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   1  <?php
   2  /**
   3   * This program is free software; you can redistribute it and/or modify
   4   * it under the terms of the GNU General Public License as published by
   5   * the Free Software Foundation; either version 2 of the License, or
   6   * (at your option) any later version.
   7   *
   8   * This program is distributed in the hope that it will be useful,
   9   * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11   * GNU General Public License for more details.
  12   *
  13   * You should have received a copy of the GNU General Public License along
  14   * with this program; if not, write to the Free Software Foundation, Inc.,
  15   * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16   * http://www.gnu.org/copyleft/gpl.html
  17   *
  18   * @file
  19   * @ingroup Maintenance
  20   */
  21  
  22  /**
  23   * When using shared tables that are referenced by foreign keys on local
  24   * tables you have to change the constraints on local tables.
  25   *
  26   * The shared tables have to have GRANT REFERENCE on shared tables to local schema
  27   * i.e.: GRANT REFERENCES (user_id) ON mwuser TO hubclient;
  28   */
  29  
  30  require_once  __DIR__ . '/../Maintenance.php';
  31  
  32  class AlterSharedConstraints extends Maintenance {
  33  	public function __construct() {
  34          parent::__construct();
  35          $this->mDescription = "Alter foreign key to reference master tables in shared database setup.";
  36      }
  37  
  38  	public function getDbType() {
  39          return Maintenance::DB_ADMIN;
  40      }
  41  
  42  	public function execute() {
  43          global $wgSharedDB, $wgSharedTables, $wgSharedPrefix, $wgDBprefix;
  44  
  45          if ( $wgSharedDB == null ) {
  46              $this->output( "Database sharing is not enabled\n" );
  47  
  48              return;
  49          }
  50  
  51          $dbw = wfGetDB( DB_MASTER );
  52          foreach ( $wgSharedTables as $table ) {
  53              $stable = $dbw->tableNameInternal( $table );
  54              if ( $wgSharedPrefix != null ) {
  55                  $ltable = preg_replace( "/^$wgSharedPrefix(.*)/i", "$wgDBprefix\\1", $stable );
  56              } else {
  57                  $ltable = "{$wgDBprefix}{$stable}";
  58              }
  59  
  60              $result = $dbw->query( "SELECT uc.constraint_name, uc.table_name, ucc.column_name,
  61                          uccpk.table_name pk_table_name, uccpk.column_name pk_column_name,
  62                          uc.delete_rule, uc.deferrable, uc.deferred
  63                      FROM user_constraints uc, user_cons_columns ucc, user_cons_columns uccpk
  64                      WHERE uc.constraint_type = 'R'
  65                          AND ucc.constraint_name = uc.constraint_name
  66                          AND uccpk.constraint_name = uc.r_constraint_name
  67                          AND uccpk.table_name = '$ltable'" );
  68              while ( ( $row = $result->fetchRow() ) !== false ) {
  69  
  70                  $this->output( "Altering {$row['constraint_name']} ..." );
  71  
  72                  try {
  73                      $dbw->query( "ALTER TABLE {$row['table_name']}
  74                              DROP CONSTRAINT {$wgDBprefix}{$row['constraint_name']}" );
  75                  } catch ( DBQueryError $exdb ) {
  76                      if ( $exdb->errno != 2443 ) {
  77                          throw $exdb;
  78                      }
  79                  }
  80  
  81                  $deleteRule = $row['delete_rule'] == 'NO ACTION' ? '' : "ON DELETE {$row['delete_rule']}";
  82                  $dbw->query( "ALTER TABLE {$row['table_name']}
  83                          ADD CONSTRAINT {$wgDBprefix}{$row['constraint_name']}
  84                          FOREIGN KEY ({$row['column_name']})
  85                          REFERENCES {$wgSharedDB}.$stable({$row['pk_column_name']})
  86                          {$deleteRule} {$row['deferrable']} INITIALLY {$row['deferred']}" );
  87  
  88                  $this->output( "DONE\n" );
  89              }
  90          }
  91      }
  92  }
  93  
  94  $maintClass = "AlterSharedConstraints";
  95  require_once RUN_MAINTENANCE_IF_MAIN;