[SQL] ricavare la tabella di appartenenza

[techno]

come faccio riferimento all'alias???

ho provato così:

          $QueryProv=mysql_query("Select *,'db1' as database from $db1.it_insights as database Where db1.Ident='$idart' UNION Select *,'db2' from $db2.it_news as db2 Where db2.Ident='$idart'") or die (mysql_error());
        $RecProv=mysql_fetch_array($QueryProv);
        echo $RecProv["database"]; 

ma mi da questo errore:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'database from Sql379281_1.it_insights as database Where db1.Ident='NWS3631579267'