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;