alterSharedConstraints.php

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<?php
require_once( __DIR__ . '/../Maintenance.php' );

class AlterSharedConstraints extends Maintenance {
        public function __construct() {
                parent::__construct();
                $this->mDescription = "Alter foreign key to reference master tables in shared database setup.";
        }

        public function getDbType() {
                return Maintenance::DB_ADMIN;
        }

        public function execute() {
                global $wgSharedDB, $wgSharedTables, $wgSharedPrefix, $wgDBprefix;

                if ( $wgSharedDB == null ) {
                        $this->output( "Database sharing is not enabled\n" );
                        return;
                }

                $dbw = wfGetDB( DB_MASTER );
                foreach ( $wgSharedTables as $table ) {
                        $stable = $dbw->tableNameInternal($table);
                        if ( $wgSharedPrefix != null ) {
                                $ltable = preg_replace( "/^$wgSharedPrefix(.*)/i", "$wgDBprefix\\1", $stable );
                        } else {
                                $ltable = "{$wgDBprefix}{$stable}" ;
                        }

                        $result = $dbw->query( "SELECT uc.constraint_name, uc.table_name, ucc.column_name, uccpk.table_name pk_table_name, uccpk.column_name pk_column_name, uc.delete_rule, uc.deferrable, uc.deferred
                                          FROM user_constraints uc, user_cons_columns ucc, user_cons_columns uccpk
                                         WHERE uc.constraint_type = 'R'
                                           AND ucc.constraint_name = uc.constraint_name
                                           AND uccpk.constraint_name = uc.r_constraint_name
                                           AND uccpk.table_name = '$ltable'" );
                        while (($row = $result->fetchRow()) !== false) {

                                        $this->output( "Altering {$row['constraint_name']} ...");

                                        try {
                                                $dbw->query( "ALTER TABLE {$row['table_name']} DROP CONSTRAINT {$wgDBprefix}{$row['constraint_name']}" );
                                        } catch (DBQueryError $exdb) {
                                                if ($exdb->errno != 2443) {
                                                        throw $exdb;
                                                }
                                        }

                                        $deleteRule = $row['delete_rule'] == 'NO ACTION' ? '' : "ON DELETE {$row['delete_rule']}";
                                        $dbw->query( "ALTER TABLE {$row['table_name']} ADD CONSTRAINT {$wgDBprefix}{$row['constraint_name']}
                                                FOREIGN KEY ({$row['column_name']})
                                                REFERENCES {$wgSharedDB}.$stable({$row['pk_column_name']})
                                                {$deleteRule} {$row['deferrable']} INITIALLY {$row['deferred']}" );

                                        $this->output( "DONE\n" );
                        }
                }
        }

}

$maintClass = "AlterSharedConstraints";
require_once( RUN_MAINTENANCE_IF_MAIN );