (empty($tablename)) {
 195             $tablename = null;
 196         }
 197         $this->tablename = $tablename;
 198         $this->sql       = $sql;
 199         $this->params    = $params;
 200
 201         switch ($tablename) {
 202             case null:
 203                 $errcode = 'invalidrecordunknown';
 204                 break;
 205             case 'course':
 206                 $errcode = empty($sql) ? 'invalidcourseid' : 'invalidrecord';
 207                 break;
 208             case 'course_modules':
 209                 $errcode = 'invalidcoursemodule';
 210                 break;
 211             case 'user':
 212                 $errcode = 'invaliduser';
 213                 break;
 214             default:
 215                 $errcode = 'invalidrecord';
 216                 break;
 217         }
 218         $errorinfo = $sql."\n[".var_export($params, true).']';
 219         parent::__construct($errcode, $tablename, $errorinfo);
 220     }
 221 }
 222
 223 /**
 224  * DML write exception - triggered by some SQL syntax errors, etc.
 225  *
 226  * @package    core
 227  * @category   dml
 228  * @subpackage dml
 229  * @copyright  2008 Petr Skoda (http://skodak.org)
 230  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 231  */
 232 class dml_write_exception extends dml_exception {
 233     /** @var string The name of the string from error.php to print.*/
 234     public $error;
 235     /** @var string The SQL that ran just before this write error.*/
 236     public $sql;
 237     /** @var array The SQL's related parameters.*/
 238     public $params;
 239
 240     /**
 241      * Constructor
 242      * @param string $error The name of the string from error.php to print.
 243      * @param string $sql The SQL that ran just before this write error.
 244      * @param array $params The SQL's related parameters.(optional)
 245      */
 246     function __construct($error, $sql=null, array $params=null) {
 247         $this->error  = $error;
 248         $this->sql    = $sql;
 249         $this->params = $params;
 250         $errorinfo = $error."\n".$sql."\n[".var_export($params, true).']';
 251         parent::__construct('dmlwriteexception', NULL, $errorinfo);
 252     }
 253 }
 254
 255 /**
 256  * DML transaction exception - triggered by problems related to DB transactions.
 257  *
 258  * @todo MDL-20625 Use the info from $transaction for debugging purposes.
 259  *
 260  * @package    core
 261  * @category   dml
 262  * @subpackage dml
 263  * @copyright  2008 Petr Skoda (http://skodak.org)
 264  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 265  */
 266 class dml_transaction_exception extends dml_exception {
 267     /** @var moodle_transaction An instance of a transaction.*/
 268     public $transaction;
 269
 270     /**
 271      * Constructor
 272      * @param array $debuginfo Optional debugging information.
 273      * @param moodle_transaction $transaction The instance of the transaction.(Optional)
 274      */
 275     function __construct($debuginfo=null, $transaction=null) {
 276         $this->transaction = $transaction; // TODO: MDL-20625 use the info from $transaction for debugging purposes
 277         parent::__construct('dmltransactionexception', NULL, $debuginfo);
 278     }
 279 }
 280
 281 /**
 282  * Sets up global $DB moodle_database instance
 283  *
 284  * @global stdClass $CFG The global configuration instance.
 285  * @see config.php
 286  * @see config-dist.php
 287  * @global stdClass $DB The global moodle_database instance.
 288  * @return void|bool Returns true when finished setting up $DB. Returns void when $DB has already been set.
 289  */
 290 function setup_DB() {
 291     global $CFG, $DB;
 292
 293     if (isset($DB)) {
 294         return;
 295     }
 296
 297     if (!isset($CFG->dbuser)) {
 298         $CFG->dbuser = '';
 299     }
 300
 301     if (!isset($CFG->dbpass)) {
 302         $CFG->dbpass = '';
 303     }
 304
 305     if (!isset($CFG->dbname)) {
 306         $CFG->dbname = '';
 307     }
 308
 309     if (!isset($CFG->dblibrary)) {
 310         $CFG->dblibrary = 'native';
 311         // use new drivers instead of the old adodb driver names
 312         switch ($CFG->dbtype) {
 313             case 'postgres7' :
 314                 $CFG->dbtype = 'pgsql';
 315                 break;
 316
 317             case 'mssql_n':
 318                 $CFG->dbtype = 'mssql';
 319                 break;
 320
 321             case 'oci8po':
 322                 $CFG->dbtype = 'oci';
 323                 break;
 324
 325             case 'mysql' :
 326                 $CFG->dbtype = 'mysqli';
 327                 break;
 328         }
 329     }
 330
 331     if (!isset($CFG->dboptions)) {
 332         $CFG->dboptions = array();
 333     }
 334
 335     if (isset($CFG->dbpersist)) {
 336         $CFG->dboptions['dbpersist'] = $CFG->dbpersist;
 337     }
 338
 339     if (!$DB = moodle_database::get_driver_instance($CFG->dbtype, $CFG->dblibrary)) {
 340         throw new dml_exception('dbdriverproblem', "Unknown driver $CFG->dblibrary/$CFG->dbtype");
 341     }
 342
 343     try {
 344         $DB->connect($CFG->dbhost, $CFG->dbuser, $CFG->dbpass, $CFG->dbname, $CFG->prefix, $CFG->dboptions);
 345     } catch (moodle_exception $e) {
 346         if (empty($CFG->noemailever) and !empty($CFG->emailconnectionerrorsto)) {
 347             $body = "Connection error: ".$CFG->wwwroot.
 348                 "\n\nInfo:".
 349                 "\n\tError code: ".$e->errorcode.
 350                 "\n\tDebug info: ".$e->debuginfo.
 351                 "\n\tServer: ".$_SERVER['SERVER_NAME']." (".$_SERVER['SERVER_ADDR'].")";
 352             if (file_exists($CFG->dataroot.'/emailcount')){
 353                 $fp = @fopen($CFG->dataroot.'/emailcount', 'r');
 354                 $content = @fread($fp, 24);
 355                 @fclose($fp);
 356                 if((time() - (int)$content) > 600){
 357                     //email directly rather than using messaging
 358                     @mail($CFG->emailconnectionerrorsto,
 359                         'WARNING: Database connection error: '.$CFG->wwwroot,
 360                         $body);
 361                     $fp = @fopen($CFG->dataroot.'/emailcount', 'w');
 362                     @fwrite($fp, time());
 363                 }
 364             } else {
 365                //email directly rather than using messaging
 366                @mail($CFG->emailconnectionerrorsto,
 367                     'WARNING: Database connection error: '.$CFG->wwwroot,
 368                     $body);
 369                $fp = @fopen($CFG->dataroot.'/emailcount', 'w');
 370                @fwrite($fp, time());
 371             }
 372         }
 373         // rethrow the exception
 374         throw $e;
 375     }
 376
 377     $CFG->dbfamily = $DB->get_dbfamily(); // TODO: BC only for now
 378
 379     return true;
 380 }