“Plugin could not be activated because it triggered a fatal error.”

Question

The code below is contained in a plugin file. It just seeks to execute an update query against the wp database. However, its generating a fatal error.

Fatal error: Cannot redeclare ce3_cleanup()

Do I need to load a config file to get acess to $wpdb->query?

function ce3_cleanup()
{
    $wpdb->query("update wp_postmeta set meta_key=replace(meta_key,'cb2_customHeader','_cb2_customHeader') where meta_key like 'cb2_customHeader'");
    $wpdb->query("update wp_postmeta set meta_key=replace(meta_key,'cb2_customTitle','_cb2_customTitle') where meta_key like 'cb2_customTitle'");
}
register_activation_hook(__FILE__, 'ce3_cleanup');
?>

Answer 1

The recommended way to write that function would be:

function ce3_cleanup() {
    global $wpdb;

    $wpdb->query( "update $wpdb->postmeta set meta_key=replace(meta_key,'cb2_customHeader','_cb2_customHeader') where meta_key like 'cb2_customHeader'" );
    $wpdb->query( "update $wpdb->postmeta set meta_key=replace(meta_key,'cb2_customTitle','_cb2_customTitle') where meta_key like 'cb2_customTitle'" );
}
register_activation_hook( __FILE__, 'ce3_cleanup' );

Answer 2

No, Cannot redeclare... means that you already have a function named ce3_cleanup() somewhere else on your site. Perhaps in another plug-in or in your theme.