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  * @subpackage dml
  37  * @copyright  2008 Petr Skoda (http://skodak.org)
  38  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  39  */
  40
  41 defined('MOODLE_INTERNAL') || die();
  42
  43 // Require the essential
  44 require_once($CFG->libdir.'/dml/moodle_database.php');
  45
  46 /** Return false if record not found, show debug warning if multiple records found */
  47 define('IGNORE_MISSING', 0);
  48 /** Similar to IGNORE_MISSING but does not show debug warning if multiple records found, not recommended to be used */
  49 define('IGNORE_MULTIPLE', 1);
  50 /** Indicates exactly one record must exist */
  51 define('MUST_EXIST', 2);
  52
  53 /**
  54  * DML exception class, use instead of error() in dml code.
  55  */
  56 class dml_exception extends moodle_exception {
  57     /**
  58      * @param string $errorcode
  59      * @param string $a
  60      * @param string $debuginfo
  61      */
  62     function __construct($errorcode, $a=NULL, $debuginfo=null) {
  63         parent::__construct($errorcode, '', '', $a, $debuginfo);
  64     }
  65 }
  66
  67 /**
  68  * DML db connection exception - triggered if database not accessible.
  69  */
  70 class dml_connection_exception extends dml_exception {
  71     /**
  72      * Constructor
  73      * @param string $error
  74      */
  75     function __construct($error) {
  76         $errorinfo = $error;
  77         parent::__construct('dbconnectionfailed', NULL, $errorinfo);
  78     }
  79 }
  80
  81 /**
  82  * DML read exception - triggered by SQL syntax errors, missing tables, etc.
  83  */
  84 class dml_read_exception extends dml_exception {
  85     /** @var string */
  86     public $error;
  87     /** @var string */
  88     public $sql;
  89     /** @var array */
  90     public $params;
  91
  92     /**
  93      * Constructor
  94      * @param string $error
  95      * @param string $sql
  96      * @param array $params
  97      */
  98     function __construct($error, $sql=null, array $params=null) {
  99         $this->error  = $error;
 100         $this->sql    = $sql;
 101         $this->params = $params;
 102         $errorinfo = $error."\n".$sql."\n[".var_export($params, true).']';
 103         parent::__construct('dmlreadexception', NULL, $errorinfo);
 104     }
 105 }
 106
 107 /**
 108  * Caused by multiple records found in get_record() call.
 109  */
 110 class dml_multiple_records_exception extends dml_exception {
 111     /** @var string */
 112     public $sql;
 113     /** @var array */
 114     public $params;
 115
 116     /**
 117      * Constructor
 118      * @param string $table table name if known, '' if unknown
 119      * @param string $sql
 120      * @param array $params
 121      */
 122     function __construct($sql='', array $params=null) {
 123         $errorinfo = $sql."\n[".var_export($params, true).']';
 124         parent::__construct('multiplerecordsfound', null, $errorinfo);
 125     }
 126 }
 127
 128 /**
 129  * Caused by missing record that is required for normal operation.
 130  */
 131 class dml_missing_record_exception extends dml_exception {
 132     /** @var string */
 133     public $table;
 134     /** @var string */
 135     public $sql;
 136     /** @var array */
 137     public $params;
 138
 139     /**
 140      * Constructor
 141      * @param string $table table name if known, '' if unknown
 142      * @param string $sql
 143      * @param array $params
 144      */
 145     function __construct($tablename, $sql='', array $params=null) {
 146         if (empty($tablename)) {
 147             $tablename = null;
 148         }
 149         $this->tablename = $tablename;
 150         $this->sql       = $sql;
 151         $this->params    = $params;
 152
 153         switch ($tablename) {
 154             case null:
 155                 $errcode = 'invalidrecordunknown';
 156                 break;
 157             case 'course':
 158                 $errcode = empty($sql) ? 'invalidcourseid' : 'invalidrecord';
 159                 break;
 160             case 'course_module':
 161                 $errcode = 'invalidcoursemodule';
 162                 break;
 163             case 'user':
 164                 $errcode = 'invaliduser';
 165                 break;
 166             default:
 167                 $errcode = 'invalidrecord';
 168                 break;
 169         }
 170         $errorinfo = $sql."\n[".var_export($params, true).']';
 171         parent::__construct($errcode, $tablename, $errorinfo);
 172     }
 173 }
 174
 175 /**
 176  * DML write exception - triggered by SQL syntax errors, missing tables, etc.
 177  */
 178 class dml_write_exception extends dml_exception {
 179     /** @var string */
 180     public $error;
 181     /** @var string */
 182     public $sql;
 183     /** @var array */
 184     public $params;
 185
 186     /**
 187      * Constructor
 188      * @param string $error
 189      * @param string $sql
 190      * @param array $params
 191      */
 192     function __construct($error, $sql=null, array $params=null) {
 193         $this->error  = $error;
 194         $this->sql    = $sql;
 195         $this->params = $params;
 196         $errorinfo = $error."\n".$sql."\n[".var_export($params, true).']';
 197         parent::__construct('dmlwriteexception', NULL, $errorinfo);
 198     }
 199 }
 200
 201 /**
 202  * DML transaction exception - triggered by problems related to DB transactions
 203  */
 204 class dml_transaction_exception extends dml_exception {
 205     /** @var moodle_transaction */
 206     public $transaction;
 207
 208     /**
 209      * Constructor
 210      * @param array $start_backtrace
 211      */
 212     function __construct($debuginfo=null, $transaction=null) {
 213         $this->transaction = $transaction; // TODO: MDL-20625 use the info from $transaction for debugging purposes
 214         parent::__construct('dmltransactionexception', NULL, $debuginfo);
 215     }
 216 }
 217
 218 /**
 219  * Sets up global $DB moodle_database instance
 220  *
 221  * @global object
 222  * @global object
 223  * @return void
 224  */
 225 function setup_DB() {
 226     global $CFG, $DB;
 227
 228     if (isset($DB)) {
 229         return;
 230     }
 231
 232     if (!isset($CFG->dbuser)) {
 233         $CFG->dbuser = '';
 234     }
 235
 236     if (!isset($CFG->dbpass)) {
 237         $CFG->dbpass = '';
 238     }
 239
 240     if (!isset($CFG->dbname)) {
 241         $CFG->dbname = '';
 242     }
 243
 244     if (!isset($CFG->dblibrary)) {
 245         $CFG->dblibrary = 'native';
 246         // use new drivers instead of the old adodb driver names
 247         switch ($CFG->dbtype) {
 248             case 'postgres7' :
 249                 $CFG->dbtype = 'pgsql';
 250                 break;
 251
 252             case 'mssql_n':
 253                 $CFG->dbtype = 'mssql';
 254                 break;
 255
 256             case 'oci8po':
 257                 $CFG->dbtype = 'oci';
 258                 break;
 259
 260             case 'mysql' :
 261                 $CFG->dbtype = 'mysqli';
 262                 break;
 263         }
 264     }
 265
 266     if (!isset($CFG->dboptions)) {
 267         $CFG->dboptions = array();
 268     }
 269
 270     if (isset($CFG->dbpersist)) {
 271         $CFG->dboptions['dbpersist'] = $CFG->dbpersist;
 272     }
 273
 274     if (!$DB = moodle_database::get_driver_instance($CFG->dbtype, $CFG->dblibrary)) {
 275         throw new dml_exception('dbdriverproblem', "Unknown driver $CFG->dblibrary/$CFG->dbtype");
 276     }
 277
 278     try {
 279         $DB->connect($CFG->dbhost, $CFG->dbuser, $CFG->dbpass, $CFG->dbname, $CFG->prefix, $CFG->dboptions);
 280     } catch (moodle_exception $e) {
 281         if (empty($CFG->noemailever) and !empty($CFG->emailconnectionerrorsto)) {
 282             if (file_exists($CFG->dataroot.'/emailcount')){
 283                 $fp = @fopen($CFG->dataroot.'/emailcount', 'r');
 284                 $content = @fread($fp, 24);
 285                 @fclose($fp);
 286                 if((time() - (int)$content) > 600){
 287                     //email directly rather than using messaging
 288                     @mail($CFG->emailconnectionerrorsto,
 289                         'WARNING: Database connection error: '.$CFG->wwwroot,
 290                         'Connection error: '.$CFG->wwwroot);
 291                     $fp = @fopen($CFG->dataroot.'/emailcount', 'w');
 292                     @fwrite($fp, time());
 293                 }
 294             } else {
 295                //email directly rather than using messaging
 296                @mail($CFG->emailconnectionerrorsto,
 297                     'WARNING: Database connection error: '.$CFG->wwwroot,
 298                     'Connection error: '.$CFG->wwwroot);
 299                $fp = @fopen($CFG->dataroot.'/emailcount', 'w');
 300                @fwrite($fp, time());
 301             }
 302         }
 303         // rethrow the exception
 304         throw $e;
 305     }
 306
 307     $CFG->dbfamily = $DB->get_dbfamily(); // TODO: BC only for now
 308
 309     return true;
 310 }