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   1  <?php
   2  
   3      /**
   4       * \defgroup Database
   5       *
   6       * <p>This module includes all database-related objects.</p>
   7       *
   8       * <p>The most important one is the Db object, which provides one centralized way to get
   9       * access to the current database connection. In fact, there is no reason for classes that require
  10       * database access to use the PDb framework directly, as the Db::getDb() singleton method will
  11       * transparently load the database information from the configuration file, connect to it and return
  12       * a working connection.</p>
  13       *
  14       * <p>In order to get a working database connection, this is all you need to do:</p>
  15       *
  16       * <pre>
  17       * $db =& Db::getDb();
  18       * </pre>
  19       *
  20       * <p>For those classes that extend the Model base class, the private attribute Model::_db is a database
  21       * connection so there is no need to initialize a new one.</p>
  22       */
  23      
  24      lt_include( PLOG_CLASS_PATH."class/config/configfilestorage.class.php" );
  25      lt_include( PLOG_CLASS_PATH."class/database/pdb/pdb.class.php" );
  26  
  27      /**
  28       * \ingroup Database
  29       *
  30       * Provides a singleton for accessing the db and interfaces with PDb. Please use the 
  31       * getDb() singleton method to get access to the global database object instead of creating
  32        * new objects every time.
  33       */
  34      class Db  
  35      {
  36          var $_prefix;
  37  
  38          /**
  39           * Constructor of the class
  40           */
  41          function Db()
  42          {
  43              
  44          }
  45  
  46          /**
  47           * Singleto method that should be used to get access to the global database connection. This method
  48           * will load the database information from the database configuration file (config/config.properties.php) and
  49           * will initialize a connection based on its information. If it is unable to start a new database connection, this
  50           * method wil stop all processing and display an error message.
  51           *
  52           * @return Returns a reference to a PDb driver, with a working connection to the database.
  53           * @see PDb::getDriver()
  54           */
  55          function &getDb()
  56          {
  57              static $db;
  58  
  59              if( !isset( $db )) {
  60                  // we need to connect to the db
  61                  $fileConfig = new ConfigFileStorage();
  62  
  63                  //$db = NewADOConnection('mysql');
  64                  $db = PDb::getDriver('mysql');
  65  
  66                  $username  = $fileConfig->getValue( "db_username" );
  67                  $password  = $fileConfig->getValue( "db_password" );
  68                  $host      = $fileConfig->getValue( "db_host" );
  69                  $dbname    = $fileConfig->getValue( "db_database" );
  70                  $dbcharset = $fileConfig->getValue( "db_character_set" );
  71                  $dbpersistent   = $fileConfig->getValue( "db_persistent" );
  72                  if($dbpersistent == true) {
  73                      if( !$db->PConnect( $host, $username, $password, $dbname, $dbcharset )) {
  74                          $message = "Fatal error: could not connect to the database!".
  75                                     " Error: ".$db->ErrorMsg();
  76                          throw( new Exception( $message ));
  77                          die();
  78                      }
  79                  }
  80                  else {
  81                      if( !$db->Connect( $host, $username, $password, $dbname, $dbcharset )) {
  82                          $message = "Fatal error: could not connect to the database!".
  83                                     " Error: ".$db->ErrorMsg();
  84                          throw( new Exception( $message ));
  85                          die();
  86                      }
  87                  }
  88  
  89                  // pass the options to the driver, if any
  90                  $db->setDriverOpts( $fileConfig->getValue( "db_options" ));
  91              }
  92              
  93              return $db;
  94          }
  95          
  96          /**
  97           * Creates a new database instance based on the information provided
  98           *
  99           * @param host The database host where to connect
 100           * @param username The username used for the connection
 101           * @param password The password used for the connection
 102           * @param dbname The name of the database
 103           * @param returns a reference to a PDb driver or dies if there was an error connecting
 104           */
 105          function &getNewDb( $host, $username, $password, $dbname ) 
 106          {
 107              static $dbs;
 108              
 109              if( !is_array( $dbs ))
 110                  $dbs = Array();
 111                  
 112              $key = $username.$password.$host.$dbname;
 113                  
 114              if( !isset( $dbs[$key] )) {
 115                  $dbs[$key] = PDb::getDriver('mysql');
 116                  if( !$dbs[$key]->PConnect( $host, $username, $password, $dbname )) {
 117                      throw( new Exception( "getNewDb: Fatal error: could not connect to the database!" ));
 118                      die();
 119                  }
 120              }    
 121              
 122              $conn = $dbs[$key];    
 123              
 124              return( $conn );                
 125          }
 126  
 127          /**
 128           * returns the prefix as configured for this database connection
 129           *
 130           * @return A string containing the database prefix
 131           * @static
 132           */
 133  		function getPrefix()
 134          {
 135              static $prefix;
 136  
 137              if ( isset($prefix) ) {
 138                  return $prefix;
 139              } else {
 140                  $fileConfig = new ConfigFileStorage();
 141                  $prefix = $fileConfig->getValue( "db_prefix" );
 142                  return( $prefix );    
 143              }
 144          }
 145  
 146          /**
 147           * Prepares a string for an SQL query by escaping apostrophe
 148           * characters. If the PHP configuration setting 'magic_quotes_gpc'
 149           * is set to ON, it will first strip the added slashes. Apostrophe
 150           * characters are doubled, conforming with the ANSI SQL standard.
 151           * The SQL parser makes sure that the escape token is not entered
 152           * in the database so there is no need to modify the data when it
 153           * is read from the database.
 154           *
 155           * @param  string $string
 156           * @return string
 157           * @access public
 158           */
 159  		function qstr($string) {
 160  
 161               if (get_magic_quotes_gpc()) {
 162                  $string = stripslashes($string);
 163                  //$string = stripslashes($string);
 164                          $string = str_replace('\\\\', '\\', $string);
 165                          $string = str_replace("\\'", "'", $string);
 166                           $string = str_replace('\\"', '"', $string);
 167               }
 168   
 169              $string = str_replace("\\", "\\\\", $string);
 170               $string = str_replace("'", "''", $string);
 171  
 172              return $string;
 173          }
 174      }
 175  ?>