multi-site 要如何共用 user 帳號密碼

multi-site 共用同一個 mysql 的話, 例如:
site1:

<?php
//settings.php:
$db_url = 'mysql://root@127.0.0.1/site1';
$db_prefix = array(
       
'default' => '',
       
'users' => 'shared_',
       
'sessions' => 'shared_'
);
?>

site2:

<?php
//settings.php:
$db_url = 'mysql://root@127.0.0.1/site2';
$db_prefix = array(
       
'default' => '',
       
'users' => 'site1.shared_',
       
'sessions' => 'site1.shared_'
);
?>
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